But there's a lot more than scientists can tell from a transit than just whether an exoplanet exists. TESS will do the same, searching for dimming brightness when a planet transits its host star.

The Falcon 9 payload fairing containing TESS.ДЄs previously mentioned, Kepler worked by examining and measuring the brightness of the stars it was focused on. During its two-year mission (which will probably be extended if the spacecraft works properly), TESS will study over 200,000 stars. After launch, the closest it will ever come to Earth is 67,000 miles, which will keep it outside the hazards of the Van Allen radiation belts. Unlike Kepler, TESS will actually be in an elongated orbit of the Earth, with an orbital period of 13.7 days. The brief launch window opens at 6:32 PM. That's where TESS comes in.ДЄ SpaceX Falcon 9 rocket will carry TESS into space, launching from Cape Canaveral Air Force Station's Launch Complex 40 in Florida. That's hard with Kepler's data because so many of its discoveries are far away - too far to really glean most details about these planets. Now, we want to know more about the distant worlds we do find. We don't need to know whether there are exoplanets out there anymore. TESS will operate differently than Kepler did. (And if the idea of a hard-working spacecraft slowly dying out in the cold vastness of space, struggling to reorient itself towards Earth one last time to send back word of its discoveries makes you weepy, know that you aren't the only one.) And none too soon: Kepler is low on fuel and will become just another piece of space junk soon.

Before Kepler, we didn't know much about these planets at all.Д«ut, armed with the knowledge that Kepler has given us, it's time for a new planet-hunting spacecraft that can apply what we've learned and expand it to new discoveries. Thanks to Kepler, we know that exoplanets are incredibly common in our galaxy - scientists have discovered that there are actually 1.6 planets for every star in the Milky Way. Scientists then analyzed the data that Kepler sent home and were able to confirm its exoplanet discoveries. By looking at a tiny part of a very big sky, Kepler was able to monitor when the brightness of these stars dimmed even the slightest bit, which signaled that something (like a planet) might be moving in front of it. As a result, it constantly monitored the brightness of around 150,000 main-sequence stars using an onboard photometer. Kepler's original mission, which was designed to last three and a half years, was to point itself at a single group of stars in the Cygnus-Lyra region. (It's also called the 'Goldilocks' zone, though presumably, there are no bears to be found on these distant worlds). Thirty of these are confirmed to be within the ' habitable zone' of their host star, which is close enough for liquid water to exist on the surface but not so close that the planet is scorched by the star's heat. It's called Kepler, and in the nine years it's been in space, this little satellite has found 2,342 confirmed exoplanets, with 2,245 more candidates that still need to be studied. We have a spacecraft that's currently in orbit of the Sun that has a similar job. Called TESS (the Transiting Exoplanet Survey Satellite), the spacecraft is designed to detect planets outside our solar system (called exoplanets) that are relatively close to our solar neighborhood. On Monday evening, NASA plans to launch a brand new satellite into orbit, courtesy of a SpaceX Falcon 9 rocket.

Spacex launches nasa planet-hunting s