NASA's WISE Telescope Aims to Identify New Asteroids

A number of objects can be seen in the night sky using only the naked eye and many more can be identified using a simple telescope. Observing the night sky has now been practiced for centuries and as technology has improved our knowledge of the asteroids, planets and stars in our own solar system and beyond has advanced. The latest mission of the National Aeronautics and Space Administration (NASA), the Wide-field Infrared Survey Explorer (WISE) Telescope was launched on 14 December 2009 and is expected to provide a dramatic leap forward in this knowledge.

The WISE Telescope is the latest in a long line of instruments that have been launched into space as part of NASA’s Explorer Missions. The instrument was designed, fabricated and tested by the Space Dynamics Laboratory in Logan, Utah and includes a 16 inch diameter telescope and four infrared detectors.

It has been launched into an orbit 525 kilometers above the Earth and will circle the planet 15 times a day, during which it will capture images of the night sky on an infrared sensitive digital camera. An image will be captured every 11 seconds with each picture covering an area of the sky around 3 times the size of the moon.

The operational phase of the mission is planned to last for 10 months and during the first 6 months of this the telescope will scan and map the entire night sky. Each position in the sky will be mapped at least eight times during this process and following its completion the telescope will begin a second scan which will continue for the remainder of the mission. The second scan will be used to try and identify further objects in the night sky and also to check if any changes have occurred since the first scan.

The mission has a number of objectives which include finding and studying asteroids and comets in our solar system, identifying the nearest and coolest stars which are know as brown dwarfs and to find the most luminous galaxies in the universe. It is expected that the mission will capture the images of hundreds of millions of objects in the night sky and the sensitivity of the infrared equipment is such that it will discover many objects that have previously gone unseen.
The finds that the telescope will make closest to our own planet will be near-Earth objects such as asteroids and comets which have orbits that bring them close to us. It is expected that hundreds of previously undetected dark asteroids will be identified by the mission and this will help in the search for potentially dangerous near-Earth objects which may be on a collision course with our planet.

The mission will also identify most of the asteroids with a size of 3 kilometers or greater in the main asteroid belt of our solar system and by measuring the infrared light from these will provide a good estimate of the size distribution of the asteroid population. Scientists should be able to use this information to make an estimation of how often it is likely that the Earth will have an encounter with a potentially dangerous object. The data collected should also provide an insight into the composition of asteroids and give clues as to whether they are solid or more like giant snowballs. Both the size and composition of an asteroid are important in determining its threat to our planet. The information from the mission will therefore assist future studies of potentially dangerous asteroids and also help in formulating a strategy for any that are found to be heading towards Earth and need to be dealt with.

The WISE Telescope will also be sensitive enough to identify brown dwarfs which form like stars but do not pick up enough mass to ignite nuclear fusion at their cores. It is suspected that around 1000 of these objects lie within 25 light years of planet Earth and the telescope should be able to provide confirmation of this. It has also been speculated that WISE may identify a ninth planet in our own solar system. The pattern of comet orbits around the Sun suggest that there may be a giant gas planet on the outskirts of our solar system about 25,000 times as far from the Sun as planet Earth and if this is the case then WISE should be able to confirm its existence.

Other finds are expected to include millions of energetic galaxies which are known as ultra-luminous infrared galaxies, newborn stars and disks of planetary debris around young stars. The most interesting finds that the WISE Telescope makes will be followed up by other missions including the Hubble Space Telescope, the Spitzer Space Telescope and ground based observatories. Information from the mission will also be used to target interesting areas of the universe by the James Webb Space Telescope when it is launched in 2014.

Data from the mission will be released in two stages. A preliminary release is scheduled for 6 months after completion of the mission and the final release will follow on 11 months after this. The results will be eagerly awaited by the scientific community and hopefully the mission will be a stunning success, providing new and exciting information that will broaden our knowledge of the solar system and universe in which we live.