Launching today: NASA's new satellite seeking "alien" Earths

Today, SpaceX expects to launch a Falcon 9 rocket to deliver NASA's Transiting Exoplanet Survey Satellite (TESS) into orbit. Scientists expect TESS to find thousands of exoplanets by detecting when they pass in front of their host stars, briefly blocking the light of those suns.

“A few months after TESS launches, we will be able to point out the first ones of these familiar stars, which host planets that could be like ours,” says Cornell University astronomer Lisa Kaltenegger, director of the Carl Sagan Institute.

From Nadia Drake's excellent FAQ on TESS in National Geographic:

The search for life beyond Earth is necessarily constrained by what we know. Life as we don’t know it could be anywhere, and it doesn’t care that we haven’t deigned to imagine it yet. To help focus the hunt, astronomers are starting by looking for something familiar. And we know that at least once, life evolved on a warm, rocky planet orbiting a relatively stable star.

That being said, many of the stars TESS will scrutinize will be smaller and dimmer than our own: the cool, reddish M dwarfs that are the most common types of stars in the Milky Way. Planets orbiting these stars at a distance that’s neither too hot nor too cold for liquid water to exist are going to be snuggled in quite close—orbiting near enough to their stars for scientists to find them on months-long time scales.

In addition, the worlds TESS expects to find will be better situated for observations that could reveal whether alien metabolisms are churning away on their surfaces, beneath their seas, or in their clouds.

The launch is scheduled for 6:32pm EDT. Watch live on NASA TV along with other events throughout the day.