Kepler is the world’s first mission with the ability to find true Earth analogs — planets that orbit stars like our sun in the “habitable zone”. The habitable zone is the region around a star where the temperature is just right for water. The Kepler Space Telescope was launched on March 7, 2009 and its main purpose was to observe and study regions of the Milky Way Galaxy closer to the Earth. To put things in perspective, it is so powerful that from space, it could detect a person in a small town turning off a porch light at night. Initially, KST was launched for the three and a half year long mission and cost $550 million, but the mission lasted for nine years in deep space. During this time period, KST collected data that indicated that our sky is filled with billions of hidden planets.
Although NASA’s Kepler Space Telescope had run out of fuel needed for further science operations, it has transmitted promising data back to Earth.
According to NASA, a team of transatlantic scientists were looking through old observations from the now-retired Kepler space telescope when they discovered the planet, Kepler-1649c, orbiting in its star’s habitable zone. Kepler ran out of fuel and went to sleep in 2018, but scientists are still studying the data it collected during its epic hunt for planets beyond our own solar system. Of all the exoplanets found by the Kepler telescope, NASA says that this distant world – which is located 300 light-years from us – is most similar to Earth in size and estimated temperature. The planet is located in its star’s habitable zone, a region where it’s possible for liquid water to exist.
Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington, said: “This intriguing, distant world gives us even greater hope that a second Earth lies among the stars, waiting to be found. “The data gathered by missions like Kepler and our Transiting Exoplanet Survey Satellite (TESS) will continue to yield amazing discoveries as the science community refines its abilities to look for promising planets year after year.”
However, it might be a bit early for us to start packing as there are still many things yet to be known about the planet.
The exoplanet is approximately 1.06 times larger than Earth and the exoplanet’s temperature may be similar to our planet’s, because it receives 75% of the amount of light we get from our own sun. The team of scientists behind the Kepler mission designed an algorithm, called Robovetter, to look through the data, and determine which of the brightness dips were likely exoplanets and which were false positives. Initially, the planet was misidentified by the algorithm, but the team of scientists unearthed it six years later while manually reviewing Kepler data.
“If we hadn’t looked over the algorithm’s work by hand, we would have missed it,” Andrew Vanderburg, a researcher at the University of Texas at Austin and first author on the paper, said in a statement.
While it might look promising, scientists say that the Kepler-1649c is in orbit around a type of star that “is known for stellar flare-ups that may make a planet’s environment challenging for any potential life”. Apart from that, very little is also known about what the planet’s atmosphere consists of, with further tests needed to determine whether it is even capable of supporting life. However, we do know that it is in the Goldilocks Zone – a region around a star where it is neither too hot, nor too cold for life to exist.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal”.
NASA also explained that since Kepler-1649c has an extremely close orbit with the star known for stellar flare-ups, a year on Kepler-1649c is equivalent to only 19.5 Earth days. There are other exoplanets estimated to be closer to Earth in size and in temperature, but NASA says there is no other exoplanet that is considered to be closer to Earth in both of these values that also lies in the Goldilocks Zone.