July 17, 2013
For all the new, exotic things astronomers discover in the universe, it’s almost more exciting to find out there was something hanging out in our own neighborhood that we never knew was there. This week, the SETI Institute announced that one of its astronomers, Mark Showalter, found a never-before-seen moon around Neptune, its 14th (circled above), noting that it was even missed by Voyager 2 when it flew by and surveyed the planet’s rings and moons in 1989. He used the Hubble Space Telescope to study the planet, then re-processed and combined 150 images in sets of eight to 10.
The news sounded a bit familiar. Air & Space interviewed Showalter earlier this summer about studying the solar system, and he told us a similar story. You can read the interview in full in our feature on the Hubble Space Telescope, part of our upcoming 2013 special collector’s edition on aerospace inventions, The Genius Factor, which arrives on newsstands this August. Here’s a snippet, in which we asked him about imaging the rings of Uranus:
“Hubble remains far and away the most powerful instrument we have for studying the families of small moons orbiting the outer planets,” Showalter says. “I find it remarkable that Mab and Cupid were too small to be noticed by the Voyager spacecraft during its 1986 flyby of Uranus, but we could see them using Hubble years later.” Showalter used the same “observing trick” on Pluto and discovered two tiny moons in 2011 and 2012.
April 19, 2013
The Kepler team’s announcement of the smallest, most Earthlike planets yet discovered in a star’s habitable zone naturally got SETI-ologists wondering whether alien civilizations might be broadcasting from Kepler-62e or -62f.
It turns out that one SETI group has already listened for signals.
Two years ago, a team led by Andrew Siemion of the University of California at Berkeley trained the giant Robert C. Byrd Green Bank Telescope in West Virginia on 86 selected “Kepler objects of interest” — confirmed or suspected planets found by NASA’s orbiting telescope since its launch in 2009. The targets were chosen based on several criteria: if the planets were within a specific mild temperature range, or if they were just a little bigger than Earth and relatively far from their host star, or if the star had five or more candidate planets. One of the 86 stars on the list was an orange dwarf designated KOI 701, now better known as Kepler-62, home to the planetary system announced yesterday.
For each of the stars, the Green Bank telescope searched the entire frequency range between 1.1 and 1.9 gigahertz, listening for “narrow-band” signals no more than a few hertz wide, which, according to a paper by Siemion and his colleagues in The Astrophysical Journal, are, “as far as we know, an unmistakable indicator of engineering by an intelligent civilization.” Other SETI searches have targeted Kepler candidate planets, but the Green Bank search between February and April 2011 was the most sensitive yet.
Alas, “no signals of extraerrestrial origin were found” for KOI 701 or any of the other 85 targets, report the scientists. That’s not a surprising result in SETI, where absence of evidence is not evidence of absence.
So the search will continue. Having looked for narrow-band signals, the next step, says Siemion, is to hunt for other patterns in the data that would be harder to detect. Within the next couple of months, he and his colleagues plan to add their Kepler data to the SETI@Home archive, so that volunteers around the world can use their own computers to help crunch the numbers and look for signals.
Down the line, he sees other opportunities to tune in to the Kepler-62 planets. One scenario for possible alien transmissions is that extraterrestrial civilizations would use radio to communicate from one planet to another — if, like us, they’ve begun exploring their own solar system. Because we see the Kepler-62 system more or less edge-on, the planets will regularly line up with each other from our point of view, so that we can search at radio or even optical wavelengths for a beam directed from one planet to another. The next such conjunction of Kepler 62e and 62f happens on July 30.
“The Kepler planets are so exciting,” says Siemion, not just in themselves (although at 1,200 light years away, they’re too distant to explore in detail), but because they herald a new era of studying planets we know to be Earthlike in size and composition. He’s looking forward to the launch of TESS (the Transiting Exoplanet Survey Satellite) in 2017. While Kepler’s job is to collect statistics about how common planets are around distant stars, TESS will hunt for Earthlike worlds in our own celestial neighborhood — 10 or 15 light years away. That’s close enough, says Siemion, where SETI searches could pick up FM radio and television transmissions of the kind now leaking out from Earth every day.
December 8, 2011
If any of you aliens out there rang our Earth line this summer, would you kindly try dialing in again? After an eight-month down time, SETI — the Search for Extraterrestrial Intelligence — is back up and running this week thanks to an influx of funds. The Allen Telescope Array (ATA) in Northern California, SETI’s primary search facility, was forced into hibernation on April 25 by severe budget cuts. “Hibernation” meant it would be staffed by a skeleton crew to keep the facility safely maintained, but all observations would cease.
ATA started operations in 2007 as the first radio observatory built specifically to scan for intelligent life elsewhere. It was funded primarily through the National Science Foundation and the State of California, through UC Berkeley, which co-operates the Hat Creek Radio Observatory, where ATA is located, with SETI, but both sources slashed their contributions earlier this year. In an April letter to supporters, SETI Institute CEO Tom Pierson said that NSF funding “has been reduced to approximately one-tenth of its former level … compounded by growing State of California budget shortfalls.”
The nonprofit organization spent a summer passing the hat, launching SETI Stars to raise over $200,000 through online donations, including one from Contact star Jodie Foster, and teaming up with the U.S. Air Force, which hopes to use the facility for tracking objects in orbit. Scientists fired up the ATA on Monday, starting with some of the most recent discoveries by NASA’s Kepler space telescope. Jill Tarter, Director of the Center for SETI Research, said in a press release, “For the first time, we can point our telescopes at stars, and know that those stars actually host planetary systems – including at least one that begins to approximate an Earth analog in the habitable zone around its host star.”
The SETI Institute will continue to raise funds to keep the ATA running, and plans to spend the next two years studying the Kepler catalog. On the same day ATA went back online, the Kepler team confirmed they’d found their first planet, Kepler 22-b, orbiting in the habitable zone of a star similar to our sun.
December 2, 2010
Score another one for the extremophiles.
Biologists had already discovered organisms that can survive everything from high levels of radiation to vacuum to total darkness. Now they’ve found one that uses arsenic as a substitute for phosphorus, one of the six elements (carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus) we thought until now was necessary for life. Astrobiologists are excited, because it’s one more way extraterrestrial life could evolve.
Like that search wasn’t complicated enough already.
December 8 update: Not everyone’s buying it.
September 13, 2010
Most people date the modern Search for Extraterrestrial Intelligence (SETI) to Frank Drake’s Project Ozma, conducted in 1960 using the giant dish at the National Radio Astronomy Observatory in Green Bank, West Virginia.
Today through Wednesday, at an NRAO workshop, SETI-ologists will review where their field stands on its 50th anniversary. Tune in to the webcast here.
Then read Paul Davies’ provocative new book, The Eerie Silence, and talk to the author in our online chat on September 20.
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