Unless the planets are very young and very large, no instruments are currently capable of directly imaging these planets. While some planets have been found by direct imaging (that is, appearing in a photo along with its star) it’s not possible of yet with Proxima, a 5 billion year old planet.
A star might have all of its planets aligned at a 90-degree angle from us, with the planets orbiting in such a way that they never pass in front of their star for our telescopes to see. In order to witness a transit, the orbital plane of the planets must be at or near our line of vision, but not all solar systems have the same orientation. Kepler found thousands of planets by staring at 145,000 stars in a minute region of the sky at the tail end of Cygnus, waiting for the 1 percent chance a planet would directly pass in front of a star and cause a dip in its light, in a method known as transiting.īut the problem with the Proxima Centauri planet is that it doesn’t transit - at least not from our vantage point. So how was there a planet hiding around the closest star to us, just waiting to be discovered? The simple answer: Finding a planet is really hard. At a diameter of 124,274 miles (200,000km), it’s only 1.43 times the diameter of Jupiter. Its distance of 4,349,598 miles (7 million kilometers) from its star may seem tiny, at just one-fifth the distance between Mercury and the Sun, but Proxima Centauri is the runt of the litter in the Alpha Centauri system. Then there was the Kepler telescope, which found thousands of planets, including some in the habitable zone, and some within a few dozen light-years of us.Īnd now there’s a planet of 1.3 Earth masses right next door, zipping around its star in 11.2 days. “Twenty years ago, we were finding the first exoplanets and it was totally exciting,” he says. “I think it actually marks a transition,” Jeffrey Coughlin, a SETI Institute scientist not involved in the study who assembles the Kepler catalog, says. That means that there is no solar system that will be closer to Earth in our lifetimes.Īnd so far, the exoplanet, named Proxima Centauri b, is shaping up to be quite Earth-like, roughly the mass of our planet and in just the right place where, if it has an atmosphere, liquid water could exist on the surface. What’s more, that star is Proxima Centauri, only 4.24 light-years away. Headlines tout each discovery as “the most Earth-like planet yet.” Many of those planets are far away.īut a new discovery published August 24 in Nature hits closer to home, with an Earth-mass planet in the habitable zone of its star. The hunt for exoplanets has, in some ways, been about the hunt for an Earth-like planet – something warm where water could exist.
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