"When you're now approaching the question of are we along in the universe you've suddenly got a whole treasure chest of planets that could be in the position to support life". "Oxygen is our best biosignature gas on Earth", Seager said, so we're looking for what we know. "One of the big surprises from Kepler was to find this whole population of planets with sizes between that of Neptune and Earth - and there aren't any in our solar system, zero - and they're everywhere out there", said Latham, who's worked on the Kepler project for almost 20 years.
Yet planets can, from our viewpoint, appear to travel or "transit" across the face of their star as they orbit, blocking a small fraction of the star's light.
NASA predicted that the TESS will be covering about 200,000 exoplanets which are present outside of our solar system which includes more than 50 Earth-size planets and about 500 planets which care less than twice the size of the Earth.
But Kepler covered only a small patch of sky containing few stars bright enough for us to study their planets.
"With the two-minute pictures, you can get a movie-like image of what the starlight is doing as the planet is crossing in front of its host star", Guerrero said. The most successful has been the UK-led Wide Angle Search for Planets (WASP) project, of which I am a member.
It'll take TESS about two years to survey around 85 percent of the sky, looking out at a field that includes more than 20 million stars, according to MIT.
But ground-based transit surveys have one big limitation: they look through Earth's atmosphere and that severely limits the data quality. TESS will survey the local neighborhood for planets like Earth.
TESS will be able to see planets that are very far away and put out very little light.
Artist's illustration of TESS in space. The first year of observations will map the 13 sectors encompassing the southern sky, and the second year will map the 13 sectors of the northern sky.
"TESS is kind of like a scout", TESS scientist Natalia Guerrero said in a statement.
"There are so many things that TESS may find that are related to exoplanets and phenomenon we know already", he said. But planets orbiting dimmer, cooler red dwarf stars might be at the right temperature for life even if they are so close.
The US space agency is to find out with a series of experiments if making space babies is possible, which would be of crucial importance when the time to colonize planets comes. The targets TESS finds are going to be fantastic subjects for research for decades to come.
This exploration is a step towards finding rocky planets in the habitable zone of stars like our sun. As said, it will be launched in orbit from Cape Canaveral, Florida, on April 16th, and will continue the job done by the Kepler Space Telescope, which was the NASA's primary exoplanets observer but which will soon run low on fuel. A handful of Kepler exoplanets might be like our own Earth.