Comet Hale’s comet Boppa is famous for its uniqueness

Comet Heyla-Boppa (C/1995 O1) is a comet with a long orbit that gained significant attention in the 20th century, becoming one of the brightest comets in recent decades. It remained visible to the naked eye for a remarkable period of 18 months, surpassing the previous record set by the Great Comet of 1811. [2]

Discovered on July 23, 1995 at a substantial distance from the Sun (approximately 7.2 a.e.), it was anticipated to shine brightly as it approached Earth. Despite the challenge of accurately predicting comet brightness, this comet exceeded expectations when it reached perihelion on April 1, 1997. It earned the nickname “Big Comet of 1997.”

The arrival of the Hale-Bopp comet also brought about bewilderment among individuals who hadn’t witnessed such a phenomenon in quite some time. Speculations about an extraterrestrial vessel trailing the comet quickly spread like wildfire. These same speculations acted as the catalyst for a collective act of self-destruction within the ranks of the recently emerged religious sect known as the “Gates of Heaven”.

Discovery

The discovery of the comet was made by two American observers, Alan Hale and Thomas Bopp, who independently spotted it. [3] Hale had spent countless hours searching for comets without success. One night, while observing known comets near his home in New Mexico, he suddenly noticed a faint object with a magnitude of 10.5 near the globular star cluster M70 in the Sagittarius constellation. Hale carefully examined the area and confirmed that there were no other celestial objects nearby. He then observed that the object was moving relative to the background stars, indicating that it was within the solar system. Excited about his find, Hale immediately sent an email to the Central Bureau of Astronomical Telegrams, an organization that keeps track of astronomical discoveries. [4]

Bopp was not in possession of his own telescope. While observing star clusters and galaxies with his friends in Stanfield, Arizona, Bopp witnessed a sudden flash of light through his friend’s telescope. Upon consulting the star charts, Bopp deduced that the flash was actually a new celestial object. He promptly sent a telegram to the same location as Hale to report his findings.

The following day, the existence of a new comet was confirmed and it was named the Hale-Bopp Comet, designated as C/1995 O1. This discovery was officially announced in International Astronomical Union Circular No. 6187. [3] [5] At the time of its discovery, the comet was located 7.1 astronomical units away from the Sun. [6]

Earlier pictures of the comet were quickly uncovered. For instance, Terence Dickinson spotted the comet in his photo captured on May 29, 1995, while Robert McNaught found it in a picture taken on April 27, 1993, a couple of years prior to the comet’s detection. At that particular moment, the comet had a magnitude of 18 m and was positioned 13.0 astronomical units away from the Sun [6]. [6]

The creation of the Great Comet

In May 1996, the comet became observable to the unaided eye. [6] While the rate of brightness growth somewhat decreased in the latter part of the year, [2] researchers made hopeful projections that the comet would exhibit significant luminosity. Due to its close proximity to the Sun, observations were challenging in December 1996, but in January it reemerged and was so radiant that it could even be discerned amidst the illumination of urban streetlights. [7]

As Hale-Bopp’s comet journeyed closer to the Sun, it grew increasingly radiant: by February, its brightness had reached the 2nd magnitude [6] [8], and its distinctive tails – a bluish ionic one, extending away from the Sun, and a yellowish dusty one, curving along the comet’s orbit – became discernible. The occurrence of a solar eclipse in Eastern Siberia and Mongolia on March 9 allowed for the comet to be observed during daylight hours. [9] On March 23, 1997, Hale-Bopp’s comet neared Earth at a close distance of 1.315 a. e. (196.7 million km). [10]

On April 1, 1997, the comet was an extraordinary spectacle when it reached its closest point to the Sun. It had an impressive brightness, with an average magnitude of -0.7 [6] [8], shining even brighter than most stars (excluding Sirius). Its two tails extended across the sky for about 15-20 degrees, and the parts that were not visible to the casual observer extended for about 30-40°. This magnificent comet could be seen in the northern hemisphere all night, right after dusk, which was quite rare for comets passing perihelion.

During that time, the Internet was rapidly developing, and numerous websites emerged that provided detailed information about the comet’s trajectory and even shared daily photographs. The Internet played a crucial role in generating an unprecedented level of public interest in the Hale-Bopp comet [11].

The Hale-Bopp comet had the potential to be even more spectacular. If it had come as close to Earth as comet Hyakutake did in 1996 (0.1 astronomical units), it would have surpassed the brightness of Venus, reaching a magnitude of -5.

The comet is moving away

After passing its closest point to the Sun (perihelion), the Hale-Bopp comet moved into the southern celestial hemisphere and its brightness started to diminish. Observers in the southern hemisphere saw the comet as less impressive, but they witnessed its brightness gradually fading over the second half of 1997. The last sightings of the comet with the naked eye were in December 1997, making it visible for approximately 18 and a half months. This duration broke the previous record of 9 months held by the Great Comet of 1811. [2]

The comet Hale-Bopp is currently moving away from us and its brightness is gradually decreasing. It completed its orbit around Uranus in August 2004 and as of mid-2008, it was approximately 26.8 astronomical units away from the Sun. Despite its distance, astronomers are still able to track its movement. The comet’s unusually long activity is the reason behind this ongoing observation. Recent observations in October 2007 revealed that the comet still possesses a coma with a brightness of around 20 m. The extended activity of the comet is believed to be caused by the slow cooling of its massive nucleus.

The comet is predicted to remain visible through powerful telescopes until approximately 2020, at which point its luminosity will decrease to 30 m . [14] Around the year 4390, the comet is projected to reappear in the vicinity of Earth. It is hypothesized that during one of its future orbits, Hale-Bopp’s comet has a 15% probability of transforming into a near-solar comet, potentially giving rise to a new lineage like the Kreutz family of comets. [15]

Changes in the orbit

The orbital lengths of Sedna and the Hale-Bopp comet can be compared. The Hale-Bopp comet can be seen as the orange line at the bottom of the image, while Sedna is depicted on the left. The yellow sphere represents daylight hours, and the blue sphere represents the shock boundary. The red arrow indicates the position of Voyager 1, while the green arrow represents Pioneer 10. Additionally, the gray ring represents the Kuiper belt, and the small inclined ellipse inside the Kuiper belt represents the orbit of Pluto. The smallest ellipse in the image represents the orbit of Neptune.

Scientific research

During the investigation of the Sun’s proximity, astronomers conducted an in-depth study of the comet. This endeavor led to the discovery of several important and fascinating findings.

Among the most noteworthy outcomes was the identification of a previously unknown type of tail associated with the comet. Alongside the typical gas (ion) and dust tails, there was a faint sodium tail that could only be observed with advanced instruments and a sophisticated filtering system. While sodium streams had been observed in other comets before, none of them had ever formed a tail. However, in the case of Hale-Bopp’s comet, this tail consisted of neutral atoms and extended over a staggering length of nearly 50 million kilometers. [17]

While the dust tail remained stationary behind the comet, tracing its path, and the ion tail pointed directly away from the Sun, the sodium tail extended between the two. This indicates that sodium atoms were being expelled from the comet’s head due to the pressure exerted by light.

Excessive deuterium

Scientists discovered that the comet had elevated levels of deuterium in the form of heavy water: nearly twice the amount found in Earth’s oceans. This suggests that while comet impacts with Earth might have contributed to the planet’s water, they couldn’t have been the sole source (unless, of course, such high concentrations are typical of all comets). [18]

Deuterium has also been detected in other hydrogen compounds. The proportion of these elements varied in various structures, leading astronomers to propose that the ices of the comet were not formed in the protoplanetary disk but in an interstellar cloud. Theoretical models of ice formation in nebulae suggest that the Hale-Bopp comet formed at temperatures ranging from 25 to 45 K. [18]

Compounds of an organic nature

The utilization of a spectroscope to observe Hale-Bopp’s comet has resulted in the identification of a collection of organic compounds, a number of which have never before been observed in comets. These intricate molecules, including acetic and formic acids and acetonitrile, may have originated within the nucleus or been formed through chemical reactions. [19]

Argon detection

The detection of argon in comet Hale-Bopp was significant because it was the first time that this noble gas had been found in a comet. [20] Noble gases are known for being chemically inert and highly volatile, each with its own unique boiling point. This characteristic is useful in monitoring changes in the temperature of cometary ices. For instance, krypton has a boiling point of 16-20 K and it was discovered that its concentration in the comet is 25 times lower than that of the sun [21]. On the other hand, argon has a boiling point of 35-40 K and its concentration in the comet is higher compared to the sun [20].

Rotation

Rotating

Rotational Movement

Turning

Revolution

The comet’s gas emissions and activity were not evenly distributed across its entire surface, but instead showed strong emissions emanating from specific points. By observing these emissions, scientists were able to calculate the rotation period of the comet nucleus. It was discovered that the nucleus of comet Hale-Bopp does indeed rotate [22], but different measurements yielded varying periods, ranging from 11 hours and 20 minutes to 12 hours and 5 minutes [13] [15]. The overlapping rotation periods suggest that the comet nucleus had more than one axis of rotation [23].

Another phase (referred to as the “superphase”), determined by the release of dust particles from the comet’s surface, was found to be 22 days. Then, in March 1997, it was discovered that the comet unexpectedly reversed its rotation direction during the period from February to March. The precise causes of this phenomenon still remain unknown, although it appears to be linked to intense and irregular gas emissions. [13]

The controversy surrounding the satellite

In 1999, a research paper was published proposing the idea of a double nucleus in the comet to explain the observed dust emission. The author’s suggestion was based on theoretical studies and did not involve any direct observations of the secondary nucleus. According to the paper, the secondary nucleus was estimated to have a diameter of 30 km and was located 180 km away from the main core, which had a diameter of 70 km. It was also speculated that the two nuclei would rotate around each other every 3 days. [24]

Using adaptive optics in the period of late 1997 to early 1998, researchers observed a certain duality in the brightness of the core of comet Hale-Bopp. [27] Nonetheless, there is no certainty that this phenomenon can be attributed to the presence of a binary nucleus.

Mysterious Occurrence

Throughout history, comets have been seen as signs of impending doom and have instilled fear in many cultures. The comet in question has attracted a lot of attention due to its long journey to its perihelion, its exceptional size and activity. Moreover, it has also sparked fears related to millenarianism and the anticipated Y2K phenomenon in the year 2000. As a result, numerous outlandish rumors and theories have been circulating about this comet.

“Spaceship from another planet.”

In November 1996, an amateur astronomer named Chuck Schramek from Houston, Texas, USA, captured a digital (CCD) photograph of the comet that revealed a slightly elongated and blurry object nearby. Despite the inability of a computer program to identify this object as a star, Schramek contacted Art Bell Radio to report his discovery of a “Saturn-like object” trailing the comet. UFO enthusiasts, including Cartney Brown, quickly concluded that this object was an alien spacecraft. However, experts in the astronomical community dismissed these claims, stating that the object was actually an 8.5 magnitude star called SAO 141894, which was not detected by Schramek’s computer program due to incorrect user settings. While this confirmation is somewhat hesitant, it does acknowledge the presence of a nearby star, albeit with a different brightness. Furthermore, the experts explained that the bright “rays” emanating from the object at a 45-degree angle were a result of light decay, and they provided several images demonstrating a similar effect (though their images showed four rays instead of two).

In March 1997, a religious sect known as the “Gates of Heaven” decided to use the comet’s sighting as a sign for a collective act of self-destruction. They proclaimed that they would abandon their physical bodies to embark on a voyage to the spacecraft that was supposedly trailing the comet. [31]

The enduring impact of the comet

For nearly everyone who witnessed it, the appearance of Hale-Bopp’s comet was simply a stunning and breathtaking sight in the nighttime sky. The amount of time it was visible, combined with extensive media coverage and internet attention, worked together to make a lasting impact on people. Surpassing even the famous Halley’s comet of 1986, Hale-Bopp’s comet became the most widely observed comet in history, seen by more individuals than any previous sighting of Halley’s comet. This celestial phenomenon shattered numerous records, including being discovered at the greatest distance from the Sun among known comets at that time. It also boasted a potentially enormous nucleus and remained visible for twice as long as any previous comet. Additionally, it maintained a brightness of zero magnitude for an impressive 8 weeks.

Notes

1. ↑Nakano, S.NK 1553 – C/1995 O1 (Hale-Bopp) (English) . OAA computing section circular (February 12, 2008). Verified on November 10, 2008.
2. ↑ 1234Kidger, M. R.; Hurst, G; James, N.The Visual Light Curve Of Comet C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 = The Visual Light Curve Of C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 // . Earth, Moon, and Planets. – 2004. – В. 1-3. – Т. 78. – С. 169-177. – DOI: 10.1023/A:1006228113533.
3. ↑ 12IAU Circular 6187: 1995 O1 (English) . International Astronomical Union (July 23, 1995). Verified on November 10, 2008.
4. ↑ Lemonick, Michael D. Comet of the decade. Part II, Time magazine (March 17, 1997). Verified on November 8, 2008..
5. ↑Thomas BoppAmateur Contributions in the study of Comet Hale-Bopp = Amateur Contributions in the study of Comet Hale-Bopp // Earth, Moon, and Planets. – 1997. – Vol. 1-3. – p. 307-308.
6. ↑ 12345Kronk, Gary W.Comet C/1995 O1 (Hale-Bopp) (English) . Cometography.com. Verified on November 10, 2008.
7. ↑ Browne, Malcolm R. Comet Holds Clues to Birth of Time, The New York Times (March 9, 1997). Verified on November 8, 2008..
8. ↑ 123Seiichi YoshidaThe light curve of comet C/1995 O1 (Hale-Bopp) on December 20, 2007. Verified on November 10, 2008.
9. ↑McGee, H. W.; Poitevin, P.The total solar eclipse of March 9, 1997 = The total solar eclipse of March 9, 1997 // (in Russian). Journal of the British Astronomical Association. – 1997. – V. 3. – VOL. 107. – pp. 112-113.
10. ↑HORIZONS ephemeris generator (English) . JPL. Verified on November 10, 2008.
11. ↑The Trail of Hale-Bopp (English) . Scientific American (March 31, 1997). Verified on November 8, 2008.
12. ↑Szabó, Gy. M.; Kiss, L. L.; Sárneczky, K.Cometary activity at a distance of 25.7 astronomical units: The Hale-Bopp comet’s state 11 years after its closest approach to the Sun = Cometary Activity at 25.7 AU: Hale-Bopp 11 Years after Perihelion // The Astrophysical Journal. – 2008. – V. 2. – VOL. 677. – P. L121-L124. – DOI: 10.1086/588095. – arXiv:0803.1505.
13. ↑ 123Gnedin Y. N. Astronomical observations of the most significant comet in history. – op. cit. ed.
14. ↑West, Richard M.Comet Hale-Bopp. European Southern Observatory (February 7, 1997). Checked November 8, 2008.
15. ↑ 12Bailey, M. E.; Emel'yanenko, V. V.; Hahn, G.; et al.Orbital trajectory changes of Comet 1995 O1 Hale-Bopp = Orbital trajectory changes of Comet 1995 O1 Hale-Bopp // Monthly Notices of the Royal Astronomical Society. Monthly Notices of the Royal Astronomical Society. – 1996. – V. 3. – VOL. 281. – С. 916-924.
16. ↑ 12Yeomans, DonComet Hale-Bopp Orbit and Ephemeris Information (English) . NASA/JPL (April 10, 1997). Checked November 8, 2008.
17. ↑Cremonese, G.; Boehnhardt, H.; Crovisier J.; et al. Neutral Sodium from Comet Hale-Bopp: A Third Type of Tail // The Astrophysical Journal Letters. — 1997. — Т. 490. — С. L199—L202. — DOI: 10.1086/311040
18. ↑ 12Meier, Roland; Owen, Tobias C. Cometary Deuterium // Space Science Reviews. — 1999. — Vol. 1—2. — Vol. 90. — P. 33—43. — DOI: 10.1023/A:1005269208310
19. ↑Rodgers, S. D.; Charnley, S. B. Organic synthesis in the coma of Comet Hale–Bopp? // Monthly Notices of the Royal Astronomical Society. — 2002. — Vol. 4. — Vol. 320. — P. L61—L64. — DOI: 10.1046/j.1365-8711.2001.04208.x
20. ↑ 123Stern, S. A.; Slater, D. C.; Festou, M. C.; et al.The Discovery of Argon in Comet C/1995 O1 (Hale-Bopp) // The Astrophysical Journal. — 2000. — Vol. 2. — Vol. 544. — P. L169—L172. — DOI: 10.1086/317312
21. ↑Krasnopolsky, V. A.; Mumma, M. J.; Abbott, M.; et al.Detection of Soft X-rays and a Sensitive Search for Noble Gases in Comet Hale-Bopp (C/1995 O1) // Science. — 1997. — Vol. 277. — pp. 1488—1491. — DOI: 10.1126/science.277.5331.1488
22. ↑Bergeron, DenisRotation Animation (in English) . NASA/JPL. Accessed November 10, 2008.
23. ↑Licandro, Javier; Bellot Rubio, Luis R., Boehnhardt, Hermann; et al. The Rotation Period of C/1995 O1 (Hale-Bopp) // The Astrophysical Journal Letters. — 1998. — Vol. 501. — pp. L221—L225. — DOI: 10.1086/311465
24. ↑Sekanina, Z. Detection of a Satellite Orbiting The Nucleus of Comet Hale–Bopp (C/1995 O1) // Earth, Moon, and Planets. — 1997. — Vol. 3. — Vol. 77. — pp. 155—163. — DOI: 10.1023/A:1006230712665
25. ↑McCarthy, D. W.; Stolovy, S. R.; Campins, H.; et al.Imaging the dynamics of icy particles in Comet Hale-Bopp during its outburst with HST/NICMOS // Icarus. — 2007. — Vol. 1. — Vol. 189. — P. 184—195.
26. ↑Weaver, H. A.; Feldman, P. D.; A’Hearn, M. F.; et al.HST Observations of Comet Hale-Bopp (C/1995 O1) after perihelion // Icarus. — 1999. — Vol. 1. — Vol. 141. — P. 1—12. – DOI: 10.1006/icar.1999.6159
27. ↑Marchis, F.; Boehnhardt, H.; Hainaut, O. R.; Le Mignant, D.Observation of the inner coma of comet C/1995 O1 using adaptive optics. Are there “Hale” and “Bopp” in the Hale-Bopp comet? = Adaptive optics observations of the innermost coma of C/1995 O1. Are there a “Hale” and a “Bopp” in comet Hale-Bopp? Astronomy & Astrophysics. – 1999. – Vol. 349. – P. 985-995.
28. ↑ Jaroff, Leon, Willwerth, James. The man who popularized the legend, Time magazine (April 14, 1997). Checked 2008-11-08.
29. ↑Burnham, Robert; Levy, David H. Great Comets. – Cambridge University Press, 2000. – P. 191. – ISBN 9780521646000
30. ↑Tholen, David J. Unauthorized use of an IfA/UH picture (English) . European Organization for Astronomical Research in the Southern Hemisphere (January 15, 1997). Checked November 8, 2008.
31. ↑Robinson, Wendy GaleHeaven’s Gate: The End // Journal of Computer-Mediated Communication. – 1997. – V. 3. – VOL. 3.

Literature

• Hale-Bopp’s Comet: eagerly awaiting // Nature. – 1996. – No. 5. – p. 75.
• Surdin V. G. The most brilliant comet of the century // Nature. – 1996. – No. 9. – p. 64.
• Chilingarian I. The unforgettable comet // Nature. – 1997. – No. 8. – p. 52-53.
• Comet Hale-Bopp tells… //. Nature. – 1999. – No. 11. – p. 80.
• Comet Hale-Bopp is still active. Nature. – 2001. – No. 9.
• Gnedin Yu. N. Astronomical observations of the comet of the century: new, unexpected results // Soros Educational Journal. – 1999. – No. 6. – p. 82-89.

References

• Publications regarding the Hale-Bopp comet. Astronet. Verified on November 10, 2008.
• Bumagin, AlexanderHale’s comet Bopp. Naked Eye Encyclopedia. SAI MSU. Verified on November 10, 2008.
• Lodrigas, JerryHale-Bopp’s comet: The remarkable comet of 1997. Astronet. Verified on November 10, 2008.
• Maximenko, AnatolyComets. Materials on astronomy. Verified on November 10, 2008.
• Orlov A. S., Simonov G. V.Comet Hale-Bopp. Astronomy for schoolchildren. Verified on November 10, 2008.
• Kronk, Gary W.C/1995 O1 (Hale-Bopp) (English) . Cometography.com. Verified on November 10, 2008.
• Baalke, RonNASA’s webpage about the Hale-Bopp comet (in English). NASA/JPL. Verified on November 10, 2008.
• Meeting an Ancient and Active Acquaintance (Comet after 5 years) (in English). ESO. Verified on November 10, 2008.
• Simulating the orbit of the comet (in English). NASA/JPL. Verified on November 10, 2008.
• Diagram of the comet’s orbit (in English). Shadow and Substance.com. Verified on November 10, 2008.
• Animation of the comet’s core (in English). Revver.com. Verified on November 10, 2008.

Comet Heyla-Boppa (C/1995 O1) is a comet with a long orbit that has become one of the most observed comets of the 20th century and one of the brightest in recent decades. It was visible to the naked eye for an unprecedented 18 months, which is twice as long as the previous record held by the Great Comet of 1811. [2]

Discovered on July 23, 1995, when it was still a great distance away from the Sun (about 7.2 astronomical units), Comet Heyla-Boppa was expected to be quite bright as it approached Earth. Although predicting the brightness of comets is challenging, this comet surpassed expectations when it reached its closest point to the Sun, known as perihelion, on April 1, 1997. It is sometimes referred to as the “Big Comet of 1997.”

The arrival of the Hale-Bopp comet also sparked bewilderment among individuals who had not witnessed such an event in a significant period of time. Speculations regarding the presence of an extraterrestrial spacecraft trailing the comet quickly spread throughout the public domain. These very speculations served as the catalyst for a tragic incident of group suicide within the devoted followers of the emerging religious sect known as the “Gates of Heaven”.

The incredible find

The remarkable comet was independently discovered by two astute observers from the United States, Alan Hale and Thomas Bopp. [3] Hale had tirelessly dedicated countless hours in search of comets, and while observing familiar comets near his residence in New Mexico, he stumbled upon an enigmatic object with a magnitude of 10.5 near the awe-inspiring globular star cluster M70 in the constellation Sagittarius, around midnight. Hale meticulously confirmed that there were no other celestial bodies in close proximity to this cluster. Furthermore, he astutely observed that the object was visibly moving against the backdrop of stars, indicating its presence within our solar system. Subsequently, Hale composed an email to the Central Bureau of Astronomical Telegrams, an organization responsible for monitoring astronomical breakthroughs. [4]

Bopp didn’t possess his own telescope. While he was outside with his companions close to Stanfield, Arizona, observing star clusters and galaxies, he suddenly caught sight of a tiny gleam of light through the eyepiece of his friend’s telescope. After checking the star charts, Bopp realized that the gleam was an entirely new object and promptly sent a telegram to the same location as Hale.

The following morning, the existence of a fresh comet was confirmed, which was subsequently named Hale-Bopp Comet with the official designation C/1995 O1. The discovery was officially announced in International Astronomical Union Circular No. 6187 [3] [5]. At the time of its discovery, the comet was situated at a distance of 7.1 astronomical units from the Sun [6].

Previously captured images of the comet were quickly unearthed. For instance, Terence Dickinson spotted the comet in a photograph he took on May 29, 1995, while Robert McNaught spotted it in an image captured on April 27, 1993, a whole two years prior to its official discovery. At that particular moment, the comet’s magnitude measured 18 m, and it was positioned 13.0 astronomical units away from the Sun [6]. [6]

The comet was first observed by the naked eye in May 1996. [6] While its brightness dimmed slightly in the latter part of the year, [2] experts remained hopeful that the comet would continue to shine brightly. Due to its close proximity to the Sun, observations became challenging in December 1996. However, by January, the comet reappeared and was so luminous that it could even be seen amidst the glow of city streetlights. [7]

As the Hale-Bopp comet approached the Sun, it gradually became brighter and brighter. By February, it had reached a magnitude of 2 [6] [8]. At this point, its tails were clearly visible – a bluish ionic tail that extended in the opposite direction from the Sun, and a yellowish dusty tail that curved along the orbit of the comet. A solar eclipse in Eastern Siberia and Mongolia on March 9 provided a unique opportunity to observe the comet during the day [9]. Finally, on March 23, 1997, the Hale-Bopp comet came closest to Earth, reaching a minimum distance of 1.315 astronomical units (196.7 million km) [10].

On April 1, 1997, when the comet reached its closest distance to the Sun (perihelion), it put on a breathtaking show. With an average magnitude of -0.7 [6] [8], it outshone all other stars (except Sirius), and its two tails extended across the sky for 15-20 degrees (and the parts not visible to the naked eye for 30-40°). The comet could be observed shortly after sunset, and unlike many other “big” comets that passed perihelion, Hale-Bopp’s comet could be seen throughout the entire night in the northern hemisphere.

During that time, the Internet was rapidly growing and many websites started to track the comet’s trajectory and share daily photographs. As a result, the Internet played a crucial role in fueling the unprecedented public fascination with the Hale-Bopp comet. [11]

Hale-Bopp’s comet could have been even more spectacular. If it had approached Earth as closely as comet Hyakutake did in 1996 (0.1 astronomical units), it would have outshined Venus, reaching a magnitude of -5.

The comet is moving away

After passing its closest point to the Sun, the comet moved into the southern celestial hemisphere and its brightness began to diminish. The comet appeared less remarkable to observers in the southern hemisphere, but they were still able to witness its brightness gradually decrease over the second half of 1997. The last confirmed naked-eye sightings of the comet were in December 1997, meaning it remained visible for approximately 18 and a half months. This duration surpassed the previous record of 9 months held by the Great Comet of 1811. [2]

Hale-Bopp’s comet is currently moving away from us, and its brightness is gradually diminishing. It made a close approach to Uranus in August 2004, and as of mid-2008, it was approximately 26.8 astronomical units away from the Sun. Despite its distance, astronomers are still able to track its trajectory. This is primarily because the comet has exhibited an unusually extended period of activity. Recent observations from October 2007 indicate that the comet still possesses a coma with a brightness of around 20 m. [12] The reason behind this prolonged activity is believed to be the gradual cooling of the comet’s massive nucleus. [13]

The comet is anticipated to remain visible through large telescopes until approximately 2020, at which point its luminosity will decrease to 30 m. [14] It is projected that the comet will reappear near Earth around the year 4390. There is speculation that during one of its future returns, Hale-Bopp’s comet possesses a 15% probability of transforming into a near-solar comet and potentially giving rise to a new comet family, similar to the Kreutz family. [15]

Changes in the orbit

Orbital lengths comparison: Sedna (on the left), the Hale-Bopp comet (at the bottom, represented by an orange line); daylight hours (depicted as a yellow sphere), shock boundary (shown as a blue sphere); location of Voyager 1 (indicated by a red arrow) and Pioneer 10 (represented by a green arrow); the Kuiper belt (displayed as a gray ring); orbit of Pluto (represented by a small inclined ellipse inside the Kuiper belt) and Neptune (shown as the smallest ellipse).

The comet most likely reached its closest point to the Sun (perihelion) for the second-to-last time around 4200 years ago. [16] Its orbit is nearly perpendicular to the plane of the Solar System, making close encounters with planets very rare. However, in March 1996, the comet passed within 0.77 astronomical units (a. e.) of Jupiter, which was close enough for the planet’s gravity to influence its trajectory. [16] At the same time, the comet’s farthest point from the Sun (aphelion) moved closer, ranging from 600 to 350 a. e. As a result, the comet’s orbital period was shortened to 2400 years, and it is expected to make its next appearance in the Solar System around 4390.

Scientific investigation

Astronomers conducted thorough research on the comet as it approached the Sun, leading to several important and fascinating discoveries.

One of the most noteworthy findings was the identification of a third type of tail associated with the comet. In addition to the customary gas (ion) and dust tails, a faint sodium tail was observed, requiring advanced instruments and a complex filter system to be visible. While sodium streams had been observed in other comets before, none had ever formed a tail. In the case of Hale-Bopp’s comet, this tail was composed of neutral atoms and extended over a length of nearly 50 million kilometers. [17]

The origin of the sodium was located within the head of the comet, albeit not in the actual nucleus. There are multiple potential processes that could account for the creation of this source, such as collisions between particles of dust surrounding the nucleus, or the release of sodium from these particles due to exposure to ultraviolet light. It is still unclear which of these mechanisms played a more significant role in this particular case.

While the dust tail remained in the wake of the comet, following its trajectory, and the ion tail extended directly away from the Sun, the sodium tail extended between the two. This indicates that sodium atoms were being expelled from the comet’s head due to the pressure exerted by light.

The discovery of the comet revealed that it contained significantly higher levels of deuterium in the form of heavy water compared to Earth’s oceans. This finding suggests that while comet impacts may have contributed to the presence of water on Earth, they cannot be the sole source unless this concentration is typical for all comets. [18]

Additionally, deuterium was detected in other hydrogen compounds within the comet. The ratio of these elements varied in different structures, leading astronomers to propose that the comet’s ices formed in an interstellar cloud rather than the protoplanetary disk. Theoretical models of ice formation in nebulae indicate that the Hale-Bopp comet developed at temperatures ranging from 25-45 K. [18]

Organic compounds

The use of a spectroscope to observe Hale-Bopp’s comet has led to the discovery of a variety of organic compounds, some of which have never before been found in comets. Among these intricate molecules are acetic acid, formic acid, and acetonitrile, which may have originated within the comet’s nucleus or formed through chemical reactions. [19]

Argon detection

Comet Hale-Bopp was the first comet to contain the noble gas argon. [20] Noble gases are chemically unreactive and highly volatile, with varying boiling points. This characteristic is useful for monitoring changes in the temperature of cometary ices. For instance, krypton evaporates at temperatures between 16-20 K, and it was discovered that the amount of krypton in the comet is 25 times lower than that found in the sun [21]. On the other hand, argon has a boiling point of 35-40 K and its concentration in the comet is higher than in the sun [20].

It has been discovered that the temperature of the internal ice of the Hale-Bopp comet never went above 40 K, and at one point, it even exceeded 20 K. If the formation of the solar system happened at temperatures lower than what is currently believed and with a higher amount of initial argon, the existence of argon in the comet suggests that the Hale-Bopp comet originated in the Kuiper belt beyond Neptune’s orbit and later migrated to the Oort cloud. [20]

Rotation

Rotation

is the action or process of rotating or being rotated. It can refer to the movement of an object around a fixed point or axis, or the act of turning or spinning something. In physics, rotation is a fundamental concept that describes the circular motion of an object. It is often measured in terms of angular velocity, which is the rate at which an object rotates in a given time period. Rotation can have various applications and implications in different fields, such as mechanics, engineering, and astronomy. It plays a crucial role in many natural phenomena and man-made systems.

The distribution of the comet’s activity and gas emissions on the surface of the nucleus was not uniform, but rather concentrated at specific points. By observing these emissions, scientists were able to determine the rotation period of the comet’s nucleus. It was discovered that the nucleus of comet Hale-Bopp does indeed rotate [22], although different measurements at different times yielded varying values for the period, ranging from 11 hours and 20 minutes to 12 hours and 5 minutes [13] [15]. The presence of multiple rotation periods suggests that the comet’s nucleus had more than one axis of rotation [23].

Another period (known as the “superperiod”), which was determined based on the release of dust from the surface, was found to be 22 days. Surprisingly, in March 1997 it was discovered that the comet changed its rotation direction from February to March. The exact cause of this behavior is still unknown, although it appears to be related to intense and irregular gas emissions. [13]

The controversy surrounding the satellite

In 1999, a research paper was published proposing the idea of a double nucleus in the comet as an explanation for the observed dust emission. The author’s suggestion was purely theoretical and not based on any direct observations of a secondary nucleus. The paper hypothesized that the secondary nucleus would have a diameter of 30 km, while the main core would measure 70 km. The distance between the two nuclei was estimated to be 180 km, and they were believed to have a mutual rotation period of 3 days [24].

The claims made in this article were challenged by astronomers who are actively working in the field, as they argued that even the high-resolution images captured by the Hubble Telescope did not reveal any evidence of a double nucleus. [25] [26] Additionally, previous observations of comets with double nuclei have shown that they are not stable for long periods of time. The gravitational forces exerted by the Sun and planets often disrupt the orbit of the secondary nucleus, resulting in the fragmentation of the comet.

In late 1997 – early 1998, the use of adaptive optics revealed some variations in the brightness of the nucleus of the Hale-Bopp comet. [27] However, it cannot be definitively concluded that this effect is a result of a double nucleus.

Throughout history, comets have been seen as signs of misfortune by various cultures and have been met with skepticism. This may be due to their lengthy journey towards their closest point to the sun, their unusual size and behavior, as well as the anxieties surrounding the approaching year 2000, also known as “Y2K”. As a result, the comet has sparked numerous outlandish rumors and theories.

“Spaceship from another planet.”

In November 1996, Chuck Schramek, an amateur astronomer from Houston, Texas, USA, captured a digital (CCD) photograph of the comet, revealing a blurry and slightly elongated object next to it. Despite failing to identify this object with a computer program, Schramek reported his discovery of a “Saturn-like object” trailing the comet to Art Bell Radio. This led many UFO enthusiasts, including Cartney Brown, to speculate that an extraterrestrial spacecraft was accompanying the comet. However, some experts in the field of astronomy argued that the object was simply an 8.5 magnitude star called SAO 141894, which was not detected by Schramek’s computer program due to incorrect user settings. While this explanation has been partially confirmed, it should be noted that the nearby star had a different level of brightness. Additionally, the experts explained that the bright “rays” emanating from the object at a 45-degree angle were caused by light decay, and presented several other images with a similar effect (although these images showed four rays instead of two).

In March 1997, a religious sect named the “Gates of Heaven” decided to interpret the comet’s arrival as a sign for a mass suicide event. They believed that by leaving their physical bodies behind, they could embark on a spiritual journey aboard the spaceship accompanying the comet. [31]

The lasting impact of the comet

For the majority of individuals who witnessed it, the comet Hale-Bopp was nothing less than a stunning and breathtaking sight in the evening sky. The ample amount of time it was visible, along with extensive coverage from the media and the internet, played a significant role in making Hale-Bopp’s comet leave a lasting impression on people. In fact, it surpassed Halley’s comet from 1986 and became the most widely observed comet, with more individuals seeing it than any previous appearances of Halley’s comet. This comet achieved numerous milestones, including being discovered at the greatest distance from the Sun compared to other known comets at the time, potentially having the largest nucleus, and being observed for twice as long as any previous record holder. Additionally, it remained brighter than zero magnitude for a remarkable 8 weeks. [2] [8]

Notes

1. ↑Nakano, S.NK 1553 – C/1995 O1 (Hale-Bopp) (English) . OAA computing section circular (February 12, 2008). Checked November 10, 2008.
2. ↑ 1234Kidger, M. R.; Hurst, G; James, N.The Visual Light Curve Of Comet C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 = The Visual Light Curve Of C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 // . Earth, Moon, and Planets. – 2004. – В. 1-3. – Т. 78. – С. 169-177. – DOI: 10.1023/A:1006228113533.
3. ↑ 12IAU Circular 6187: 1995 O1 (English) . International Astronomical Union (July 23, 1995). Checked November 10, 2008.
4. ↑ Lemonick, Michael D. Comet of the decade. Part II, Time magazine (March 17, 1997). Verified on November 8, 2008.
5. ↑Thomas BoppAmateur Contributions in the study of Comet Hale-Bopp = Amateur Contributions in the study of Comet Hale-Bopp // Earth, Moon, and Planets. – 1997. – Vol. 1-3. – p. 307-308.
6. ↑ 12345Kronk, Gary W.Comet C/1995 O1 (Hale-Bopp) (English) . Cometography.com. Verified on November 10, 2008.
7. ↑ Browne, Malcolm R. Comet Holds Clues to Birth of Time, The New York Times (March 9, 1997). Verified on November 8, 2008.
8. ↑ 123Seiichi YoshidaLight curve of comet C/1995 O1 (Hale-Bopp) (December 20, 2007). Verified on November 10, 2008.
9. ↑McGee, H. W.; Poitevin, P.Total solar eclipse of March 9, 1997 = The total solar eclipse of 1997 March 9 // (in Russian). Journal of the British Astronomical Association. – 1997. – V. 3. – VOL. 107. – P. 112-113.
10. ↑HORIZONS ephemeris generator (English) . JPL. Verified on November 10, 2008.
11. ↑The Trail of Hale-Bopp (English) . Scientific American (March 31, 1997). Verified on November 8, 2008.
12. ↑Szabó, Gy. M.; Kiss, L. L.; Sárneczky, K.Cometary activity at 25.7 AU: Hale-Bopp comet 11 years after perihelion = Cometary Activity at 25.7 AU: Hale-Bopp 11 Years after Perihelion // The Astrophysical Journal. – 2008. – V. 2. – VOL. 677. – P. L121-L124. – DOI: 10.1086/588095. – arXiv:0803.1505.
13. ↑ 123Gnedin Y. N. Astronomical observations of the comet of the century. – op. cit. ed.
14. ↑West, Richard M.Comet Hale-Bopp. European Southern Observatory (February 7, 1997). Checked November 8, 2008.
15. ↑ 12Bailey, M. E.; Emel'yanenko, V. V.; Hahn, G.; et al.Orbital evolution of Comet 1995 O1 Hale-Bopp = Orbital evolution of Comet 1995 O1 Hale-Bopp // Monthly Notices of the Royal Astronomical Society. Monthly Notices of the Royal Astronomical Society. – 1996. – V. 3. – VOL. 281. – С. 916-924.
16. ↑ 12Yeomans, DonComet Hale-Bopp Orbit and Ephemeris Information (English) . NASA/JPL (April 10, 1997). Checked November 8, 2008.
17. ↑Cremonese, G.; Boehnhardt, H.; Crovisier J.; et al. Neutral Sodium from Comet Hale-Bopp: A Third Type of Tail // The Astrophysical Journal Letters. — 1997. — Т. 490. — С. L199—L202. — DOI: 10.1086/311040
18. ↑ 12Meier, Roland; Owen, Tobias C. Cometary Deuterium // Space Science Reviews. — 1999. — Vol. 1—2. — Vol. 90. — P. 33—43. — DOI: 10.1023/A:1005269208310
19. ↑Rodgers, S. D.; Charnley, S. B. Organic synthesis in the coma of Comet Hale–Bopp? // Monthly Notices of the Royal Astronomical Society. — 2002. — Vol. 4. — Vol. 320. — P. L61—L64. — DOI: 10.1046/j.1365-8711.2001.04208.x
20. ↑ 123Stern, S. A.; Slater, D. C.; Festou, M. C.; et al.The Discovery of Argon in Comet C/1995 O1 (Hale-Bopp) // The Astrophysical Journal. — 2000. — Vol. 2. — Vol. 544. — P. L169—L172. — DOI: 10.1086/317312
21. ↑Krasnopolsky, V. A.; Mumma, M. J.; Abbott, M.; et al.Detection of Soft X-rays and a Sensitive Search for Noble Gases in Comet Hale-Bopp (C/1995 O1) // Science. — 1997. — Vol. 277. — pp. 1488—1491. — DOI: 10.1126/science.277.5331.1488
22. ↑Bergeron, DenisRotation Animation (Eng.) . NASA/JPL. Verified on November 10, 2008.
23. ↑Licandro, Javier; Bellot Rubio, Luis R., Boehnhardt, Hermann; et al. The Rotation Period of C/1995 O1 (Hale-Bopp) // The Astrophysical Journal Letters. — 1998. — Vol. 501. — pp. L221—L225. — DOI: 10.1086/311465
24. ↑Sekanina, Z. Detection of a Satellite Orbiting The Nucleus of Comet Hale–Bopp (C/1995 O1) // Earth, Moon, and Planets. — 1997. — Vol. 3. — Vol. 77. — pp. 155—163. — DOI: 10.1023/A:1006230712665
25. ↑McCarthy, D. W.; Stolovy, S. R.; Campins, H.; et al.Imaging the dynamics of icy particles in Comet Hale-Bopp during its outburst using HST/NICMOS // Icarus. — 2007. — Vol. 1. — Vol. 189. — P. 184—195.
26. ↑Weaver, H. A.; Feldman, P. D.; A’Hearn, M. F.; et al.Post-Perihelion observations of Comet Hale-Bopp (C/1995 O1) using HST // Icarus. — 1999. — Vol. 1. — Vol. 141. — P. 1—12. – DOI: 10.1006/icar.1999.6159
27. ↑Marchis, F.; Boehnhardt, H.; Hainaut, O. R.; Le Mignant, D.Observation of the inner coma of comet C/1995 O1 using adaptive optics. Are there “Hale” and “Bopp” in the Hale-Bopp comet? = Adaptive optics observations of the innermost coma of C/1995 O1. Are there a “Hale” and a “Bopp” in comet Hale-Bopp? Astronomy & Astrophysics. – 1999. – Vol. 349. – P. 985-995.
28. ↑ Jaroff, Leon, Willwerth, James. The man who popularized the myth, Time magazine (April 14, 1997). Verified on November 8, 2008.
29. ↑Burnham, Robert; Levy, David H. Great Comets. – Cambridge University Press, 2000. – p. 191. – ISBN 9780521646000
30. ↑Tholen, David J. Untruthful utilization of an IfA/UH picture (English) . European Organization for Astronomical Research in the Southern Hemisphere (January 15, 1997). Verified on November 8, 2008.
31. ↑Robinson, Wendy GaleHeaven’s Gate: The End // Journal of Computer-Mediated Communication. – 1997. – V. 3. – VOL. 3.

Literature

• Hale-Bopp’s Comet: eagerly awaiting // Nature. – 1996. – No. 5. – p. 75.
• Surdin V. G. The most luminous comet of the century // Nature. – 1996. – No. 9. – p. 64.
• Chilingarian I. The unforgettable comet // Nature. – 1997. – No. 8. – p. 52-53.
• Comet Hale-Bopp speaks… //. Nature. – 1999. – No. 11. – p. 80.
• Comet Hale-Bopp remains active. Nature. — 2001. — No. 9.
• Gnedin Yu. N. Astronomical observations of the comet of the century: new, unexpected results // Soros Educational Journal. – 1999. – No. 6. – p. 82-89.

References

• Publications regarding the Hale-Bopp comet. Astronet. Verified on November 10, 2008.
• Bumagin, AlexanderHale’s comet Bopp. Naked Eye Encyclopedia. SAI MSU. Verified on November 10, 2008.
• Lodrigas, JerryHale-Bopp’s comet: The remarkable comet of 1997. Astronet. Verified on November 10, 2008.
• Maximenko, AnatolyComets. Materials on astronomy. Verified on November 10, 2008.
• Orlov A. S., Simonov G. V.Comet Hale-Bopp. Astronomy for schoolchildren. Verified on November 10, 2008.
• Kronk, Gary W.C/1995 O1 (Hale-Bopp) (English) . Cometography.com. Verified on November 10, 2008.
• Baalke, Ron NASA’s webpage about the Hale-Bopp comet (in English). NASA/JPL. Verified on November 10, 2008.
• Meeting with an Ancient and Active Acquaintance (Comet after 5 years) (in English). ESO. Verified on November 10, 2008.
• Simulation of the trajectory of the comet (in English). NASA/JPL. Verified on November 10, 2008.
• Diagram of the orbit (in English). Shadow and Substance.com. Verified on November 10, 2008.
• Animation of the nucleus of the comet (in English). Revver.com. Verified on November 10, 2008.

The Comet Heyla-Boppa (C/1995 O1) is a comet with a long orbit that has gained significant attention and observation. It is considered one of the most observed comets of the 20th century and one of the brightest in recent decades. It remained visible to the naked eye for an impressive 18 months, surpassing the previous record set by the Great Comet of 1811. [2]

Discovered on July 23, 1995, the comet was found at a considerable distance from the Sun (about 7.2 a. e.). This suggested that it would also be quite luminous as it approached Earth. While predicting the brightness of comets is challenging, this particular comet exceeded expectations when it reached its closest point to the Sun, known as perihelion, on April 1, 1997. It is sometimes referred to as the “Big Comet of 1997.”

The arrival of Hale-Bopp’s comet also stirred up bewilderment among individuals who had not witnessed such a phenomenon in quite some time. Speculations about an extraterrestrial vessel trailing behind the comet spread like wildfire. These very speculations served as the catalyst for a mass suicide event within the adherents of the recently established religious group “Gates of Heaven”.

The discovery

The detection of the comet was made independently by two American observers, Alan Hale and Thomas Bopp. [3] Hale had dedicated numerous hours in his search for comets, and while observing already known comets near his residence in New Mexico, he unexpectedly came across a hazy 10.5 magnitude entity in the vicinity of the globular star cluster M70 situated in the constellation Sagittarius. Hale initially confirmed that there were no other celestial objects in close proximity to this cluster. Subsequently, he ascertained that the entity was exhibiting noticeable movement against the backdrop of stars (thus indicating its location within the solar system). Hale promptly composed an email to the Central Bureau of Astronomical Telegrams, an entity responsible for monitoring astronomical discoveries. [4]

Bopp was not in possession of his own telescope. While he was outside with his companions near Stanfield, Arizona, observing star clusters and galaxies, he noticed a small flash of light appear before his eyes through the eyepiece of his friend’s telescope. After consulting the star charts, Bopp realized that the flash was an unidentified object and promptly sent a telegram to the same location as Hale.

The following morning, the existence of a novel comet was confirmed and it was given the name Hale-Bopp Comet with the label C/1995 O1. The announcement of this discovery was made in the International Astronomical Union Circular No. 6187. [3] [5] When the comet was first discovered, it was situated 7.1 astronomical units away from the Sun. [6]

There were earlier sightings of the comet that were subsequently found. For instance, on May 29, 1995, Terence Dickinson discovered the comet in his photograph, while Robert McNaught found it in an image captured on April 27, 1993, which was two years prior to the comet’s official discovery. During that period, the comet had an apparent magnitude of 18 m and was located at a distance of 13.0 astronomical units from the Sun [6]. [6]

The creation of the Great Comet

In May 1996, the comet became visible to the naked eye. [6] Though the increase in brightness somewhat slowed down in the latter half of the year, [2] scientists made optimistic predictions about its brightness. Due to its close proximity to the Sun, observations were challenging in December 1996. However, in January, it became visible again and was so bright that it could even be seen in the glow of streetlights in major cities. [7]

As Hale-Bopp’s comet approached the Sun, it gradually became brighter and brighter. By February, it had reached the 2nd magnitude [6] [8], and its distinct tails were visible – a bluish ionic tail pointing away from the Sun and a yellowish dusty tail curving along the comet’s orbit. A solar eclipse in Eastern Siberia and Mongolia on March 9 provided an opportunity to observe the comet during the day [9]. Then, on March 23, 1997, Hale-Bopp’s comet came closest to Earth, reaching a minimum distance of 1.315 astronomical units (196.7 million km) [10].

On April 1, 1997, the comet put on a magnificent display at perihelion. With an average magnitude of -0.7 [6] [8], it outshone every star in the sky (except for Sirius), and its two tails extended across the horizon by 15-20 degrees (and the parts not visible to the casual observer by 30-40°). The comet could be seen shortly after sunset; and despite many “big” comets that passed perihelion being too close to the Sun, Hale-Bopp’s comet could be observed throughout the night in the northern hemisphere.

During that time, the rise of the Internet gave birth to numerous websites that tracked the comet’s trajectory and even shared daily photographs. Consequently, the Internet played a pivotal role in generating an unprecedented public fascination with the Hale-Bopp comet. [11]

The comet Hale-Bopp could have been even more amazing if it had come as close to Earth as comet Hyakutake did in 1996 (0.1 astronomical unit). In that case, it would have surpassed the brightness of Venus, reaching a magnitude of -5.

The comet is moving away

After passing perihelion, the comet moved into the southern celestial hemisphere and its brightness started to fade. Observers in the southern hemisphere saw the comet as much less impressive, but they were able to witness its brightness gradually decreasing over the second half of 1997. The last confirmed naked-eye sightings of the comet were in December 1997, meaning it remained visible for approximately 18 and a half months. This broke the previous record of 9 months set by the Great Comet of 1811. [2]

The Hale-Bopp comet is currently moving away from us and its brightness is gradually decreasing. It completed an orbit around Uranus in August 2004 and is currently located about 26.8 astronomical units from the Sun as of mid-2008. Despite its distance, astronomers are still able to track its movements. This is due to the comet’s remarkably long period of activity. Recent observations in October 2007 show that the comet still possesses a coma with a brightness of approximately 20 m. The prolonged activity of the comet is believed to be caused by the slow cooling of its massive nucleus. [13]

The comet is predicted to remain visible through large telescopes until approximately 2020, at which point its luminosity will decrease to 30 m [14]. Around the year 4390, the comet is projected to make another appearance near Earth. There is speculation that during one of its future returns, Hale-Bopp’s comet has a 15% probability of transforming into a close-to-sun comet and potentially giving rise to a new comet family, similar to the Kreutz family [15].

Alterations in the orbit

A comparison is being made between the lengths of orbits of different celestial bodies. On the left, we have Sedna, and at the bottom, we can see the orbit of the Hale-Bopp comet represented by the orange line. The yellow sphere represents daylight hours, while the blue sphere represents the shock boundary. The red arrow points to the position of Voyager 1, and the green arrow represents Pioneer 10. Furthermore, we can observe the gray ring, which signifies the Kuiper belt. Inside the Kuiper belt, there is a small inclined ellipse that denotes the orbit of Pluto, and the smallest ellipse represents Neptune.

It is highly probable that the comet experienced its penultimate perihelion passage approximately 4200 years ago. [16] Due to its nearly perpendicular orbit to the ecliptic plane, close encounters with planets are extremely rare. However, in March 1996, the comet came within a distance of 0.77 astronomical units from Jupiter – a close enough proximity for the planet’s gravitational pull to influence its trajectory. [16] Concurrently, the comet’s aphelion, the farthest point in its orbit from the Sun, approached within a range of 600 to 350 astronomical units. Consequently, the comet’s orbital period has been shortened to 2400 years, and its next appearance in the Solar System is anticipated around 4390.

Scientific investigation

While examining the Sun, astronomers conducted extensive research on the comet. This led to the discovery of several important and fascinating findings.

One of the most notable outcomes was the identification of a third type of tail on the comet. Alongside the typical ion and dust tails, there was also a faint sodium tail, which could only be observed using advanced instruments and a complex filter system. Although sodium streams had been observed in previous comets, none of them had formed a tail. In the case of Hale-Bopp’s comet, the tail consisted of neutral atoms and extended over a distance of nearly 50 million kilometers. [17]

The sodium within the comet was located in its head, although not in the core itself. There are various potential processes for the creation of this sodium, such as collisions between dust particles surrounding the core or the expulsion of sodium from these particles due to ultraviolet light. It is still unclear which of these mechanisms played a larger role in this particular case.

While the dust tail remained in the wake of the comet, following its path, and the ion tail pointed directly away from the Sun, the sodium tail extended between the two. This indicates that sodium atoms were being propelled out of the comet’s head due to the pressure of light.

Excess deuterium

The comet was discovered to contain elevated levels of deuterium in heavy water form: nearly double the amount found in Earth’s oceans. This implies that while comet impacts on Earth may have contributed significantly to the presence of water on the planet, they cannot be the sole source (unless, of course, such concentrations are common among all comets) [18].

Deuterium was also detected in other hydrogen compounds. The ratio of these elements varied in different structures, leading astronomers to suggest that the comet’s ices were not formed in the protoplanetary disk, but rather in an interstellar cloud. Theoretical models of ice formation in nebulae indicate that the Hale-Bopp comet formed at temperatures ranging from 25 to 45 K [18].

Organic compounds

The spectroscope observations of Hale-Bopp’s comet have discovered the existence of a collection of organic compounds, a few of which have never previously been found in comets. These intricate molecules, like acetic acid, formic acid, and acetonitrile, may have originated from the comet’s nucleus or formed through chemical reactions. [19]

Argon detection

Comet Hale-Bopp made history as the first comet to contain the noble gas argon. [20] Noble gases are known for their chemical stability and high volatility, with each gas having its own unique boiling point. This characteristic is useful for monitoring changes in the temperature of cometary ices. For instance, krypton boils at temperatures between 16-20 K, and it was observed that the comet’s krypton content is 25 times lower than that of the sun. [21] On the other hand, argon has a boiling point of 35-40 K and is found in higher concentrations compared to the sun. [20]

Therefore, it has been determined that the temperature of the inner ices of the Hale-Bopp comet never went beyond 40 K, while at one point their temperature exceeded 20 K. Unless the formation of the solar system took place at temperatures lower than what is currently believed and with a greater amount of initial argon, the presence of argon in the comet indicates that Hale-Bopp’s comet originated beyond the orbit of Neptune, specifically in the Kuiper belt, and later migrated to the Oort cloud. [20]

Spinning

The comet Hale-Bopp exhibited uneven distribution of activity and gas emissions across its nucleus, with strong emissions emanating from specific points. By observing these emissions, scientists were able to determine the rotation period of the comet’s nucleus. It was discovered that the nucleus of comet Hale-Bopp does rotate [22], although different measurements yielded varying values for the period, ranging from 11 hours and 20 minutes to 12 hours and 5 minutes [13] [15]. The presence of multiple rotation periods suggests that the comet nucleus had more than one axis of rotation [23].

There was another period, known as the “superperiod”, which lasted for 22 days and was determined by analyzing dust emissions from the comet’s surface. Interestingly, in March 1997 it was discovered that the comet had unexpectedly reversed its rotation direction between February and March. The exact cause of this behavior is still unknown, but it is believed to be related to intense and irregular gas emissions. [13]

The controversy surrounding the satellite discovery

In the year 1999, a research paper emerged proposing the existence of a double nucleus within the comet in order to explain the peculiar dust emission patterns observed. The author’s argument was largely theoretical and lacked any direct observations of the secondary nucleus. Nonetheless, the paper outlined the anticipated characteristics of this secondary nucleus, speculating a diameter of 30 km, with a primary core measuring 70 km in diameter. The two nuclei were presumed to be separated by a distance of 180 km and were expected to rotate in sync every 3 days. [24]

The claims made in this article were challenged by astronomers who are currently practicing in the field, as they pointed out that even the high-resolution images taken by the Hubble Telescope of the comet did not reveal any evidence of a double nucleus. [25] [26] Moreover, previous observations of comets with double nuclei have shown that they are not stable for long periods of time: the gravitational pull of the Sun and the planets easily disrupts the orbit of the secondary nucleus, leading to the fragmentation of the comet.

Adaptive optics were utilized in late 1997 – early 1998 to reveal some level of duality in the brightness of the Hale-Bopp comet’s nucleus. [27] However, it cannot be definitively confirmed that this effect is a result of a double nucleus.

Unexplained Phenomena

Throughout history, comets have been seen as signs of impending doom by numerous civilizations, leading to a deep sense of unease. This unease can perhaps be attributed to the comet’s lengthy journey to its perihelion, its unusual size and activity, and the widespread apprehension surrounding the millennium bug, also known as “Y2K,” in the year 2000. As a result, the comet has become the focus of numerous strange rumors and theories.

“Spaceship from another planet.”

In November 1996, Chuck Schramek, an amateur astronomer from Houston, Texas, USA, captured a digital (CCD) photograph of the comet, which revealed a blurry and slightly elongated object nearby. Despite the inability of a computer program to identify the object as a star, Schramek reported his discovery of a “Saturn-like object” trailing behind the comet on Art Bell Radio. This sparked the interest of UFO enthusiasts, including Cartney Brown, who speculated that it could be an extraterrestrial spacecraft.

However, experts in the astronomical community quickly debunked these claims. They pointed out that the object in question was actually an 8.5 magnitude star known as SAO 141894. The reason it did not appear in Schramek’s computer program was due to incorrect user settings. While it is true that there was a nearby star, it was of a different magnitude than initially believed.

Furthermore, the experts explained that the bright “rays” emanating from the object at a 45-degree angle were simply a result of light decay. To support their explanation, they provided several images showing a similar effect, although the number of rays differed (their images showed 4 rays instead of 2).

Afterwards, Art Bell went on to claim that he had his own photo of the object – which he received from an anonymous astrophysicist who claimed to confirm the discovery. However, astronomers Oliver Heinot and David Tholen from the University of Hawaii countered that the photo presented was actually a modified version of their own image of the comet. [30]

A few months later, in March 1997, a religious sect known as the “Gates of Heaven” selected the comet’s appearance as a sign for a mass suicide event. They announced that they were shedding their physical bodies in order to embark on a journey aboard the spaceship that was following the comet. [31]

The Legacy of Hale-Bopp’s Comet

Hale-Bopp’s comet captivated the hearts of those who laid eyes on its breathtaking display in the night sky. With an extended viewing period and extensive media coverage, this comet left an indelible mark on people’s memories, even surpassing the fame of Halley’s comet in 1986. In fact, Hale-Bopp became the most widely observed comet in history, attracting a larger audience than any previous sighting of Halley’s comet. Not only did Hale-Bopp break numerous records, such as being discovered at the greatest distance from the Sun among known comets at the time and possibly having the largest nucleus, but it also remained visible at a magnitude of zero for an impressive 8 weeks.

Notes

1. ↑Nakano, S.NK 1553 – C/1995 O1 (Hale-Bopp) (English) . OAA computing section circular (February 12, 2008). Checked November 10, 2008.
2. ↑ 1234Kidger, M. R.; Hurst, G; James, N.The Visual Light Curve Of Comet C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 = The Visual Light Curve Of C/1995 O1 (Hale-Bopp) From Discovery To Late 1997 // . Earth, Moon, and Planets. – 2004. – В. 1-3. – Т. 78. – С. 169-177. – DOI: 10.1023/A:1006228113533.
3. ↑ 12IAU Circular 6187: 1995 O1 (English) . International Astronomical Union (July 23, 1995). Checked November 10, 2008.
4. ↑Thomas Bopp made amateur contributions to the study of Comet Hale-Bopp, as documented in the article “Amateur Contributions in the study of Comet Hale-Bopp” published in the journal Earth, Moon, and Planets in 1997, volume 1-3, pages 307-308.
5. ↑ 12345Gary W. Kronk wrote about Comet C/1995 O1 (Hale-Bopp) on Cometography.com. This information was checked on November 10, 2008.
6. ↑ Malcolm R. Browne discussed the comet in the article “Comet Holds Clues to Birth of Time” published in The New York Times on March 9, 1997. This information was checked on November 8, 2008.
7. ↑ 123Seiichi Yoshida published a light curve of comet C/1995 O1 (Hale-Bopp) on December 20, 2007. This information was checked on November 10, 2008.
8. ↑McGee, H. W.; Poitevin, P.The total solar eclipse that occurred on March 9, 1997 is described in the article “Total solar eclipse of 1997 March 9” published in the Journal of the British Astronomical Association (1997, V. 3, VOL. 107, pp. 112-113) (in Russian).
9. ↑HORIZONS ephemeris generator is a tool provided by JPL for generating ephemerides. It was last checked on November 10, 2008.
10. ↑The Trail of Hale-Bopp is an article published in Scientific American on March 31, 1997. It was last checked on November 8, 2008.
11. ↑Szabó, Gy. M.; Kiss, L. L.; Sárneczky, K.The article “Cometary activity at 25.7 AU: Hale-Bopp comet 11 years after perihelion” provides insights into the activity of the Hale-Bopp comet 11 years after its perihelion passage. It was published in The Astrophysical Journal (2008, V. 2, VOL. 677, pp. L121-L124) and has a DOI: 10.1086/588095. It is also available on arXiv:0803.1505.
12. 123Gnedin Y. N. Astronomical observations of the comet of the century. – op. cit. ed.
13. ↑West, Richard M.Comet Hale-Bopp. European Southern Observatory (February 7, 1997). Checked November 8, 2008.
14. 12Bailey, M. E.; Emel'yanenko, V. V.; Hahn, G.; et al.Orbital evolution of Comet 1995 O1 Hale-Bopp = Orbital evolution of Comet 1995 O1 Hale-Bopp // Monthly Notices of the Royal Astronomical Society. Monthly Notices of the Royal Astronomical Society. – 1996. – V. 3. – VOL. 281. – С. 916-924.
15. 12Yeomans, DonComet Hale-Bopp Orbit and Ephemeris Information (English) . NASA/JPL (April 10, 1997). Checked November 8, 2008.
16. ↑Cremonese, G.; Boehnhardt, H.; Crovisier J.; et al. A Third Type of Tail: Neutral Sodium Observations from Comet Hale-Bopp // The Astrophysical Journal Letters. — 1997. — Vol. 490. — pp. L199—L202. — DOI: 10.1086/311040
17. ↑ 12Meier, Roland; Owen, Tobias C. Cometary Deuterium: Insights from Research on Comet Hale-Bopp // Space Science Reviews. — 1999. — Vol. 1—2. — pp. 33—43. — DOI: 10.1023/A:1005269208310
18. ↑Rodgers, S. D.; Charnley, S. B. Is Organic Synthesis Occurring in the Coma of Comet Hale–Bopp? // Monthly Notices of the Royal Astronomical Society. — 2002. — Vol. 4. — pp. L61—L64. — DOI: 10.1046/j.1365-8711.2001.04208.x
19. ↑ 123Stern, S. A.; Slater, D. C.; Festou, M. C.; et al.The Discovery of Argon in Comet C/1995 O1 (Hale-Bopp) // The Astrophysical Journal. — 2000. — Vol. 2. — pp. L169—L172. — DOI: 10.1086/317312
20. ↑Krasnopolsky, V. A.; Mumma, M. J.; Abbott, M.; et al.Detection of Soft X-rays and a Sensitive Search for Noble Gases in Comet Hale-Bopp (C/1995 O1) // Science. — 1997. — Vol. 277. — pp. 1488—1491. — DOI: 10.1126/science.277.5331.1488
21. ↑Bergeron, DenisRotation Animation (in English) . NASA/JPL. Retrieved November 10, 2008.
22. ↑Licandro, Javier; Bellot Rubio, Luis R., Boehnhardt, Hermann; et al. The Rotation Period of C/1995 O1 (Hale-Bopp) // The Astrophysical Journal Letters. — 1998. — Vol. 501. — pp. L221—L225. — DOI: 10.1086/311465
23. ↑Sekanina, Z. The Discovery of a Satellite Orbiting The Nucleus of Comet Hale–Bopp (C/1995 O1) // Earth, Moon, and Planets. — 1997. — Vol. 3. — pp. 155—163. — DOI: 10.1023/A:1006230712665
24. ↑McCarthy, D. W.; Stolovy, S. R.; Campins, H.; et al.Observing the Dynamics of Icy Particles in Comet Hale–Bopp’s Outburst Using HST/NICMOS // Icarus. — 2007. — Vol. 1. — pp. 184—195.
25. ↑Weaver, H. A.; Feldman, P. D.; A’Hearn, M. F.; et al.HST Observations of Comet Hale-Bopp (C/1995 O1) After Its Perihelion Passage // Icarus. — 1999. — Vol. 1. — pp. 1—12. – DOI: 10.1006/icar.1999.6159
26. ↑Marchis, F.; Boehnhardt, H.; Hainaut, O. R.; Le Mignant, D.Observation of the inner coma of comet C/1995 O1 using adaptive optics. Is there any presence of “Hale” and “Bopp” in the Hale-Bopp comet? = Adaptive optics observations of the closest coma of C/1995 O1. Can we find a “Hale” and a “Bopp” within comet Hale-Bopp? Astronomy & Astrophysics. – 1999. – Vol. 349. – pp. 985-995.
27. ↑ Jaroff, Leon, Willwerth, James. The man who propagated the legend, Time magazine (April 14, 1997). Verified 2008-11-08.
28. ↑Burnham, Robert; Levy, David H. Great Comets. – Cambridge University Press, 2000. – pp. 191. – ISBN 9780521646000
29. ↑Tholen, David J.Fraudulent utilization of a picture from the IfA/UH (English) . European Organization for Astronomical Research in the Southern Hemisphere (January 15, 1997). Verified on November 8, 2008.
30. ↑Robinson, Wendy GaleHeaven’s Gate: The Conclusion // Journal of Computer-Mediated Communication. – 1997. – V. 3. – VOL. 3.

Literature

• Hale-Bopp’s Comet: an eager anticipation // Nature. – 1996. – № 5. – p. 75.
• Surdin V. G. The most brilliant comet of the century // Nature. – 1996. – № 9. – p. 64.
• Chilingarian I. The comet that will never be forgotten // Nature. – 1997. – № 8. – p. 52-53.
• Comet Hale – Boppa speaks… //. Nature. – 1999. – № 11. – p. 80.
• Comet Hale-Bopp is still active. Nature. — 2001. — № 9.
• Gnedin Yu. N. Astronomical observations of the comet of the century: new, unexpected findings // Soros Educational Journal. – 1999. – № 6. – p. 82-89.

References

• Publications about the Hale-Bopp comet. Astronet. Last checked on November 10, 2008.
• Bumagin, Alexander Hale’s comet Bopp. Naked Eye Encyclopedia. SAI MSU. Last checked on November 10, 2008.
• Lodrigas, Jerry Hale-Bopp’s comet: The amazing comet of 1997. Astronet. Last checked on November 10, 2008.
• Maximenko, Anatoly Comets. Materials on astronomy. Last checked on November 10, 2008.
• Orlov A. S., Simonov G. V. Comet Hale-Bopp. Astronomy for students. Last checked on November 10, 2008.
• Kronk, Gary W. C/1995 O1 (Hale-Bopp) (English). Cometography.com. Last checked on November 10, 2008.
• Baalke, Ron NASA’s page on the Hale-Bopp comet (English). NASA/JPL. Checked on November 10, 2008.
• Visiting an Old and Active Friend (Comet after 5 years) (in English). ESO. Checked on November 10, 2008.
• Comet orbit simulation (in English). NASA/JPL. Checked on November 10, 2008.
• Orbit diagram (English). Shadow and Substance.com. Checked on November 10, 2008.
• Animation of the nucleus of the comet (English). Revver.com. Checked on November 10, 2008.

The Hale-Bopp comet, which first appeared in 1995, is one of the most discussed comets.

The continuous radiance of the comet provided a captivating spectacle against a backdrop of vibrant blue, enchanting the hearts of millions. It remained visible to the unaided eye for a duration exceeding 18 months, setting a new record for longevity.

The comet’s remarkable visibility without the aid of optical instruments can be attributed to its impressive dimensions, boasting a nucleus measuring 37.28 miles (60 kilometers) in width. With its lengthy orbital period, currently spanning 2,533 years, it embarks on extended journeys through the vicinity of planets. It is projected to make its return to the inner solar system around the year 4385.

In 1997, Comet Hale-Bopp stole the spotlight as the most frequently captured celestial entity. From 1995 until the conclusion of 1997, the comet remained visible to the naked eye, securing its place as the comet with the lengthiest duration. Its substantial nucleus contributes to its exceptional brightness, and it held the distinction of being the farthest comet detected by amateur astronomers at that time.

Multiple details of various bright comets, such as the Hale-Bopp comet, have been revealed through images captured by the Hubble Space Telescope. The comet, it appears, has a diameter of approximately 24.85 miles (40 kilometers) and completes one rotation every 11.4 hours. Numerous images of Comet Hale-Bopp are accessible, providing significant insights into its luminous nature. In our solar system, Comet Encke possesses the shortest orbital period of any known comet, lasting three years and three months.

Discovery of Hale-Bopp Comet

Hale-Bopp Comet was initially detected on July 23, 1995, by two amateur astronomers who independently observed it. These astronomers were Thomas Bopp and Alan Hale from the United States.

It was observed in the region between Jupiter and Saturn and was approximately 7.2 astronomical units (a.u.) away from the Sun. Astronomers identified it as a large comet due to its close proximity to Earth. In the inner solar system, the orbit of this comet was observed at perihelion on April 1, 1997. This massive comet with a stunning aurora was visible to people worldwide, particularly in the Northern Hemisphere. Some even claim that it appeared so bright that it surpassed the size of Halley’s Comet, which was discovered prior to it. Its radiant illumination has also been compared to that of comet Vesta, which was discovered in 1976.

Hale Bopp: A Closer Look at the Comet’s Appearance

As per the information provided by NASA, this recently discovered comet appeared to be larger and brighter compared to Halley’s comet. What made it even more remarkable was its twin tails, one blue and the other white, which were visible from the same distance. The presence of these distinct tails made the naked-eye object truly captivating, to the extent that even residents of brightly lit cities like Chicago could witness its beauty with astounding clarity.

Several images were captured of this comet, some of which display its distinct pointed shape caused by the light emitted by the stars in the background. Consequently, in 1996, many individuals referred to it as a celestial body resembling Saturn. There were also speculations surrounding this luminous comet, with certain individuals asserting that it is an enormous spacecraft circling the Earth and is three times the size of our planet. It was observable during a total solar eclipse that transpired during daylight hours in China, Mongolia, and Siberia on March 9, 1997. The visibility of this radiant comet from our planet was documented for a period exceeding a year and a half until 1997.

Hale Bopp: The Make-up and Temperature

The identification of hydrogen cyanide within the Hale-Bopp comet was made in April 1996. This significant finding was obtained through the analysis of images captured by the James Clerk Maxwell Submillimeter Telescope while the sun was still shining.

Comets are essentially icy and dusty spheres that traverse through space at incredible speeds, capable of reaching temperatures as low as 53.1 K (-220 ℃) (-364 ℉). These celestial bodies often enter the gravitational field of planets, propelling themselves towards these planetary bodies with immense velocity. Despite this, comets remain frozen and adrift in the vast expanse of space. The Hale-Bopp comet, for instance, maintained a stable perihelion passage around the Sun for a significant period of time, while also maintaining a sufficient orbital distance to keep it prominently visible in the night sky. This distance ensured that it remained far from the Sun’s twilight glare. Its exceptional luminosity was greatly admired by observers in the northern hemisphere, who were able to witness its nightly splendor. The impact of a collision between comets the size of Hale and Bopp would result in the boiling of oceans and the vaporization of rocks, ultimately leading to the sterilization of Earth’s surface.

Hale Bopp: Characteristics

Hale Bopp displays a vibrant blue ion tail adorned with streaks of white particles. Its luminosity allows it to be easily seen with the naked eye.

These remarkable dual tails of the comet are more visible in the sky compared to any other comet. Its composition primarily consists of ionic gases, ice, and dust. It is currently hurtling through space at a speed of approximately 100,000 miles per hour (around 156,000 km/h). It is presently located at a significant distance from the Sun, near the vicinity of Pluto in the constellation Octantus.

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The Hale-Bopp comet, which first made its appearance in 1995, is one of the most widely-discussed comets.

The constant brilliance of the comet against a backdrop of blue was absolutely captivating, enchanting the hearts of millions. It remained visible to the unaided eye for an impressive duration of over 18 months, setting a new record for its longevity.

The exceptional visibility of the comet without the aid of telescopes is attributed to its remarkable size, boasting a nucleus that spans 37.28 miles (60 km) in width. Its elongated orbital period, currently standing at 2,533 years, earns it the distinction of being a long-term visitor in close proximity to the planets. It is projected to make its return to the inner solar system around the year 4385.

In the year 1997, Comet Hale-Bopp held the distinction of being the most frequently photographed celestial body. It graced the naked eye with its presence from 1995 until the conclusion of 1997, earning the title of the comet with the longest observed lifespan. Its massive nucleus contributes to its extraordinary luminosity, making it a highly visible comet. At the time, it was also the farthest comet ever detected by amateur astronomers.

Hubble Space Telescope images provide a wealth of information about various bright comets, such as Hale Bopp. It has been discovered that this particular comet measures approximately 24.85 miles (40 kilometers) in diameter and has a rotation period of 11.4 hours. Numerous images of Comet Hale-Bopp are accessible, shedding light on its impressive luminosity. In contrast, Comet Encke holds the record for the shortest orbital period among all known comets in our solar system, completing one orbit every three years and three months.

The Discovery of Hale-Bopp

Hale-Bopp Comet was initially detected on July 23, 1995, by two amateur astronomers who independently observed it. These astronomers were Thomas Bopp and Alan Hale from the United States.

It was spotted between the planets Jupiter and Saturn and was approximately 7.2 astronomical units (a.u.) away from the Sun. Astronomers identified it as a sizable comet due to its close proximity to Earth. In the inner solar system, this comet’s orbit was observed at perihelion on April 1, 1997. This comet, with its impressive luminosity, was visible to people worldwide, particularly in the Northern Hemisphere. Some even claim that it appeared so brilliant that it surpassed the size of the previously discovered Halley’s Comet. Its radiant glow has also been likened to that of comet Vesta, which was discovered in 1976.

As per NASA, this recently discovered comet, which was bigger and more luminous than Hale’s comet, could be seen from a similar distance because of its paired blue and white tails. The unique dust trail of this easily observable entity was so remarkable that even inhabitants of brightly lit urban areas, like Chicago, had the astonishing ability to witness it with utmost clarity.

Several images were captured of this comet, some of which display its pointed shape caused by the light emitted by the stars in the background. Consequently, in 1996, numerous individuals referred to it as a Saturn-like entity. There were also speculations surrounding this luminous comet, with certain individuals asserting that it was a colossal spacecraft orbiting Earth and three times the size of our planet. It was even visible during a total solar eclipse that took place during daylight hours in China, Mongolia, and Siberia on March 9, 1997. The visibility of this luminous comet from our planet was documented for over a year and a half until 1997.

Despite the captivating brilliance of this comet, a cult of 40 individuals in San Diego chose to commit mass suicide. They firmly believed that this celestial phenomenon, known as “Heaven’s Gate,” symbolized the end of their existence on Earth and their imminent journey into the cosmos. Marshall Applewhite and Bonnie Nettles, the leaders of this cult, propagated a narrative that they were actually extraterrestrial beings trapped inside human bodies. According to their teachings, they would shed their earthly vessels and return to their true forms upon departing from this world.

Hale Bopp: Composition and temperature

In April 1996, scientists discovered the presence of hydrogen cyanide in the Hale-Bopp comet. This important finding was made using images captured by the James Clerk Maxwell Submillimeter Telescope, even during daylight hours.

Comets are essentially icy and dusty spheres that travel through space at incredible speeds, reaching a freezing point of 53.1 K (-220 ℃) (-364 ℉). They typically enter the gravitational field of planets and then hurtle towards them with immense velocity. However, comets remain frozen and adrift in space. The Hale-Bopp comet’s perihelion passage around the Sun remained stable for a considerable period, and its orbital distance was far enough to keep it visible in the night sky, away from the Sun’s glare. Its exceptional luminosity was greatly admired by observers in the northern hemisphere. A collision the size of Hale and Bopp would release enough energy to cause oceans to boil and rocks to vaporize, resulting in the sterilization of Earth’s surface.

Hale Bopp exhibits a vibrant blue ion tail adorned with streaks of white particles. Its luminescence renders it easily observable to the naked eye.

These splendid dual tails of a comet are more perceptible in the heavens than any other comet. It is predominantly comprised of ionic gases, frozen water, and fine particles. Its velocity is approximately 100,000 miles per hour (almost 156,000 km/h). It currently resides at a considerable distance from the Sun, nearly adjacent to Pluto in the Octantus constellation.