NASA has launched a new space telescope to hunt for exoplanets

Update 18 April 2018: After a two-day delay, NASA’s Transiting Exoplanet Survey Satellite (TESS) launched aboard a Falcon 9 rocket from Cape Canaveral, Florida. Now, operators will use the satellite’s onboard boosters to push it into its final orbit before beginning its observations of distant worlds. NASA plans to operate TESS until at least 2020.

Update 16 April 2018: The scheduled 16 April launch of the TESS satellite has been delayed. A tweet from SpaceX, which operates the Falcon 9 rocket set to take the satellite to space, indicated that delays were required to conduct analysis of the rocket’s guidance, navigation and control system. The new targeted launch date is 18 April.

Standing down today to conduct additional GNC analysis, and teams are now working towards a targeted launch of @NASA_TESS on Wednesday, April 18.

— SpaceX (@SpaceX) April 16, 2018

Original article, published 13 April 2018
NASA’s next exoplanet-hunting telescope is preparing for launch. The Transiting Exoplanet Survey Satellite (TESS), is scheduled to blast off aboard a Falcon 9 rocket on 16 April.

TESS is taking up the mantle of the Kepler Space Telescope, which is expected to run out of fuel by the end of this year. Kepler has found more than 5000 exoplanet candidates so far, and confirmed about half of them. TESS will be able to search 350 times more area of the sky than Kepler can, and is expected to find about 20,000 exoplanets in its first two years alone.

It will take about two months after launch to manouevre the satellite into its orbit – about half as far from Earth as the moon – and test its cameras. “After that, there’ll just be a flood of information,” says the mission’s principal investigator, George Ricker at the Massachusetts Institute of Technology.

Eyes on the sky

TESS will use the same transit method Kepler used to find planets. This involves watching a star for dips in its light as a planet passes between the star and the telescope. How often the dips repeat indicates how fast the planet circles its host star, and the amount of light that’s blocked tells us the size of the distant world.

Rather than looking at distant stars in a small area of sky, like Kepler did, TESS will look at closer stars over 85 per cent of the sky. It is optimised to observe smaller, cooler stars that emit mostly red light.

“90 per cent of the stars in the Milky Way emit in those red wavelengths, and they seem to have more planets than stars like the sun, especially smaller Earth-sized planets,” says Ricker. “Nature’s really saying, ‘look here, look here’ and that’s exactly what we’re going to do.”

Because those stars are so nearby and rich with planets, they will be ideal targets for the James Webb Space Telescope (JWST), due to launch in 2020. JWST will examine exoplanet atmospheres for signatures of life, which is only possible when their stars are relatively close.

Read more: How to sniff aliens’ gas in exoplanet atmospheres