Alien Planets: European Spacecraft Could Find 70,000 New Alien Worlds, But Could Any Support Life?

How many alien planets really exist in the Milky Way galaxy? Astronomers found their first one back in 1995, and since then have added about 2,000 more to the list of known alien worlds, or “exoplanets,” and scientists believe they have barely scratched the surface.

But they are about to scratch a little deeper. The European Space Agency launched its Gaia spacecraft in December of last year, and the interstellar observatory, which cost about $1 billion to create, launch, and guide is now settled into its new home in space — almost a million miles from Earth.

That’s a long way out there — but still far closer to Earth than our nearest neighbor in the solar system, Mars. The Red Planet is about 34 million miles from Earth. And that’s when the two planets reach their closest point as they each orbit the sun.

From its vantage point, which is 930,000 miles away from Earth to be more precise, Gaia will proceed to discover what scientists expect to be as many as 70,000 new alien planets orbiting stars throughout the Milky Way galaxy. That total could be reached if Gaia is able to continue functioning for 10 years.

But the scientists in charge of the space observatory say that they’re just trying to get Gaia to get through a five-year stint in outer space. During that initial period, Gaia is expected to turn up about 20,000 alien planets.

Will Gaia be able to tell if any of these planets are capable of supporting life? That will depend on the planet. Many of the 2,000 or so planets so far discovered, scientists believe, are similar enough to Earth that they could support life. Gaia will look for alien worlds with Earth-like characteristics, but that’s not the sole focus of its mission. Michael Perryman, the Gaia project supervisor explains the mission in detail.

Each of these planets will be conveying some very specific details, and many will be highly interesting in their own way. If you look at the planets that have been discovered until now, they occupy very specific regions of discovery space. Gaia will not only discover a whole list of planets, but in an area that has not been thoroughly explored so far.”

Gaia’s primary mission is to help astronomers create an accurate 3-D map of the Milky Way by remotely exploring about a billion stars, but because scientists generally believe that the Milky Way averages at least one planet for every star, Gaia is likely to come across alien planets by the thousands.

[Image: Artist’s Rendering via WikiMedia Commons]