World / Science & Health

Europe launches Gaia satellite to map Milky Way


The European Space Agency launched its star-surveying satellite Gaia into space on Thursday, hoping to produce the most accurate three-dimensional map of the Milky Way and to better understand the evolution of our galaxy.

Soon after the launch from French Guiana aboard a Russian-made Soyuz rocket, Gaia unfurled its 10-meter circular sun shield, which protects its sensitive instruments from the rays of the sun while simultaneously collecting solar energy.

Gaia is heading for a stable orbit at a point called Lagrange 2, 1.5 million km from Earth on the side away from the sun.

Timo Prusti, ESA’s project scientist, likened the mission’s goal to the switch from regular movies to 3-D. At the moment, he said scientists are working with a largely “flat” map of the galaxy.

Using its twin telescopes, Gaia will study the position, distance, movement, chemical composition and brightness of a billion stars in the galaxy — roughly 1 percent of the Milky Way’s stars.

The data will help scientists determine the Milky Way’s origin and evolution, according to Jos de Bruijne, deputy project scientist for the Gaia program.

Scientists have compared its positional accuracy to measuring the diameter of a human hair from 1,000 km away.

ESA has dubbed Gaia the “ultimate discovery machine” because its sophisticated instruments will allow scientists to look for small wobbles in stars’ movements that indicate the presence of nearby planets.

“Those are the stars that people are going to go out and look for planets around, and ultimately for signs of life,” said Fox.

Equipped with dozens of cameras capable of piecing together 1,000-megapixel images, scientists also expect to find hundreds of thousands of asteroids and comets inside our solar system.

Beyond that, scientists hope that Gaia can also be used to test a key part of Albert Einstein’s general theory of relativity that predicts “dips” and “warps” in space caused by the gravity of stars and planets.

Carmen Jordi, an astronomer at the University of Barcelona, said the satellite’s findings will become the main reference for scientists in the years to come, and “almost all the fields of astrophysics will be affected.”