NASA and SpaceX are targeting the launch of NASA’s Transiting Exoplanet Survey Satellite, or TESS, on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station for no earlier than 6:51 p.m. EDT.
Frequent updates from the countdown will begin here at 6:30 p.m. You can also watch at http://www.nasa.gov/live.
TESS is the next step in the search for planets outside of our solar system. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey the nearest and brightest stars for two years to search for transiting exoplanets.
Like the successful Kepler mission before it, TESS will watch for signs of planets passing in front of the stars they orbit.
When a planet crosses in front of its star, that’s called a transit – and it results in a short-lived flicker in the starlight seen by an observer.
TESS will find the most promising exoplanets orbiting our nearest and brightest stars, giving future researchers a rich set of new targets for more comprehensive follow-up studies.
The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat.
TESS stars will be 30-100 times brighter than those surveyed by the Kepler satellite; thus, TESS planets should be far easier to characterize with follow-up observations. These follow-up observations will provide refined measurements of the planet masses, sizes, densities, and atmospheric properties.
TESS will monitor the brightnesses of more than 500,000 stars during a two-year mission, searching for temporary drops in brightness caused by planetary transits. Transits occur when a planet’s orbit carries it directly in front of its parent star as viewed from Earth. TESS is expected to catalog more than 3000 transiting exoplanet candidates, including a sample of ~500 Earth-sized and ‘Super Earth’ planets, with radii less than twice that of the Earth. TESS will detect small rock and-ice planets orbiting a diverse range of stellar types and covering a wide span of orbital periods, including rocky worlds in the habitable zones of their host stars.
• Cover 400X larger sky area than Kepler
• Span stellar spectral types of F5 to M5
TESS could find as many as 20,000 new exoplanets, most of which will be circling M-dwarf stars that are one quarter to one half the diameter of the sun and much dimmer and cooler. M-dwarfs, which comprise about 70 percent of stars in the Milky Way, are TESS’s primary targets.
TESS will tile the sky with 26 observation sectors:
• At least 27 days staring at each 24° x 96° sector
• Brightest 100,000 stars at 1-minute cadence
• Full frame images with 30-minute cadence
• Map Northern hemisphere in first year
• Map Southern hemisphere in second year
• Sectors overlap at ecliptic poles for sensitivity to smaller and longer period planets in JWST Continuous Viewing Zone (CVZ)
TESS will provide prime targets for further, more detailed characterization with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS’s legacy will be a catalog of the nearest and brightest stars hosting transiting exoplanets, which will comprise the most favorable targets for detailed investigations in the coming decades.
The Kepler project has provided ground-breaking new insights into the population of exoplanets in our galaxies; among the discoveries made using data from Kepler is the fact that the most common members of the exoplanet family are Earths and Super-Earths. However, the majority of exoplanets found by Kepler orbit faraway, faint stars. This, combined with the relatively small size of Earths and Super-Earths, means that there is currently a dearth of such planets that can be characterized with follow-up observations.