The European Space Agency’s Gaia Space Observatory is a daring project. It has to develop a 3D map of Milky Way by making high-precision measurements of over one billion stars.
However, on its trip to map distant cosmic features, the space observatory improves a field much closer to home – tracking down the lost asteroids. Here are all the details that you should know.
Gaia Uses Stars to Discover Asteroids
Gaia maps our galaxy by repeatedly scanning the whole sky. Throughout its established mission, it spotted each of its more than one billion target stars approximately 70 times to examine how their brightness and position vary over time.
The stars are so distant that their movements between images are tiny. Hence, the space observatory has to evaluate their positions so precisely even to spot a difference. Sometimes, Gaia sees faint light sources that move considerably from one image of a particular area of the sky to the next.
By verifying the locations of those cosmic features against the catalogs of known Solar System objects, many of those turn out to be known asteroids. However, some are classified as potentially new detections and are then recognized by the astronomy community through the Gaia Follow-Up Network for Solar System Objects. Through this process, Gaia has succeeded in spotting new asteroids.
Nothing Gets Lost
Those direct asteroid observations are significant for scientists. However, Gaia’s highly precise evaluations of the positions of stars offer an even more significant, but indirect, benefit for asteroid tracking. Marco Micheli, from ESA’s Near-Earth Object Coordination Center, detailed: “This means that the more accurately we know the positions of the stars, the more reliably we can determine the orbit of an asteroid passing in front of them.”
Teaming up with the European Southern Observatory (ESO), Marco’s team was part of an observation mission targeting 2012 TC4, a tiny asteroid that was due to pass by Earth. But, since the space object was first seen in 2012, it had become fainter as it receded from our planet, eventually turning into an unobservable point. For Gaia, however, the mission wasn’t over.
“We pointed the telescope towards the predicted area of the sky using the data from Gaia, and we found the asteroid on our first attempt,” explained Marco.
More results from Gaia’s mission should be published soon. The space observatory’s work proved to be so useful for scientists that we should await only the best results.