Imagine a Family Tree of 1 Billion Stars

Over 2,000 years ago, Greek astronomer and mathematician Hipparcus of Nicea catalogued the position of about 1,000 stars in our galaxy. This would remain a significant achievement for hundreds of years.

The Gaia Telescope, which launched into space on December 19, will mark a similar accomplishment but on an exponentially more massive scale. Over the next 5 years, the telescope will observe 1 billion stars in the Milky Way galaxy.

Developed by the European Space Agency (ESA) and aerospace company Astrium, the Gaia Telescope will provide the most accurate map of the Milky Way to date.

Over the next 5 years, the Gaia Telescope will continuously rotate and scan the sky for stars. Each of the billion stars will be observed an average of 70 times, allowing the telescope to collect enough data to accurately measure each star’s position, brightness, temperature, chemical composition and other properties.

So what is it scientists hope to find?

First, by measuring the position, motion, and properties of each star, scientists will be able to assemble a family tree of the Milky Way galaxy. Scientists plan on putting the motion of the stars in “rewind” and “fast forward” to learn more about where stars came from, how the Milky Way was born and also project how our galaxy will die.

Scientists also hope to uncover thousands of supernovae (dying stars which will eventually explode), new asteroids and also accurately test Einstein’s theory of General Relativity.

It will be a few months until the telescope is ready to observe stars however; it is currently traveling to its home orbit called L2. L2 is a virtual point in space that is gravitationally stable and is 1.5 million kilometers beyond Earth as seen from the Sun.

At the end of the 5 years, the project will have accumulated over 1 petabyte of data – the equivalent of 200,000 DVDs. 400 individuals across Europe will be heavily tasked with analyzing the data and drawing informed conclusions from it about our home galaxy.


Sam Sunmonu

Sam is a technology entrepreneur and enthusiast. Sam studied History while at Duke University and currently works for a NYC startup.