NASA hosted a live audio conference today to reveal what could be the most exciting development of the decade in space news: the Kepler Space Telescope has discovered the most Earth-like planet known to date. Although there hasn’t been a report of little green men, Kepler-452b is being described as “the most Earth-like planet outside of Earth”—a rocky, similarly-sized planet where liquid water can exist, orbiting another star in the same way our earth orbits the sun.
Kepler-452b is not the first planet of its kind that NASA has discovered. The first such exoplanet was located in 1995 and followed by literally thousands of others in the intervening years. However, this new discovery is the most Earth-like of all the contenders, although it is slightly larger and warmer than our planet. What makes 452b such an important discovery, according to Jeff Coughlin, Kepler research scientist at SETI Institute, is not only the characteristics of the planet itself but of the sun it orbits, which is much more like our sun than the stars that previous candidates were related to.
John Grunsfield, associate administrator of NASA’s Science Mission Directorate, was the lucky bearer of the incredible news. After a dramatic introduction and various musings about the origins of all life, Grunsfield broke the news by saying that a planet has been identified as “a pretty good close cousin” to our Earth. His announcement was followed by technical details from Jon Jenkins, Kepler data analysis lead at NASA’s Ames Research Center. Jenkins summarized the previous discoveries, outlining that while many “Earth-like” planets had been identified, they all fell short in some way or another. Kepler-452b is closer in size, closer in terrain, closer in temperature, although it has approximately twice as much gravity as we experience on Earth.
So, 452b is an Earth-like planet, but can it support life? Nobody knows, but much like a scientific Magic 8-ball, “outlook is good.” Jenkins said it’s too soon to say definitively whether the surface is rocky, like our planet, and the temperatures of its neighboring stars seems to suggest that it might be the kind of place where water can exist in its liquid form, which is an amazingly telling sign when it comes to a planet’s potential for being “home.”
Kepler is a spacecraft launched in 2009 that looks a bit like a giant floating vacuum cleaner. Its express purpose is the search for Earth-like planets in other solar systems. A new volume of planetary discoveries will be issued next year, so stay tuned to find out whether Kepler scientists are able to identify any other Earth-like planets who beat out Kepler-452b on the planetary family tree.
Images via NASA