Small bodies:Comets,Meters,Astroids
By Garrette Yow
Meteors
METEOR,
in astronomy, small solid body entering a planet's atmosphere from outer space and raised to incandescence by the friction resulting from its rapid motion. Brilliant meteors, known as fireballs, occur singly and generally consist of a luminous head, followed by a comet like train of light that may persist for several minutes; some, called bolides, have been seen to explode with a sound like thunder. Fainter meteors, called shooting or falling stars, usually occur singly and sporadically. At intervals, however, hundreds of such meteors occur simultaneously and appear to emanate from a fixed point. These swarms are called meteoric showers and are named after the constellation in which they seem to have their point of origin. Some appear annually on the same days of each year and are called periodic showers; others occur infrequently at varying intervals. The periods of meteoric showers generally coincide with those of certain comets. Most meteors are dissipated in flight and fall to the earth as dust; a meteor that reaches the surface of the earth or another planet is called a METEORITE. They may hold gems or metals.meteor shower dates
Quadrantids
Quadrantids is the first meteor shower of every year, usually occurring between the last week of December, and January 12. It peaks around January 3 and January 4, and is best seen from the Northern Hemisphere. The radiant point for the Quandrantids lies in the constellation Boötes, close to the Big Dipper.
Lyrids
The radiant point of the Lyrids lie in the constellation Lyra. This meteor shower occurs between April 16 to April 26th of every year and can seen from the Northern and Southern Hemisphere.
Eta Aquarids
The next major meteor shower of year, the Eta Aquarids, occurs between late April and mid May, peaking around May 5-6. It is best seen from the Southern Hemisphere, though observers in the Northern Hemisphere can also enjoy a sparser display. Meteoroids in the Eta Aquarids are actually remnants from Halley’s Comet. The radiant for this shower lies in the constellation Aquarius.
Perseids
The Perseid meteor shower occurs in mid August, reaching peak activity around August 11-13. Its radiant lies in the constellation Perseus, and is associated with the comet Swift-Tuttle.
Draconids
The Draconid meteor shower, occurs every October, peaking around October 7-8. The name of this shower comes from the constellation Draco the Dragon.
Orionids
The Orionid meteor shower, which is also associated with debris from Halley’s comet, occurs every October, peaking around October 21-22. The name of this shower comes from the constellation Orion.
Leonids
Leonids occur during the month of November, usually peaking around mid-November. It is associated with the comet Tempel-Tuttle and is named after the constellation, Leo.
Geminids and Ursids
The month of December is good for meteor shower watchers, with the Geminids gracing the skies in early December, peaking around December 13-14, and the Ursids that peak around December 22-23. The Geminids owes its name to the constellation Gemini and are the only major meteor shower that is not associated with a comet, but with an asteroid. Ursids on the other hand get their name from the constellation Ursa Minor.
Comets
comets
Halley's Comet
Halley's Comet
Halley's Comet or Comet Halley officially designated is a short-period comet visible from Earth every 75–76 years. Halley is the only known short-period comet that is clearly visible to the naked eye from Earth, and the only naked-eye comet that might appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.
Halley's returns to the inner Solar System have been observed and recorded by astronomers since at least 240 BC. The comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named.
During its 1986 apparition, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation. These observations supported a number of longstanding hypotheses about comet construction, particularly Fred Whipple's "dirty snowball" model, which correctly predicted that Halley would be composed of a mixture of volatile ices – such as water, carbon dioxide, and ammonia – and dust. Halley is largely composed of dusty, non-volatile materials, and that only a small portion of it is icy. Halley's Comet is said to be the most amazing comet to ever be seen.
Halley's Comet
Other Comets
Asteroids
Asteroid
Asteroids are minor planets, especially those of the inner solar system . The larger ones have also been called Planetoids. These terms have historically been applied to any astronomical object orbiting the Sun that did not show the disc of a planet and was not observed to have the characteristics of an active comet. As minor planets in the outer Solar System were discovered and found to have volatile-based surfaces that resemble those of comets, they were often distinguished from asteroids of the asteroid belt. In this article, the term "asteroid" refers to the minor planets of the inner Solar System including those in co-orbit with Jupiter.
There are millions of asteroids, many thought to be the shattered remnants of planetesimals, bodies within the young Sun's solar nebula that never grew large enough to become planets. The large majority of known asteroids orbit in the asteroid belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter (the Jupiter trojans). However, other orbital families exist with significant populations, including the near-Earth asteroids. Individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups: C-type, M-type, and S-type. These were named after and are generally identified with carbon-rich, metallic, and silicate (stony) compositions, respectively.