Comet Hale–Bopp is a comet that was one of the most widely observed of the 20th century and one of the brightest seen for many decades.
Comet Hyakutake is a comet discovered on 31 January 1996. It was dubbed the Great Comet of 1996; its passage to within 0.1 AU (15 Gm) of the Earth on 25 March was one of the closest cometary approaches of the previous 200 years. Reaching an apparent visual magnitude of zero and spanning nearly 80°, Hyakutake appeared very bright in the night sky and was widely seen around the world. The comet temporarily upstaged the much anticipated Comet Hale–Bopp, which was approaching the inner Solar System at the time.
A meteor shower is a celestial event in which a number of meteors are observed to radiate, or originate, from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories. Most meteors are smaller than a grain of sand, so almost all of them disintegrate and never hit the Earth's surface. Very intense or unusual meteor showers are known as meteor outbursts and meteor storms, which produce at least 1,000 meteors an hour, most notably from the Leonids. The Meteor Data Centre lists over 900 suspected meteor showers of which about 100 are well established. Several organizations point to viewing opportunities on the Internet. NASA maintains a daily map of active meteor showers.
Comet Ikeya–Seki, formally designated C/1965 S1, 1965 VIII, and 1965f, was a long-period comet discovered independently by Kaoru Ikeya and Tsutomu Seki. First observed as a faint telescopic object on September 18, 1965, the first calculations of its orbit suggested that on October 21, it would pass just 450,000 km (280,000 mi) above the Sun's surface, and would probably become extremely bright.
Comet Encke, or Encke's Comet, is a periodic comet that completes an orbit of the Sun once every 3.3 years. Encke was first recorded by Pierre Méchain on 17 January 1786, but it was not recognized as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke. Like Halley's Comet, it is unusual in its being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light its nucleus receives, although comets generate a large coma and tail that can make them much more visible during their perihelion. The diameter of the nucleus of Encke's Comet is 4.8 km.
12P/Pons–Brooks is a periodic comet with an orbital period of 71 years. It fits the classical definition of a Halley-type comet with an orbital period between 20 and 200 years, and is also one of the brightest known periodic comets, reaching an absolute visual magnitude ~5 in its approach to perihelion. Comet Pons-Brooks was discovered at Marseilles Observatory in July 1812 by Jean-Louis Pons, and then later recovered in 1883 by William Robert Brooks.
3728 IRAS, provisional designation 1983 QF, is a stony asteroid from the middle region of the asteroid belt, approximately 20 kilometers in diameter. On 23 August 1983, it was discovered by and later named after IRAS, a spaceborne all-sky infrared survey satellite.
Comet Holmes is a periodic comet in the Solar System, discovered by the British amateur astronomer Edwin Holmes on November 6, 1892. Although normally a very faint object, Holmes became notable during its October 2007 return when it temporarily brightened by a factor of a million, in what was the largest known outburst by a comet, and became visible to the naked eye. It also briefly became the largest object in the Solar System, as its coma expanded to a diameter greater than that of the Sun. Between 1857–2106 perihelion remains between 2.05–2.36 AU.
20D/Westphal was a periodic comet with an orbital period of 61 years. It fits the classical definition of a Halley-type comet. The comet appeared to disintergrate during the 1913 apparition and hasn't been observed since then.
Comet Schaumasse is a periodic comet discovered by Alexandre Schaumasse on 1 December 1911 as 12th magnitude. It next comes to perihelion on 8 January 2026 and should brighten to about magnitude 9.
C/1989 X1 (Austin) was a comet discovered by New Zealand amateur Rodney R. D. Austin on December 6, 1989. The comet at discovery was predicted to become easily visible by naked eye in spring 1990, however it failed to become that bright.
Comet 252P/LINEAR is a periodic comet and near-Earth object discovered by the LINEAR survey on April 7, 2000. The comet is a Jupiter family comet, meaning that it passes quite close to the orbit of Jupiter.
108P/Ciffréo is a periodic comet with an orbital period of 7 years discovered by Jacqueline Ciffréo on November 8, 1985. The comet is noted for having a peculiar double morphology, in which the nucleus is accompanied by a comoving, detached, diffuse tail, which is probably a perspective artifact of particles ejected sunwards and then repelled by solar wind.
156P/Russell–LINEAR is a Jupiter family periodic comet with an orbital period of 6.4 years. It was discovered by Kenneth S. Russell in September 1986.
210P/Christensen is a Jupiter family periodic comet with an orbital period of 5.7 years. It was discovered by Eric J. Christensen on 26 May 2003 in images taken by the Catalina Sky Survey and recovered in images obtained by STEREO, the first time a single-apparition comet was recovered by a spacecraft.
Comet Kohoutek is a comet that passed close to the Sun towards the end of 1973. Early predictions of the comet's peak brightness suggested that it had the potential to become one of the brightest comets of the 20th century, capturing the attention of the wider public and the press and earning the comet the moniker of "Comet of the Century". Although Kohoutek became rather bright, the comet was ultimately far dimmer than the optimistic projections: its apparent magnitude peaked at only –3 and it was visible for only a short period, quickly dimming below naked-eye visibility by the end of January 1974.
C/1979 Y1 (Bradfield), also known as Comet 1979X and 1979l, is a long period comet discovered by William A. Bradfield on 24 December 1979. The comet has an orbital period of 308 ± 6 years and last passed perihelion on 21 December 1979. It is considered to be the parent body of the July Pegasids meteor shower. It is expected to next come to perihelion around 2287.
C/1990 K1 (Levy) is a non-periodic comet discovered by David H. Levy on 20 May 1990. The comet became bright enough to be visible by naked eye.
C/1989 W1 (Aarseth–Brewington) is a non-periodic comet discovered on 16 November 1989 independently by Knut Aarseth and Howard Brewington. It reached an apparent magnitude of 2.8.
C/2001 A2 (LINEAR) is a non-periodic comet from the Oort cloud discovered by LINEAR on 15 January 2001. The nucleus of comet split in multible fragments during its perihelion passage. The comet brightened to an apparent magnitude of about 3.
