WISE Spacecraft Seeks Near Earth Objects

Stars Using Infrared Wavelengths

NASA committed $320M to the WISE project

Near-Earth Objects (NEOs) represent an extinction level threat to the entire human race. The odds are extremely low that an undetected asteroid or comet will strike the Earth and cause catastrophic damage, but given a long enough period of time anything can happen. It has been hypothesized that a large asteroid impacted the Earth 65 million years ago and led to the mass extinction of the dinosaurs.

NEOs with diameters of less than 10m are typically destroyed in the upper atmosphere, but 50m NEOs can cause massive damage like the Tunguska Event in 1908. A 1km sized NEO is projected to strike the Earth every 500,000 years, while NEOs larger than 5km hit every ten million years.

The possibility of global devastation galvanized the U.S. Congress into action in 2005, mandating NASA to detect 90% of the NEOs ranging from 140m and above by 2020. There are an estimated 20,000 asteroids and comets that have orbits close to Earth, and only 6000 of them have been found so far.

The problem is that many asteroids and comets don't reflect a lot of light, making them hard to detect using conventional telescopes. NASA plans to address this with the Wide-field Infrared Survey Explorer (WISE), which will scan the entire sky in infrared light. Asteroids and comets emit infrared energy, and WISE is not only expected to detect thousands of them, but also provide data on their size, shape, and composition.

WISE is designed to detect the infrared glow of hundreds of millions of objects besides asteroids and comets. It will detect new galaxies, stars, and brown dwarfs, creating a vast catalog of millions of images. These will be used to find new targets for the Spitzer Space Telescope and the Herschel Space Observatory, two other observation missions which focus on specific infrared objects for study.