On July 4, 2020, NASA’s Transiting Exoplanet Survey Satellite (TESS) completed its primary mission and is continuing its search for new extrasolar worlds.
An artist’s illustration of NASA’s Transiting Exoplanet Survey Satellite. Image credit: NASA’s Goddard Space Flight Center.
TESS was launched on April 18, 2018, with a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.
The planet-hunter monitors 24-by-96-degree strips of the sky called sectors for about a month using its four cameras and focuses on stars between 30 and 300 light-years away.
TESS looks for transits, the telltale dimming of a star caused when an orbiting planet passes in front of it from our point of view.
Among the mission’s recent planetary discoveries are its first Earth-size world, TOI-700d, which is located in the habitable zone of its star, and an infant planet around the young star AU Microscopii.
It also discovered TOI-1338b, a Neptune-sized alien world orbiting two stars, and LTT 1445Ab, a terrestrial planet orbiting a star in the triple-star system LTT 1445.
In addition to its planetary discoveries, TESS observed the outburst of Comet 46P/Wirtanen as well as numerous exploding stars.
The spacecraft discovered surprise eclipses in a well-known binary star system, solved a mystery about a class of pulsating stars, and explored a world experiencing star-modulated seasons.
Even more remarkable, TESS watched as a black hole in a distant galaxy shredded a Sun-like star.
“TESS is producing a torrent of high-quality observations providing valuable data across a wide range of science topics,” said TESS project scientist Dr. Patricia Boyd, a researcher at NASA’s Goddard Space Flight Center.
“As it enters its extended mission, TESS is already a roaring success.”
TESS spent its first year observing 13 sectors comprising the southern sky and then spent another year imaging the northern sky.
Now in its extended mission, TESS has turned around to resume surveying the south.
In addition, the TESS team has introduced improvements to the way the satellite collects and processes data.
Its cameras now capture a full image every 10 minutes, three times faster than during the primary mission.
A new fast mode allows the brightness of thousands of stars to be measured every 20 seconds, along with the previous method of collecting these observations from tens of thousands of stars every two minutes.
The faster measurements will allow TESS to better resolve brightness changes caused by stellar oscillations and to capture explosive flares from active stars in greater detail.
These changes will remain in place for the duration of the extended mission, which will be completed in September 2022.
After spending a year imaging the southern sky, TESS will take another 15 months to collect additional observations in the north and to survey areas along the ecliptic — the plane of Earth’s orbit around the Sun — that the satellite has not yet imaged.
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This article is based on text provided by the National Aeronautics and Space Administration.
