On Tuesday, after an embargo break on a Croatian website, Nature released news of the discovery of an Earth-sized planet right next door–a mere 25 trillion miles away, according to Seth Borenstein of The AP. That's farther than Croatia, but if you're an astronomer, it's right in your face.
The planet, which circles Alpha Centauri, is far too hot to support life, Borenstein reports, but it's likely that other planets circle the same star, and one of them could be in what's called the Goldilocks zone–not too hot, not too cold, but just right.
Dennis Overbye at The New York Times said the discovery was "bringing the search for another Earth about as close as it will ever get." He also worked into his lede that Alpha Centauri is a triple star system and is only 4.4 light-years away, which sounds a lot closer than 25 trillion miles–but isn't. As Eric Hand at Nature put it, the planet is "so close that E.T. could phone home in just four years."
The planet is a rocky ball, Overbye reports, circling Alpha Centauri B at a distance of only about four million miles. He quotes Debra Fischer of Yale, who says, "The discovery that our nearest neighbor has rocky planets is the story of the decade."
Adam Mann at Wired gives us the essential science-fiction references, noting that the Alpha Centauri system was the setting for the home world of the Transformers (Cybertron) and for the home world of Na'vi in Avatar (Pandora). I did not know that.
A couple of people called my attention to a piece by Lee Billings at centauri-dreams.org in which he provides thoughtful perspective on the search for planets outside the solar system and where that research might be headed. If you're not excited yet, read Phil Plait at Bad Astronomy. His excitement ("Huge news!") is irresistible.
By today, however, the discovery was old news as attention turned toward interstellar travel, and whether humans–or a probe–might be sent to this planet-next-door. Fischer, who was evidently so excited she could barely contain herself, told Nadia Drake of Science News for her Tuesday story that "if you were going to send a spacecraft anywhere, or a probe anywhere, that's where you'd go first."
Ross Andersen at The Atlantic wonders, in his headline, whether we could send humans to the newly discovered planet. He asks MIT planetary scientist Sara Seager, who says that the Voyager spacecraft, now at the edge of the solar system, is traveling at 20 kilometers per second, which would get it to Alpha Centauri in 70,000 years. That's a long time to wait to publish a paper. But "there are a lot of people who think we have the capabilities to get to a tenth of the speed of light" for interstellar travel, which would get a probe or a human being there in 40 years, she said.
Ian O'Neill at Discovery News interviews Richard Obousy, co-founder and president of Icarus Interstellar Inc., which wants to send an unmanned probe to another star system within the next century. He calls Alpha Centauri "a comparatively easy destination."
If he's comparing it to trying to get crosstown in Manhattan, he's probably right.