The planet, being called Kepler-1649c, was discovered by the team when they were looking through the data of previous observations from the Kepler telescope, which had been retired by NASA in 2018.
Planetary discoveries: A second Earth may have been found! Reanalyzed data from NASA’s Kepler Space Telescope, being used by a team of scientists, has led to the discovery of an Earth-size exoplanet. What’s more is that the exoplanet has been found orbiting in the habitable zone of its star, the space agency said in a press release. Habitable zone is that area around a star where a rocky planet can support liquid water, the agency further explained. The exoplanet is about 300 light years away from the Earth and is the most similar to our planet in size and temperature out of all the planets identified using Kepler, NASA said.
The planet, being called Kepler-1649c, was discovered by the team when they were looking through the data of previous observations from the Kepler telescope, which had been retired by NASA in 2018, the US space agency’s statement said. Kepler-1649c is only 1.06 times the size of Earth. Moreover, the amount of light the exoplanet receives from its star is about 75% of the amount of light Earth receives from the Sun, indicating a temperature similar to that of ours.
NASA is also looking at the discovery with excitement due to the fact that while Kepler-1649c in itself is similar to Earth in size and temperature, it also provides its system a whole new view. In their system, for every nine times that the outer planet orbits the host star, the inner planet revolves around the star almost exactly four times, which means that their system is extremely stable and is likely to last for long.
Why did Kepler-1649c come to light now?
The Kepler telescope had been retired in 2018, and had actually stopped collecting data from space in 2013. Therefore, we are left wondering how the exoplanet’s existence came to the fore now.
The agency explained in the statement that the planetary body had previously been misidentified while being searched by a computer algorithm, this team of researchers took a second look and identified it as a planet.
A computer algorithm, named Robovetter, was used by the space agency to sort through the huge data collected by the Kepler telescope, which looked at stars and searched for planets by observing the dips in their brightness as planets passed in front of them. However, most often, the dips in brightness were caused by bodies other than planets, like a change in the brightness of the star or maybe comets passing. The scientists created Robovetter to identify the 12% of the dips that were actually caused by planets and not other bodies. The algorithm labelled what it assessed as non-planetary dips in the brightness with the signature “false positive”.
Since the scientists were aware of the chances that the algorithm would likely give out errors at some point, a dedicated team known as Kepler False Positive Working Group was tasked with rechecking the false positive signatures to ensure that they weren’t missing out on any exoplanet and a subsequent discovery.
It was when this group was rechecking the algorithm’s false positives that it found that Kepler-1649c was in fact one of the errors made by Robovetter.
Kepler-1649c: What next?
The agency said that while the discovery is exciting, the exoplanet orbits a red dwarf, unlike the Earth. This type of star has never been observed in our system, but the red dwarf star has stellar flare ups which can pose a challenge for any potential life on a planet.
However, NASA is not letting this dampen its excitement. Talking about the discovery, NASA’s Science Mission Directorate associate Administrator Thomas Zurbuchen was quoted in the statement as saying that the discovery has given them hope of a second Earth lying among the stars, “waiting to be found”.
The statement further said that there is still a lot about the planet which remains to be known, including its atmosphere, which could impact the temperature prevalent on it. Moreover, the calculations about the exoplanet’s size also have a significant margin of errors, much like the calculations regarding all astronomical objects so far away, NASA said.
However, the discovery of Kepler-1649c is still exciting for the researchers, especially those who have been trying to establish the presence of life on other planets or discover other habitable planets.