The Geminids are a prolific meteor shower caused by the object 3200 Phaethon, which is thought to be a Palladian asteroid with a "rock comet" orbit. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet. The meteors from this shower are slow moving, can be seen in December and usually peak around December 4–16, with the date of highest intensity being the morning of December 14. The shower is thought to be intensifying every year and recent showers have seen 120–160 meteors per hour under optimal conditions, generally around 02:00 to 03:00 local time. Geminids were first observed in 1862, much more recently than other showers such as the Perseids and Leonids.
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.
The Quadrantids (QUA) are a meteor shower that peaks in early January and whose radiant lies in the constellation Boötes. The zenithal hourly rate (ZHR) of this shower can be as high as that of two other reliably rich meteor showers, the Perseids in August and the Geminids in December, yet Quadrantid meteors are not seen as often as those of the two other showers because the time frame of the peak is exceedingly narrow, sometimes lasting only hours. Moreover, the meteors are quite faint, with mean apparent magnitudes between 3.0 and 6.0.
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 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. 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.
1566 Icarus is a large near-Earth object of the Apollo group and the lowest numbered potentially hazardous asteroid. It has is an extremely eccentric orbit (0.83) and measures approximately 1.4 km (0.87 mi) in diameter. In 1968, it became the first asteroid ever observed by radar. Its orbit brings it closer to the Sun than Mercury and further out than the orbit of Mars, which also makes it a Mercury-, Venus-, and Mars-crossing asteroid. This stony asteroid and relatively fast rotator with a period of 2.27 hours was discovered on 27 June 1949, by German astronomer Walter Baade at the Palomar Observatory in California. It was named after the mythological Icarus.
3200 Phaethon, provisional designation 1983 TB, is an active Apollo asteroid with an orbit that brings it closer to the Sun than any other named asteroid. For this reason, it was named after the Greek myth of Phaëthon, son of the sun god Helios. It is 5.8 km (3.6 mi) in diameter and is the parent body of the Geminids meteor shower of mid-December. With an observation arc of 35+ years, it has a very well determined orbit. The 2017 Earth approach distance of about 10 million km was known with an accuracy of ±700 m.
A sungrazing comet is a comet that passes extremely close to the Sun at perihelion – sometimes within a few thousand kilometres of the Sun's surface. Although small sungrazers can completely evaporate during such a close approach to the Sun, larger sungrazers can survive many perihelion passages. However, the strong evaporation and tidal forces they experience often lead to their fragmentation.
The Kreutz sungrazers are a family of sungrazing comets, characterized by orbits taking them extremely close to the Sun at perihelion. They are believed to be fragments of one large comet that broke up several centuries ago and are named for German astronomer Heinrich Kreutz, who first demonstrated that they were related. A Kreutz sungrazer's aphelion is about 170 AU from the Sun; these sungrazers make their way from the distant outer Solar System from a patch in the sky in Canis Major, to the inner Solar System, to their perihelion point near the Sun, and then leave the inner Solar System in their return trip to their aphelion.
Comet Ikeya–Zhang is a comet discovered independently by two astronomers from Japan and China in 2002. It has by far the longest orbital period of the numbered periodic comets.
73P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 3, is a periodic comet that has a 5.4 year orbital period and that has been actively disintegrating since 1995. It last came to perihelion in March 2017 when fragment 73P-BT was separating from the main fragment 73P-C. Fragments 73P-BU and 73P-BV were detected in July 2022. The main comet came to perihelion on 25 August 2022 The comet was 0.97 AU from the Sun and 1 AU from Earth. It will be less than 80 degrees from the Sun from 25 May 2022 until August 2023.
Comet C/1861 G1 (Thatcher) is a long-period comet with roughly a 415-year orbit that is expected to return around 2283. It was discovered by A. E. Thatcher. It is responsible for the April Lyrid meteor shower. Carl Wilhelm Baeker also independently found this comet. The comet passed about 0.335 AU from the Earth on 1861-May-05 and last came to perihelion on 1861-Jun-03.
Alpha Capricornids is a meteor shower that takes place as early as 7 July and continues until around 15 August. The meteor shower was discovered by Hungarian astronomer Miklos von Konkoly-Thege in 1871. This shower has infrequent but relatively bright meteors, with some fireballs. Parent body is comet 169P/NEAT.
332P/Ikeya–Murakami is a short-period comet with period of approximately 5.4 years first identified independently by the two Japanese amateur astronomers Kaoru Ikeya and Shigeki Murakami on November 3, 2010. Ikeya identified the comet using a 25-centimeter (10-inch) reflector at 39×, while Murakami used a 46 cm (18-inch) reflector at 78×. Photographic confirmation of the comet was obtained by Ernesto Guido and Giovanni Sostero using a Global-Rent-a-Scope (GRAS) telescope in New Mexico. Both Ikeya and Murakami discovered the comet using manual observation through optical telescopes. Such visual discoveries have become rare in recent years.
(196256) 2003 EH1 is an asteroid, classified as near-Earth object of the Amor group. It was discovered on 6 March 2003, by astronomers of the LONEOS program at Anderson Mesa Station near Flagstaff, Arizona, in the United States. Peter Jenniskens (2003–2004) proposed that it is the parent body of the Quadrantid meteor shower. 2003 EH1 is likely an extinct comet and may even be related to the comet C/1490 Y1. 2003 EH1 came to perihelion on 12 March 2014.
(155140) 2005 UD is an asteroid on an eccentric orbit, classified as a near-Earth object of the Apollo group. It was discovered on 22 October 2005, by the Catalina Sky Survey at the Catalina Station in Arizona, United States. 2005 UD is thought to be a possible fragment of 3200 Phaethon due to its similar orbit, although it is not dynamically associated with the Geminid meteor stream produced by Phaethon.
C/1962 C1 (Seki–Lines), also known as Comet Seki–Lines and 1962c, was a non-periodic comet discovered indepently by Richard D. Lines and Tsutomu Seki on 4 February 1962. The comet became very bright in April 1962, as passed its perihelion on 1 April at a distance of 0.031 AU.
C/1963 A1 (Ikeya), also known as Comet 1963I and 1963a, is a long period comet discovered by Kaoru Ikeya on 2 January 1963. The comet last passed perihelion on 21 March 1963, when it reached an apparent magnitude of 2.8.
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.
