Here are a few examples of asteroids that humans have observed (Gaspra, Ida, and Dactyl). Gaspra is Astroid 951. Gaspra was another small asteroid that was giving a little attention until it was discovered by Grigoriry N. Neujamin in 1916, that the trajectory of the Galileo spacecraft would take it close to Gaspra. Gaspra was found to have an irregular shape with a rotational period of 7.04 hours, and lack of any large craters suggest that it has a comparatively recent origin, most likely from the collisional breakup of a larger body.
Ida is the 23rd asteroid to be discovered. Its shape is irregular and is in the main asteroid belt between Mars and Jupiter. Ida has the dimensions of 56 by 24 by 21 kilometers. Ida itself is very heavily cratered. It has a period of rotation of four hours and thirty-eight minutes.
Castalia is another one of Earth crossing asteroids. It was discovered on August 9, 1989. Castalia is a dumbbell shape. It is an asteroid of remarkable features. The width is 1.8 kilometers and has two noticeable lobes. The lobes were once separate objects that joined after collision.
Toutatis, first known as asteroid 4179, was discovered by French astronomers in 1989. It was named after a Celtic god of an ancient tribe in Gual. Its four-year orbit extends from the main asteroid belt to just inside the Earth's orbit and is the closet of the other asteroids that crosses earth's orbit. In 1992, Toutatis passed Earth by only four million kilometers. It is projected that on September 29, 2009, Toutatis will pass Earth again but its trajectory (orbit) can not be predicted accurately.
Asteroids in general are a result of left over material from the formation of the solar system. Much of what the world's understanding about asteroids comes from examining pieces of space debris that fall to the surface of Earth. "Asteroids that are on a collision course with Earth are called meteoroids. When a meteoroid strikes our atmosphere at a high velocity, friction causes the chunk of "space matter" to incinerate in a streak of light known as a meteor. If the meteoroid does not burn up completely, what is left strikes the Earth's surface and is called a meteorite. Of all the meteorites examined 92.8 percent are composed of silicate (stone) and 5.7 percent are composed of iron and nickel; the rest are a mix of the 3 (silicate, iron, nickel).
| Number | Name | Radius (km) | Distance* (10^6 km) | Albedo | Discoverer | Date |
|---|---|---|---|---|---|---|
| 1 | Ceres | 457 | 413.9 | 0.10 | G. Piazzi | 1801 |
| 511 | Davida | 168 | 475.4 | 0.05 | R. Dugan | 1903 |
| 15 | Eunomia | 136 | 395.5 | 0.19 | De Gasparis | 1851 |
| 52 | Europa | 156 | 463.3 | 0.06 | Goldschmidt | 1858 |
| 10 | Hygiea | 215 | 470.3 | 0.08 | De Gasparis | 1849 |
| 704 | Interamnia | 167 | 458.1 | 0.06 | V. Cerulli | 1910 |
| 2 | Pallas | 261 | 414.5 | 0.14 | H. Olbers | 1802 |
| 16 | Psyche | 132 | 437.1 | 0.10 | De Gasparis | 1852 |
| 87 | Sylvia | 136 | 521.5 | 0.04 | N. Pogson | 1866 |
| 4 | Vesta | 262.5 | 353.4 | 0.38 | H. Olbers | 1807 |
| 951 | Gaspra | 17 x 10 | 205.0 | 0.20 | Neujmin | 1916 |
| 243 | Ida | 58 x 23 | 270.0 | ? | J. Palisa | 1884 |
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Jason Alfred: I am 16 years old. I'm from Trinidad, and I go to Coconut Creek High School. I am in the 11th grade and I love to party. I love all the fine,sexy women that go to CREEK and other fine public schools in Broward county. |
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Beatrice Benjamin: I'm from the Caribbean Island.I go to ELY HIGH, and I am in the 12th grade. |
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Kurt Tuckett ELY HIGH |