Space telescope Gaia sent into 'retirement' but legacy endures

INA-sources

Europe's Gaia space telescope was powered down and sent into "retirement" on Thursday after a decade revealing the secrets of the Milky Way, but its observations will fuel discoveries for decades to come.

Since launching in 2013, the telescope has been charting the positions, motion and properties of nearly two billion stars to create an unparalleled map of our home galaxy, according to the European Space Agency.

Gaia has been peering into the universe from a stable orbit 1.5 million kilometres (930,000 miles) from Earth called the second Lagrange point.

But the neighbourhood has been getting more crowded with the recent arrivals of the powerful James Webb and Euclid space telescopes.

To avoid causing any problems for the new kids on the block, the ESA's team on the ground ordered Gaia's engines to give a final push on Thursday that will take the spacecraft into a distant orbit around the Sun.

This "retirement orbit" will make sure the spacecraft will remain at least 10 million kilometres from Earth for the next century.

Over nearly 11 years, Gaia has uncovered evidence of massive galaxies slamming into each other, identified vast clusters of stars, helped discover new exoplanets and mapped millions of galaxies and blazing galactic monsters called quasars.

A study last year using Gaia data identified two streams of ancient stars at the Milky Way's heart thought to have formed around the galaxy's birth more than 12 billion years ago.

According to astronomers using Gaia, the Milky Way then swallowed other dwarf galaxies as it grew -- notably one called Gaia-Enceladus around 10 billion years ago.

source: AFP