The European Space Agency's Gaia has just passed its first year anniversary of observing stars in main survey mode last Aug. 21.
The star surveyor was launched Dec. 19, 2013, going on a six-month journey to reach its destination more than 932,000 miles away from Earth at the Lagrange point L2. On July 25, 2014, Gaia started routine scientific operations. After 28 days of sampling great circles in the sky with ecliptic poles, it commenced main survey operation, utilizing a scanning algorithm developed to cover the sky at the best possible quality.
Since Aug. 21, 2014, Gaia has recorded 272 billion astrometric or positional measurements, 54.4 billion photometric or brightness points and 5.4 billion spectra. The satellite's project team has been busily spending the year analyzing and processing data to make way for developing main scientific products for Gaia. Due to the immense volume of data and the complex nature of the information, software developers and expert scientists from all over Europe have pitched in to create the Data Processing and Analysis Consortium.
"We are just a year away from Gaia's first scheduled data release," shared Timo Prusti, a project scientist for GAIA with the ESA.
With a first year's worth of data, Gaia scientists are halfway towards this milestone. They are actually already able to present some preliminary snapshots from the star surveyor, showing the spacecraft is functioning as it should and the processing of data is moving along as intended.
One proof that Gaia is fully functional is that it has been taking parallax measurements for two million stars. The parallax is a star's apparent motion against a background from a distance that is observed for one year. The larger the parallax is, the nearer a star's location is to the sun. However, the parallax is not the only movement that the spacecraft detects.
Using its initial sample of stars, Gaia has taken around 14 measurements of each. This didn't yield enough information though so data is being combined with what the Hipparcos satellite gathered from 1989 to 1993.
As Gaia repeatedly scans the sky to measure the stars' motion, it has observed changes in brightness in many of the stars, giving rise to discoveries of some very interesting objects in space.
