NASA’s planet-hunting Kepler space telescope — which has led to the discovery of over 2,300 planets so far — was roused from sleep mode and has restarted its scientific operations. The US space agency has been closely monitoring the probe since it is expected to run out of fuel soon. The spacecraft went into sleep mode after successfully downloading data from its 18th observation campaign. “After being roused from sleep mode the spacecraft’s configuration has been modified due to the unusual behavior exhibited by one of the thrusters,” NASA said in a statement.
The space telescope, originally launched in March 2009, has had a tumultuous year. The team placed Kepler into hibernation in July, as their new planet-hunter, the Transiting Exoplanet Survey Satellite (TESS), began testing for its own mission. The hibernation-like state was to ensure that the data from Kepler’s 18th mission, stored onboard the spacecraft, would be able to make its way back to Earth.
In total, the Kepler mission has confirmed the existence of 2,652 exoplanets and 30 of those exist within the Small Habitable Zone, the area of space surrounding a star where a planet could theoretically support a surface of the liquid water (and potentially extraterrestrial life).
Launched in 2009, the Kepler mission is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-sized and smaller planets in or near the habitable zone and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.
About TESS mission:
The Transiting Exoplanet Survey Satellite (TESS) is a NASA mission that will look for planets orbiting the brightest stars in Earth’s sky. It was led by the Massachusetts Institute of Technology with seed funding from Google.
The mission will monitor at least 200,000 stars for signs of exoplanets, ranging from Earth-sized rocky worlds to huge gas giant planets. TESS, however, will focus on stars that are 30 to 100 times brighter than those Kepler examined. This will help astronomers better understand the structure of solar systems outside of our Earth, and provide insights into how our own solar system formed.
TESS will occupy a never-before-used orbit high above Earth. The elliptical orbit, called P/2, is exactly half of the moon’s orbital period; this means that TESS will orbit Earth every 13.7 days. Its closest point to Earth (67,000 miles or 108,000 kilometers) is about triple the distance of geosynchronous orbit, where most communications satellites operate.
It will use transit method to detect exoplanets. It watches distant stars for small dips in brightness, which can indicate that planet has passed in front of them. Repeated dips will indicate the planet passing in front of its star. This data has to be validated by repeated observations and verified by scientists.