After traveling 94 million miles into deep space, the journey of NASA’s Kepler space telescope was finally completed in October of 2018. Operational since 2009, the telescope was able to detect a total of 2,681 exoplanets before running out of fuel. The archival data retrieved by Kepler will have immense value as it is continued to be analyzed by astronomers. Notably, this data has led to an astonishing discovery just this week.
Astronomers have identified an exoplanet 300 light-years away that has various promising Earth-like qualities. The planet is named Kepler-1649c. As we learned in class, both size and distance from a star impacts the habitability of any planet. Earth is the correct size and distance from the Sun to support liquid water and life. Kepler-1649c is only 1.06 times the size of Earth and receives 75% of the light compared to what Earth gets from the Sun. It orbits a red dwarf star which is much smaller and cooler than our star and therefore, must orbit much closer than we do to the Sun. A complete orbit of Kepler-1649c only takes about 19.5 Earth days.
There are still many things we do not know about this potentially habitable Earth-like planet. Due to barriers inherent to exoplanet detection methods, we do not know the composition of the atmosphere. This could impact the assumed temperature of the planet’s surface and reduce its ability to sustain life.
Further, the information gathered by the Kepler telescope is not absolute. Kepler-1649c was initially written off as a false positive by a computer program. It is only now that scientists have recombed through some of the data to discover this planet. Additionally, scientists suspect that there is another candidate planet in the same solar system. By analyzing orbital resonances, it is theorized that there might be a slightly closer planet that is also in the habitable zone of the star.
To conclude, missions like Kepler and TESS (Transiting Exoplanet Survey Satellite) provide vital data that can be analyzed to discover promising planets even after they have stopped transmitting. Thomas Zurbuchen, associate administrator at NASA’s Science Mission Directorate says that Kepler-1649c “gives us even greater hope that a second Earth lies among the stars, waiting to be found.”