Pan-STARRS and the NEO Threat


The Lincoln Near Earth Asteroid Research (LINEAR) project, the Lowell Near Earth Object Search (LONEOS), the Near-Earth Asteroid Tracking (NEAT) project, and the Spacewatch program have discovered many thousands of main-belt asteroids and identified almost 2,000 NEOs. These pioneering surveys have made great progress toward meeting the Congressional mandate. The 1-km sized and larger NEOs are believed to be those most likely to produce a global catastrophy, such as a mass extinction -- including humans, should they collide with Earth. There is still some uncertainty in the astronomical community as to the number of these dangerous NEOs that are present in the solar system.

Pan-STARRS is designed to be the next level of advancement in NEO survey work. This new system will have 3-16 times the collecting power of the current NEO survey telescopes and a massive array of state-of-the-art CCD detectors in the focal plane. This will enable the Pan-STARRS survey to reach about 5 magnitudes (a factor of 100) fainter objects than are currently observed by the NEO surveys. Further, Pan-STARRS' large field of view (7 deg2 per exposure) is larger than that of any of the current NEO survey programs. This will allow us to observe the available sky faster and more frequently than any of the current programs. Finally, Pan-STARRS will have higher spatial resolution than the existing survey systems, allowing us to work in the parts of the sky where the ecliptic plane overlaps with the Milky Way, often too crowded with stars for the current surveys to observe effectively.

The Pan-STARRS system consists of more than just the telescopes and CCD cameras. Backing up the observing equipment will be a powerful computing environment that will process the observations, calibrate the astrometric and photometric (position and brightness) properties of individual observations, and detect the "moving" objects such as asteroids, comets, and Trans-neptunian objects (TNOs). The system will also track all objects already known (or discovered by itself), so that on future nights when an object is reobserved it can be rapidly identified and if necessary, its orbit updated to include the new data. There are currently about 100,000 known moving objects in our solar system that are tracked by professional astronomers. With Pan-STARRS, we estimate that we will catalog up to 10 million main-belt asteroids and tens of thousands of NEOs and TNOs.

By reaching objects 100 times fainter than those currently observed in the NEO surveys, Pan-STARRS should quickly help finish off the Congressional mandate to find and determine orbits for the 1-km (and larger) threatening NEOs. Further, we will  be able to push the detection limit for a complete (99%) sample down to objects as small as 300-meters in diameter. Such objects, while not capable of wiping out life on Earth, would cause considerable local and/or regional damage should one collide with our planet.