HUZZAH! SEVEN “NEARBY” “HABITABLE” PLANETS!
Not to denigrate the scientific achievement, which is noteworthy for its novelty and sophistication. Not to denigrate (much) the excitement on Twitter and other media, rounded up by Becky Ferreira at Motherboard.
But let’s bring a little reality to the boistrous celebration attending the revelation that astronomers have discovered at least 7 “Earthlike” planets orbiting the “nearby” star TRAPPIST-1.
Never heard of TRAPPIST-1? That’s because it’s a tiny dim star, one of zillions of red dwarfs, cool only in the sense that its temperature is low compared with many other stars. For example, our own Sun, which is 10 times the size of TRAPPIST-1.
TRAPPIST-1 is so undistinguished that it was named after the Earth-based telescope that discovered it, the TRAnsiting Planets and PlanetesImals Small Telescope in Chile. (The star’s formal name: 2MASS J23062928-0502285.)
But the planets themselves were discovered, huddling close to the star, by NASA’s Spitzer Space Telescope. So the news has been accompanied by a PR storm that is among NASA’s flashiest efforts, especially about hyping fantasies of alien life. See, for example, Eric Mack’s post at Cnet.
The Hubble is now screening four of the planets. We can expect to learn more about the magnificent seven from the James Webb space telescope, scheduled for launch next year. With the Webb, Philip Perry says at Big Think, “Astronomers will not only be able to detect large exoplanets, they’ll be able to prove whether or not a particular one has an atmosphere, by observing whether or not starlight filters through in a certain way.”
But let’s ratchet down the expectations to rational levels. The TRAPPIST-1 system is “nearby” only in the most relative sense: 39 light years. By contrast, our closest star, Proxima Centauri, is 4.2 light years away–and it also has an “Earthlike” planet, which I discussed here at On Science Blogs last year when it was discovered.
A video at LiveScience says it would take the Space Shuttle 1.5 million years to get to TRAPPIST-1. It’s only 75,000 years to Proxima Centauri. (Lots of TRAPPIST-1 videos and other graphics at nearly every post I mention here.)
The planets’ most Earthlike features are their size and probable rockiness. Three of them–TRAPPIST-1e, f, and g–could have liquid water. But all of them, says John Timmer at Ars Technica, are probably tidally locked.
Meaning that one side is always facing TRAPPIST-1 and so is in perpetual daylight. On the other side, which faces away from the star, it is always nighttime. Not terribly promising, at least for life-as-we-know-it.
Another downer: these planets are likely bathed in very high frequency ultraviolet radiation, which sterilizes anything in its path. Deborah Byrd discusses some possible counter-strategies at EarthSky. Life could be protected from radiation, as it is on Earth, if a planet had an ozone layer in its atmosphere. Or if life evolved underground or deep in an ocean. Or if it evolved protective strategies, as biofluorescent life forms do here on Earth.
Although Franck Marchis put a jubilant hed on his post at Cosmic Diary (“Wonderful Potentially Habitable Worlds Around TRAPPIST-1”), he veers toward truth-telling in the body of his post (“No, we have not yet discovered a cousin of Earth, much less seven of them. . . their location in the habitable zone of their star does not imply that they are habitable.” [Italics mine.])
Oh. Is this evidence of Trump effects on astronomy?
No. Apparently astronomers came up with this counter-intuitive definition of “habitable” on their own. “While we would certainly classify our own planet as habitable, the term could be applied to any of a wide range of lethal nightmare planets,” Katie Mack has observed at Cosmos.
And “they’re just three planets; as Sean Carroll wrote on his Facebook page, urging caution, “Evergreen caution: the observable universe could have 10^25 planets, and the chance that any one of them has life might be 10^-100.” (That’s 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001). Still, the possibility that we’ll find life out there, which fascinates people, especially evolutionary biologists, means that we’ll cling to the smallest probabilities,” Jerry Coyne observed at Why Evolution is True.
Also, Big Think’s Perry points out that TRAPPIST-1 burns so slowly that it’s likely to outlast the Sun by a trillion years. So when future Homo sap is forced to consider emigration from Earth, TRAPPIST-1 might be a new neighborhood to aim for.
And if not TRAPPIST-1, lots of other possibilities seem likely to emerge. Whatever we eventually learn about the TRAPPIST-1 planets, Paul Glaister says at Centauri Dreams, “we’re seeing such an abundance of possibilities here that similar, possibly life-bearing systems are doubtless commonplace. . . We’re swiftly moving to a place where the active search for biosignatures in distant atmospheres becomes a regular activity.”
SCIENTISTS MARCH EARLY IN BOSTON
You know those scientist marches scheduled for Earth Day April 22 and discussed here at On Science Blogs a couple weeks ago? Some scientists couldn’t wait . Hundreds of them marched last weekend, especially in Boston.
That march was timed to coincide with the annual meeting of the American Association for the Advancement of Science (AAAS), although the organization was not a sponsor, Karen Weintraub reported at SciAm. There were several sponsors, though: the Union of Concerned Scientists, Greenpeace USA, Mass Sierra Club and groups from area universities.
AAAS may not have been a sponsor of the March, but at STAT Kate Sheridan reports that inside the meeting, it was all Trump, all the time. Weintraub said AAAS has remained officially neutral, but at the meeting AAAS CEO Rush Holt pledged to help “make the march a success,” according to Sheridan.
Science historian Naomi Oreskes spoke at the meeting but also at the rally, where she said, “Our science has been politicized by people who are motivated to reject facts because those facts conflict with their worldview, their political beliefs, or their economic self-interest.”
As I noted in a previous post about scientific political activism, not everyone is a fan. At the AAAS meeting, Jim Gates, a physicist and former member of President Obama’s Council of Advisors on Science and Technology, said the Earth Day march seemed to him to lack an end goal, according to Hannah Devlin and Alan Yuhas at The Guardian. “As far as I can detect, there is no theory of action behind this,” he said.
HERE’S A THEORY OF ACTION: RUN FOR OFFICE
However, some 3000 scientists and STEM professionals seem to have developed just such a theory of action, according to Jason Koebler at Motherboard. That’s the number of people the group 314action says has so far expressed interest in the training session it is organizing about running for office. The training session for potential politicians was discussed here at On Science Blogs last month.
As a result of the intense enthusiasm, which 314action says has surprised it, plans have blossomed from a one-hour session to an all-day seminar. The seminar, for up to 200 potential political candidates, will feature training sessions run by politicians and organizers. It is scheduled for March 14 in Washington and will also be livestreamed. Sign up here for either the in-person seminar or the Webinar.