1. Meteorites

2. This meteorite, a basalt lava rock nearly indistinguishable from many Earth rocks, provided the first strong proof that meteorites could come from Mars. Originally weighing nearly 8 kilograms (17.6 pounds), it was collected in 1979 in the Elephant Moraine area of Antarctica. This meteorite fell in 1970 in Cherokee County, Oklahoma. It is subclassed as H Group or an olivine- bronzite chondrite. Meteorites are bits of rock that are captured by a planet's gravity and pulled to the surface. This meteorite is of a type named chondrite and is thought to have formed at the same time as the planets in the solar nebula, about 4.55 billion years ago. (Copyright Calvin J. Hamilton)

3. This is a section from a stone chondrite meteorite that fell in 1852 in Harghita, Romania. (Copyright Calvin J. Hamilton) This meteorite fell in 1924. Notice the depreessions on this sample. These are called regmaglypts and are most likely paralled to the air flow direction during the flight of the meteorite. (Copyright Calvin J. Hamilton)

4. Discovered at Norton County, Kansas, this type of meteorite is known as an achondrite. It has a basaltic 1 composition and was probably formed when an asteroid melted about 4.5 billion years ago. The asteroid broke up some time later and this small piece of the asteroid was captured by Earth's gravity and fell to the ground. (Copyright Calvin J. Hamilton)basaltic 1 A general term for dark-colored, igneous rocks composed of minerals that are relatively rich in iron and magnesium.

5. This iron meteorite was found at Victoria Land, Antarctica. This type of meteorite gets its name because it is mostly made of the elements iron and nickel. This sample is probably a small piece from the core of a large asteroid that broke apart. (Copyright Calvin J. Hamilton)

6. This Iron (III E) Meteorite contains a distinctive crystal pattern known as the Widmanstaten structure. It was fashioned over thousands or millions of years in a low gravity environment at an extremely low rate of cooling producing large crystals of nickel-rich and nickel-poor metallic bands. Such a structure is impossible to forge making the identity of this and similar iron meteorites absolute. Laboratories are only able to imitate it on the microscopic scale. This sample has been cut, polished and etched with acid to enhance the view of the Widmanstaten structure. (Copyright Calvin J. Hamilton)

7. This meteorite was found in 1942. (Copyright Calvin J. Hamilton) Edmonton - Iron (III CD) Meteorite

8. Martian Meteorite This meteorite fell in 1911 in Alexandria, Egypt. It is believed to have formed on Mars based on its dense pyroxene (greenish-gray) and olivine (brown) crystals which are a signature of martian molten rock. It also contains water-bearing minerals. (Copyright Calvin J. Hamilton)

9. Martian Meteorite Slice This meteorite fell in 1962 in Katsina Province, Nigeria. It is believed that it is a fragment of a Martian lava flow. It found its way to Earth when a giant impact on Mars catapulted rock fragments into space. A close look at the black glass veins show they are impact melt that contain Martian gases. (Copyright Calvin J. Hamilton)

10. Peekskill Meteorite This meteorite is famous for the fact that when it fell on October 9, 1992 it destroyed the trunk of a car in Westchester County, New York. (Copyright Calvin J. Hamilton)

11. Stony-iron Meteorite This stony-iron, Pallasite meteorite was found in Atacama, Chile in 1822. (Copyright Calvin J. Hamilton)

12. Stony-iron Meteorite This Stony-iron, pallasite meteorite was found in 1909 in Chihuahua, Mexico. (Copyright Calvin J. Hamilton)

13. Vesta Meteorite This meteorite is assumed to be a sample of the crust of the asteroid Vesta, which is only the third solar system object beyond Earth where scientists have a laboratory sample (the other extraterrestrial samples are from Mars and the Moon). The meteorite is unique because it is made almost entirely of the mineral pyroxene, common in lava flows. The meteorite's mineral grain structure also indicates it was once molten, and its oxygen isotopes are unlike oxygen isotopes found for all other rocks of the Earth and Moon. The meteorite's chemical identity points to the asteroid Vesta because it has the same unique spectral signature of the mineral pyroxene. Most of the identified meteorites from Vesta are in the care of the Western Australian Museum. This 1.4 pound (631 gm) specimen comes from the New England Meteoritical Services. It is a complete specimen measuring 9.6 x 8.1 x 8.7 centimeters (3.7 x 3.1 x 3.4 inches), showing the fusion crust, evidence of the last stage in its journey to Earth. (Photo Credit: R. Kempton, New England Meteoritical Services)Vesta