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Near Space Objects

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Learn about NEOs

• Near-Earth Objects (NEOs) are comets,

meteorids and asteroids that have been nudged by the

gravitational attraction of nearby

planets into orbits that allow them to enter

the Earth's neighborhood.

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Asteroids

• Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets.

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Near Earth Asteroids• Amors cross Mars' orbit but

do not quite cross Earth's orbit. Eros, which was visited by the Near Earth Asteroid Rendezvous (NEAR) spacecraft, is an Amor. More than 1,500 Amors are known.

• Apollos are Earth orbit-crossing asteroids with orbit periods that are longer than one year. Asteroid Geographos is an Apollo.  More than 1,700 Apollos are known.

• Atens cross Earth's orbit with an orbital period less than 1 year. Roughly 300 Atens are known.

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Comets

Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases. They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto.

-In the image you can see the structure of a comet

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Meteorids• A meteoroid is a piece of

stone-like or metal-like debris which travels in outer space. Most meteoroids are no bigger than a pebble.

• If you have ever seen a "falling star", you were actually seeing a meteor. Isn't that amazing?

• Meteoroids burn up in the atmosphere and fall to the Earth as dust. Every day, approximately 3000 metric tons of dusty space material falls to Earth.

• In Greenland, people dig up meteorites and use the iron in them to make tools.

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Meteoroids travel around the sun in a variety of orbits and at various velocities. The fastest ones

move at about 26 miles per second (42 kilometers per second) through space in the vicinity of Earth's

orbit.

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Impacts rate

• The rate of impacts of objects of at least 1 km in diameter is estimated as 2 per million years. Assuming that this rate will continue for the next billion years, there exist at least 2,000 objects of diameter greater than 1 km that will eventually hit Earth

Historic impacts1908

a stony asteroid exploded over Tunguska

2002

On June 6, 2002 an object with an estimated diameter of 10 meters collided with Earth.

2008

This is the first time that an asteroid impact on Earth has been accurately predicted.

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