NASA’S NEOWISE finds previously unknown 20 comets, 33,000 asteroids

Wednesday, February 2, 2011

WASHINGTON - NASA has completed its mission of surveying the solar system and has discovered previously unknown objects, including 20 new comets and more than 33,000 asteroids in the main belt between Mars and Jupiter.

The mission, called NEOWISE, also identified 134 near-Earth objects (NEOs) - the NEOs are asteroids and comets whose orbits come within 28 million miles of Earth’s path around the Sun, according to a NASA release.

NEOWISE is an enhancement of the Wide-field Infrared Survey Explorer (WISE) that was launched in December 2009.

Its main purpose was to hunt for more asteroids and comets, and to finish one complete scan of the main asteroid belt.

“Even just one year of observations from the NEOWISE project has significantly increased our catalogue of data on NEOs and the other small bodies of the solar systems,” said Lindley Johnson, NASA program executive for the NEO Observation Program.

In addition to discovering new asteroids and comets, NEOWISE also confirmed the presence of objects in the main asteroid belt that already had been detected.

In just one year, it observed about 153,000 rocky bodies out of approximately 500,000 known objects. Those include the 33,000 that NEOWISE discovered.

The mission also observed known objects closer and farther to us than the main belt, including roughly 2,000 asteroids that orbit along with Jupiter, hundreds of NEOs and more than 100 comets.

These observations will be key to determining the objects’ sizes and compositions.

Visible-light data alone reveals how much sunlight reflects off an asteroid, whereas infrared data is much more directly related to the object’s size.

NEOWISE took longer to survey the whole asteroid belt than WISE took to scan the entire sky because most of the asteroids are moving in the same direction around the Sun as the spacecraft moves while it orbits the Earth.

The spacecraft field of view had to catch up to and lap the movement of the asteroids in order to see them all.

The NEOWISE data are catalogued at the NASA-funded International Astronomical Union’s Minor Planet Center.

The team is now analysing the infrared observations and will publish the new findings in the coming months.

When combined with WISE observations, NEOWISE data will aid in the discovery of the closest dim stars, called brown dwarfs.

The first batch of observations from the WISE mission will be available to the public and astronomical community in April. (ANI)

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