Clarke had originally intended to write the third book after NASA's Galileo mission to Jupiter had returned its findings in the late 1980s. The probe had been initially scheduled for launch in 1984 but this was delayed, first to 1985 and then to 1986. It was delayed further in wake of the Space Shuttle Challenger disaster. [1] Deciding not to wait, Clarke took inspiration for his sequel from the return of Halley's Comet. Galileo was eventually launched by Space Shuttle Atlantis on the STS-34 mission in October 1989. [2] It arrived in Jovian orbit almost eight years after the publication of 2061: Odyssey Three. Next return with perihelion on 28 July 2061 [4] [5] and Earth approach one day later on 29 July 2061 [7]

Although the comet's retrograde orbit and high inclination made it difficult to send a space probe to it, [124] the 1986 apparition gave scientists the opportunity to study the comet closely and several probes were launched to do so. The Soviet Vega 1 probe began returning images of Halley on 4 March 1986, captured the first-ever image of its nucleus, [18] and made its flyby on 6 March. It was followed by the Vega 2 probe, making its flyby on 9 March. On 14 March, the Giotto space probe, launched by the European Space Agency, made the closest pass of the comet's nucleus. [18] There also were two Japanese probes, Suisei and Sakigake. Unofficially, the numerous probes became known as the Halley Armada. [125]Depicted on the Eadwine Psalter, with the remark that such "hairy stars" appeared rarely, "and then as a portent". It soon becomes evident that the landing was not an accident at all, but a planned mission aimed at discovering the nature of a stupendous mountain that had appeared suddenly on Europa’s cloud-shrouded surface, in defiance of all laws of geological evolution--a secret that turns out to be literally shattering. With the revival of hard scifi space film genre with Gravity, Interstellar and The Martian both critically and financially after the disastrous flop that was Mission to Mars, I think this would be a good time to do another Odyssey film. The 374AD and 607 approaches each came within 0.09 au of Earth. [65] The 451AD apparition was said to herald the defeat of Attila the Hun at the Battle of Chalons. [72] The 684AD apparition was recorded in Europe in one of the sources used by the compiler of the 1493 Nuremberg Chronicles, which contains an image 8 centuries after the event. [73] Chinese records also report it as the "broom star". [74] [26] In 837, Halley's Comet may have passed as close as 0.03au (3.2million miles; 5.1million kilometres) from Earth, by far its closest approach. [75] [65] Its tail may have stretched 60 degrees across the sky. It was recorded by astronomers in China, Japan, Germany, the Byzantine Empire, and the Middle East; [64] Emperor Louis the Pious observed this appearance and devoted himself to prayer and penance, fearing that "by this token a change in the realm and the death of a prince are made known." [76] In 912, Halley is recorded in the Annals of Ulster, which state "A dark and rainy year. A comet appeared." [77] 1066 [ edit ] Halley's Comet in 1066 depicted in the Bayeux Tapestry Halley's Comet seen from London on 6 May 1066 as simulated by Stellarium. The Moon, Mars, Jupiter, and Saturn are also visible. a b c Lynn, W. T. (1909). "Halley's Comet i

While it will be decades before we can send another spacecraft to Halley's Comet, there have several other missions that have studied comets from up close. Between 2014 and 2016, for example, the Rosetta probe examined Comet 67P/Churyumov–Gerasimenko up close and made comparisons to other comets.O'Toole, Thomas (1985). "A Comet Lights the Imagination". The New York Times . Retrieved 13 September 2018.

Margeret M'Bala: An author who popularized and explained the connections between ancient Greek and Roman mythology and now-common astronomical nomenclature, "Maggie M" is another of the celebrity passengers.Famous astronomers across the world made observations starting August 1835, including Struve at Dorpat observatory, and Sir John Herschel, who made of observations from the Cape of Good Hope. [96] In the United States telescopic observations were made from Yale College. [96] The new observations helped confirm early appearances of this comet including its 1456 and 1378 apparitions. [96] Ridpath, Ian (1985). "Saying Hallo to Halley". Revised extracts from "A Comet Called Halley" by Ian Ridpath, published by Cambridge University Press in 1985 . Retrieved 8 May 2015. Astrophotography was not known to have been attempted until 1839, as photography was still being invented in the 1830s, too late to photograph the apparition of 1P/Halley in 1835. [98] The comet's pass in 1910 was particularly spectacular, as the comet flew by about 13.9 million miles (22.4 million kilometers) from Earth, which is about one-fifteenth the distance between Earth and the sun. On that occasion, Halley's Comet was captured on camera for the first time. There is a group of comets called "Halley family comets" (HFC) because they appear to share the same orbital characteristics of Halley, including being highly inclined to the orbits of Earth and other planets in the solar system. However, this family has a range of inclinations, which prompts other astronomers to suggest they may have a different origin than Halley.

May be the comet described in Josephus's The Jewish War as "A comet of the kind called Xiphias, because their tails appear to represent the blade of a sword" that supposedly heralded the destruction of the Second Temple in 70 AD. [66] Halley may have been recorded as early as 467BC, but this is uncertain. A comet was recorded in ancient Greece between 468 and 466 BC; its timing, location, duration, and associated meteor shower all suggest it was Halley. [58] According to Pliny the Elder, that same year a meteorite fell in the town of Aegospotami, in Thrace. He described it as brown in colour and the size of a wagon load. [59] Chinese chroniclers also mention a comet in that year. [60] Report of Halley's Comet by Chinese astronomers in 240 BC ( Shiji)a b c d e f "Horizons Batch for 1P/Halley (90000030) on 2061-Jul-28" (Perihelion occurs when rdot flips from negative to positive @ 2061-Jul-28 17:20 UT). JPL Horizons. Archived from the original on 27 May 2022 . Retrieved 28 June 2022. (JPL#73 Soln.date: 2022-Jun-07) I came in with Halley's comet in 1835. It is coming again next year, and I expect to go out with it. It will be the greatest disappointment of my life if I don't go out with Halley's comet. The Almighty has said, no doubt: 'Now here are these two unaccountable freaks; they came in together, they must go out together.' [111] [112] In what situations are "environmentalists" involved? Are their activities and demands constructive or pertinent in the story? Why or why not? In a new study, we produced a range of population projections for the UK to the year 2061, based on assumptions about what would happen to international migration under three Brexit scenarios: no Brexit, a soft Brexit and a hard Brexit. Photo: Phil Dolby via a CC BY 2.0 licence Ross, Marvin (30 July 1981). "The ice layer in Uranus and Neptune—diamonds in the sky?". Nature. 292 (5822): 435–436. Bibcode: 1981Natur.292..435R. doi: 10.1038/292435a0. S2CID 4368476.