{"id":6360,"date":"2019-02-20T23:16:22","date_gmt":"2019-02-21T07:16:22","guid":{"rendered":"https:\/\/worldcampaign.net\/?p=6360"},"modified":"2019-02-21T05:21:16","modified_gmt":"2019-02-21T13:21:16","slug":"message-of-the-day-30","status":"publish","type":"post","link":"https:\/\/worldcampaign.net\/?p=6360","title":{"rendered":"Message of the Day: Environment, Personal Growth"},"content":{"rendered":"

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NASA\u2019s James Webb Space Telescope, National Geographic<\/em><\/span><\/p>\n

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We have reminded at times of the need to reflect on our place, as humans, and the place of planet earth and all life on it, in the larger universe. The new issue of the National Geographic Magazine takes us through a journey extroardinaire, by words, photos and graphics, to the next steps in the search for life beyond earth.<\/p>\n

We bow out and let the article do the talking:<\/p>\n

“Life probably exists beyond Earth. So how do we find it?”<\/a>,<\/p>\n

By Jamie Shreeve, Photographs by Spencer Lowell, Art by Dana Berry, National Geographic Magazine, March 2019 Issue<\/p>\n

With next-generation telescopes, tiny space probes, and more, scientists aim to search for life beyond our solar system\u2014and make contact.<\/em><\/p>\n

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In her office <\/b>on the 17th floor of MIT\u2019s Building 54, Sara Seager<\/a> is about as close to space as you can get in Cambridge, Massachusetts. From her window, she can see across the Charles River to downtown Boston in one direction and past Fenway Park in the other. Inside, her view extends to the Milky Way and beyond.<\/p>\n<\/div>\n

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Seager, 47, is an astrophysicist. Her specialty is exoplanets<\/a>, namely all the planets in the universe except the ones you already know about revolving around our sun. On a blackboard, she has sketched an equation she thought up to estimate the chances of detecting life on such a planet. Beneath another blackboard filled with more equations is a clutter of memorabilia, including a vial containing some glossy black shards.<\/p>\n

\u201cIt\u2019s a rock that we melted.\u201d<\/p>\n<\/div>\n

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Seager speaks in brisk, uninflected phrases, and she has penetrating hazel eyes that hold on to whomever she is talking to. She explains that there are planets known as hot super-Earths<\/a> whizzing about so close to their stars that a year lasts less than a day. \u201cThese planets are so hot, they probably have giant lava lakes,\u201d she says. Hence, the melted rock.<\/p>\n

\u201cWe wanted to test the brightness of lava.\u201d<\/p>\n<\/div>\n

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Laser beams streak from the European Southern Observatory\u2019s Very Large Telescope array in Chile\u2019s Atacama Desert. The lasers create artificial guide stars that help astronomers correct for distortions caused by atmospheric turbulence. The telescope is one of only a few able to directly capture images of giant exoplanets.PHOTOGRAPH BY GERHARD H\u00dcDEPOHL, ESO<\/p>\n<\/div>\n<\/figcaption><\/figure>\n

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When Seager entered graduate school in the mid-1990s, we didn\u2019t know about planets that circle their stars in hours or others that take almost a million years. We didn\u2019t know about planets that revolve around two stars, or rogue planets that don\u2019t orbit any star but just wander about in space. In fact, we didn\u2019t know for sure that any planets at all existed beyond our solar system<\/a>, and a lot of the assumptions we made about planet-ness have turned out to be wrong. The very first exoplanet found\u201451 Pegasi b, discovered in 1995\u2014was itself a surprise: A giant planet crammed up against its star, winging around it in just four days.<\/p>\n<\/div>\n

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\u201c51 Peg should have let everyone know it was going to be a crazy ride,\u201d Seager says. \u201cThat planet shouldn\u2019t be there.\u201d<\/p>\n<\/div>\n

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Today we have confirmed about 4,000 exoplanets. The majority were discovered by the Kepler space telescope<\/a>, launched in 2009. Kepler\u2019s mission was to see how many planets it could find orbiting some 150,000 stars in one tiny patch of sky\u2014about as much as you can cover with your hand with your arm outstretched. But its ultimate purpose was to resolve a much more freighted question: Are places where life might evolve common in the universe or vanishingly rare, leaving us effectively without hope of ever knowing whether another living world exists?<\/p>\n<\/div>\n

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Kepler\u2019s answer was unequivocal. There are more planets than there are stars, and at least a quarter are Earth-size planets in their star\u2019s so-called habitable zone, where conditions are neither too hot nor too cold for life. With a minimum of 100 billion stars in the Milky Way<\/a>, that means there are at least 25 billion places where life could conceivably take hold in our galaxy alone\u2014and our galaxy is one among trillions.<\/p>\n<\/div>\n

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Using a model, MIT astrophysicist Sara Seager demonstrates Starshade, under development at NASA\u2019s Jet Propulsion Lab in Pasadena, California. Deployed in space, the device, more than 100 feet in diameter, would block the light from a star. A space telescope would capture an image of a planet when it\u2019s between Starshade\u2019s petals, seeking evidence that life may exist on the planet.<\/div>\n<\/figcaption><\/figure>\n
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It\u2019s no wonder that Kepler, which ran out of fuel last October<\/a>, is regarded almost with reverence by astronomers. (\u201cKepler was the greatest step forward in the Copernican revolution since Copernicus,\u201d University of California, Berkeley astrophysicist Andrew Siemion told me.) It\u2019s changed the way we approach one of the great mysteries of existence. The question is no longer, is there life beyond Earth? It\u2019s a pretty sure bet there is. The question now is, how do we find it?<\/div>\n
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The revelation that the galaxy is teeming with planets has reenergized the search for life. A surge in private funding has created a much more nimble, risk-friendly research agenda. NASA too is intensifying its efforts in astrobiology. Most of the research is focused on finding signs of any sort of life on other worlds. But the prospect of new targets, new money, and ever increasing computational power has also galvanized the decades-long search for intelligent aliens.<\/p>\n<\/div>\n

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To Seager,<\/b> a MacArthur \u201cgenius award\u201d winner, participating on the Kepler team was one more step toward a lifelong goal: to find an Earth-like planet orbiting a sunlike star. Her current focus is the Transiting Exoplanet Survey Satellite<\/a> (TESS), an MIT-led NASA space telescope launched last year. Like Kepler, TESS looks for a slight dimming in the luminosity of a star when a planet passes\u2014transits\u2014in front of it. TESS is scanning nearly the whole sky, with the goal of identifying about 50 exoplanets with rocky surfaces like Earth\u2019s that could be investigated by more powerful telescopes coming on line, beginning with the James Webb Space Telescope, which NASA hopes to launch in 2021.<\/p>\n<\/div>\n

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On her \u201cvision table,\u201d which runs along one wall of her office, Seager has collected some objects that express \u201cwhere I am now and where I\u2019m going, so I can remind myself why I\u2019m working so hard.\u201d Among them are some polished stone orbs representing a red dwarf star and its covey of planets, and a model of ASTERIA, a low-cost planet-finding satellite she developed.<\/p>\n<\/div>\n

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NASA\u2019s James Webb Space Telescope is tested in a giant cryogenic chamber at Johnson Space Center in Houston, Texas, that simulates the frigid conditions of space. Far more powerful than the Hubble Space Telescope, it will probe the formation of stars, galaxies, and solar systems that could support life.PHOTOGRAPH BY CHRIS GUNN, NASA <\/small><\/div>\n<\/figcaption><\/figure>\n
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\u201cI haven\u2019t gotten around to putting this up,\u201d Seager says, unrolling a poster that\u2019s a fitting expression of where her career began. It\u2019s a chart showing the spectral signatures of the elements, like colored bar codes. Every chemical compound absorbs a unique set of wavelengths of light. (We see leaves as green, for instance, because chlorophyll is a light-hungry molecule that absorbs red and blue, so the only light reflected is green.) While still in her 20s, Seager came up with the idea that compounds in a transiting planet\u2019s upper atmosphere might leave their spectral fingerprints in starlight passing through. Theoretically, if there are gases in a planet\u2019s atmosphere from living creatures, we could see the evidence in the light that reaches us.<\/div>\n
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\u201cIt\u2019s going to be really hard,\u201d she tells me. \u201cThink of a rocky planet\u2019s atmosphere as the skin of an onion, and the whole thing is in front of, like, an IMAX screen.\u201d<\/p>\n<\/div>\n

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There\u2019s an outside chance a rocky planet orbits a star close enough for the Webb telescope to capture sufficient light to investigate it for signs of life. But most scientists, including Seager, think we\u2019ll need to wait for the next generation of space telescopes. Covering most of the wall over her vision table is a panel of micro-thin black plastic shaped like the petal of a giant flower. It\u2019s a reminder of where she\u2019s going: a space mission, still in development, that she believes can lead her to another living Earth.<\/p>\n<\/div>\n

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NEW WAYS OF SEEING\u00a0THE NEXT WAVE OF\u00a0PLANET HUNTERS<\/span><\/p>\n<\/div>\n

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The Kepler telescope, which detected thousands of exoplanets, was retired last year when it ran out of fuel, but new telescopes promise dramatic improvements in the hunt. The telescopes shown here are expected to significantly advance our ability to detect signs of habitability thousands of light-years away. In addition to a planet\u2019s size and distance from its star, they might be able to study its terrain\u00a0<\/span>and check for cloud cover.<\/span><\/p>\n<\/div>\n

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TERRESTRIAL INSTRUMENTS<\/span><\/p>\n

Ground-based scopes can hold heavy,\u00a0<\/span>powerful optics that are comparatively easy\u00a0<\/span>to maintain. But Earth\u2019s atmosphere filters\u00a0<\/span>and distorts starlight, limiting what these\u00a0<\/span>telescopes can see in outer space.<\/span><\/p>\n<\/div>\n

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SUBARU TELESCOPE<\/span><\/p>\n

Subaru Coronagraphic\u00a0<\/span>Extreme Adaptive Optics<\/span><\/em><\/p>\n

Removes distant starlight reaching the\u00a0<\/span>Subaru telescope, allowing astronomers\u00a0<\/span>to directly image exoplanets.\u00a0Aperture: 8.2 meters.\u00a0Start date: 2014<\/span><\/p>\n<\/div>\n

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ELT<\/span><\/p>\n

Extremely Large Telescope<\/span><\/em><\/p>\n

Captures visible and near-infrared\u00a0<\/span>spectrum images 16 times as sharp as those\u00a0<\/span>of the Hubble Space Telescope.<\/span><\/p>\n<\/div>\n

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Aperture: 39.3 meters.Expected start: 2024<\/span><\/p>\n<\/div>\n

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ORBITAL INSTRUMENTS<\/span><\/p>\n

Away from Earth\u2019s atmosphere, telescopes can\u00a0<\/span>detect frequencies and wavelengths across the\u00a0<\/span>electromagnetic spectrum. But they must be\u00a0<\/span>small enough to launch, and they fly too far\u00a0<\/span>away to be repaired.<\/span><\/p>\n<\/div>\n

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TESS<\/span><\/p>\n

Transiting Exoplanet Survey Satellite<\/span><\/em><\/p>\n

Detects small planets orbiting bright stars, which could be good candidates for more in-depth habitability studies.<\/span><\/p>\n<\/div>\n

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Aperture: 10.5 cm (4 cameras).\u00a0Start date: 2018.<\/span><\/p>\n<\/div>\n

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JWST<\/span><\/p>\n

James Webb Space Telescope<\/span><\/em><\/p>\n

Studies distant stars and exoplanets using\u00a0<\/span>four instruments, including infrared\u00a0<\/span>cameras and spectrographs.<\/span><\/p>\n<\/div>\n

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Aperture: 6.5 meters.\u00a0Expected start: 2021<\/span><\/p>\n<\/div>\n

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WFIRST<\/span><\/p>\n

Wide Field Infrared Survey Telescope<\/span><\/em><\/p>\n

Finds exoplanets using light warped by\u00a0<\/span>the gravity of distant stars; it could also\u00a0<\/span>be paired with Starshade.<\/span><\/p>\n<\/div>\n

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Aperture: 2.4 meters.\u00a0Expected start: 2025<\/span><\/p>\n<\/div>\n

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STARSHADE<\/span><\/p>\n

A flower-shaped light shield more than\u00a0<\/span>a hundred feet in diameter, the Starshade\u00a0<\/span>will work in tandem with a tele- scope such\u00a0<\/span>as WFIRST. It will block a host star\u2019s light, allowing astrono- mers a direct view of its exo\u00adplanets. This mission is still in development.<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n

ART DIRECTION: JASON TREAT, NGM STAFF; SEAN MCNAUGHTON
\nSOURCES: NATIONAL ASTRONOMICAL OBSERVATORY OF JAPAN; NASA; EUROPEAN SOUTHERN OBSERVATORY<\/small><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
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From an early age,<\/b> Olivier Guyon has had a problem with sleep: namely, that it\u2019s supposed to happen at night, when it\u2019s so much better to be awake. Guyon grew up in France, in the countryside of Champagne. When he was 11, his parents bought him a small telescope, which he says they later regretted. He spent many nights peering into it, only to fall asleep the next day in class. When he outgrew that telescope, he built a bigger one. But while he could magnify his view of heavenly objects, Guyon could do nothing to enlarge the number of hours in the night. Something had to give, so one day when he was a teenager, he decided to do away with sleep almost entirely. At first he felt great, but after a week or so, he became seriously ill. Recalling it now, he still shudders.<\/p>\n<\/div>\n

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At 43 years old, Guyon today has a very big telescope to work with. The Subaru observatory<\/a>, along with 12 others, sits atop the summit of Mauna Kea, on Hawaii\u2019s Big Island. The Subaru\u2019s 8.2-meter (27 feet) reflector is among the largest single-piece mirrors in the world. (Operated by the National Astronomical Observatory of Japan, the telescope has no affiliation with the car company\u2014Subaru is the Japanese name for the Pleiades star cluster.) At 13,796 feet above sea level, Mauna Kea affords one of the highest, clearest views of the universe, yet it\u2019s only an hour and a half drive from Guyon\u2019s home in Hilo. The proximity allows him to make frequent trips to test and improve the instrument he built and attached to the telescope, often working through the night. He carries around a thermos of espresso, and for a while he took to spiking it with shots of liquid caffeine, until a friend pointed out that his daily intake was more than half the lethal dose.<\/p>\n<\/div>\n

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\u201cWe can spend a couple weeks up here, and we start to forget about life on Earth,\u201d he tells me. \u201cFirst you forget the day of the week. Then you start forgetting to call your family.\u201d<\/p>\n<\/div>\n

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HOW TO FIND LIFE,\u00a0SEEKING THE LIGHT<\/span><\/p>\n<\/div>\n

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In this illustration, an exoplanet orbits in front of a star much like the sun. One way to find out if a planet might contain life is to look for telltale signs called biosignatures. As starlight reflects off a planet or passes through its atmosphere, shown here in blue, gases absorb specific wavelengths. The spectrum observed through a telescope could show whether gases associated with life, such as oxygen, carbon dioxide, or methane, are present.<\/span><\/p>\n<\/div>\n

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Earth\u2019s gaseous signs of life<\/span><\/p>\n

Electromagnetic energy (light) passing through the atmosphere would create a spectrum like this one, which shows the presence of compounds linked to life.<\/span><\/p>\n<\/div>\n

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Spectral radiance,\u00a0Ozone,\u00a0Water,\u00a0Carbon,\u00a0dioxide,\u00a0Methane,\u00a0Wavelength<\/span><\/p>\n<\/div>\n

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SEEING THE COLORS<\/span><\/p>\n<\/div>\n

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On Earth, chlorophyll in photosynthesizing plants absorbs red and blue light, so vegetation appears green. On other living worlds, though, photosynthesis might use a different pigment. The lavender hue of this hypothetical exoplanet, viewed from its icy moon, derives from a pigment called retinal, which is also able to convert light to metabolic energy and may have preceded chlorophyll in Earth\u2019s early history.<\/span><\/p>\n<\/div>\n

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Earth\u2019s chromatic signs of life<\/span><\/p>\n

A sharp contrast in a spectrum between the absorption of red light and reflection of near-infrared light, known as the vegetation red edge, indicates the presence of plants.<\/span><\/p>\n<\/div>\n

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Vegetation,\u00a0red edge,\u00a0Reflectivity.\u00a0Lichen,\u00a0Lodgepole,\u00a0pine,\u00a0Red,\u00a0algae,\u00a0Wavelength<\/span><\/p>\n<\/div>\n

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INTELLIGENT ALIENS<\/span><\/p>\n<\/div>\n

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Until now, the search for extraterrestrial intelligence has focused on detecting an incoming radio signal. With increasing computational power and more sensitive telescopes, researchers are expanding the search to optical and infrared emissions, targeting the \u201ctechnosignatures\u201d of advanced civilizations. These could include laser pulses, polluting gases, or megastructures built around a nearby star to harness its energy.<\/span><\/p>\n<\/div>\n

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Transmission spikes from space<\/span><\/p>\n

This power spectrum from a survey of 14 planetary systems included a signal that looked promising, but no evidence was found that it was created by intelligent life.<\/span><\/p>\n<\/div>\n

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Radio power,\u00a0-500,\u00a00,\u00a0500.<\/span><\/p>\n<\/div>\n

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Frequency offset (Hz)<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

ART DIRECTION: JASON TREAT, NG STAFF: SEAN MCNAUGHTON
\nSOURCES: EDWARD W. SCHWIETERMAN, UC RIVERSIDE (ALL); BREAKTHROUGH INITIATIVES; SETI INSTITUTE (INTELLIGENT ALIENS)<\/small><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n
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Like Seager, Guyon is a MacArthur winner. His particular genius is in the mastery of light: how to massage and manipulate it to catch a glimpse of things that even the Subaru\u2019s huge mirror would be blind to without Guyon\u2019s legerdemain.<\/p>\n<\/div>\n

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\u201cThe big question is whether there is biological activity up there,\u201d he says, pointing at the sky. \u201cIf yes, what is it like? Are there continents? Oceans and clouds? All these questions can be answered, if you can extract the light of a planet from the light of its star.\u201d<\/p>\n<\/div>\n

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In other words, if you can see<\/i> the planet. Trying to separate the light of a rocky, Earth-size planet from that of its star is like squinting hard enough to make out a fruit fly hovering inches in front of a floodlight. It doesn\u2019t seem possible, and with today\u2019s telescopes, it isn\u2019t. But Guyon has his sights set on what the next generation of ground-based telescopes might be able to do, if they can be fashioned to squint very, very hard.<\/p>\n<\/div>\n

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That is precisely what his instrument is designed to do. The apparatus is called\u2014brace yourself\u2014the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO, pronounced \u201cskex-a-o\u201d). Guyon wanted me to see it in action, but a power outage had shut down the Subaru. Instead he offers to give me a tour of the 141-foot dome enclosing the telescope. There is 40 percent less oxygen here than at sea level. Visitors have the option of strapping on some bottled oxygen, but he decides that I don\u2019t need any, and off we go.<\/p>\n<\/div>\n

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\u201cI was giving a tour the other day to some scientists, and all of a sudden, one of them fainted!\u201d he says, with a mixture of surprise and regret. \u201cI should have known she was not doing well. She had gotten very quiet.\u201d I clutch the railings and make sure to keep asking questions.<\/p>\n<\/div>\n

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MAPPING EXOPLANETS, HUNTING FOR HABITABILITY<\/span><\/p>\n<\/div>\n

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Earth supports life in part because its terrain\u00a0is rocky, it doesn\u2019t receive too much solar\u00a0radiation, and its distance from the sun allows water to be in a liquid state. So far, 47\u00a0exoplanets have been found that fit this\u00a0profile. But that number will grow as new\u00a0telescopes search for planets in broader\u00a0swaths of the galaxy than ever before.\u00a0Scientists use our solar system to help determine the habitable zone around a star.<\/span><\/p>\n

To support life, planets must receive no\u00a0more energy from their stars than Venus\u00a0did when it had liquid surface water and no\u00a0less energy than Mars did when it had water.<\/span><\/p>\n<\/div>\n

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Planet size<\/span><\/p>\n<\/div>\n

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1\/2 Earth, Earth\u2019s diameter, (7,926<\/span> miles), 2X Earth. Planets in the habitable zone more likely to have liquid surface water. Planets in the habitable zone, 6,600 Kelvin, Hot, Venus, Mars<\/span><\/p>\n<\/div>\n

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EARTH<\/span><\/p>\n<\/div>\n

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Temperature\u00a0of host star, 2,200, Kelvin, Cool, Proxima b, 4.2 light-years from Earth. Radiation from host star received by exoplanet. No radiation received. Twice the radiation received by Earth.<\/span><\/p>\n<\/div>\n

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IMPROVING THE HUNT<\/span><\/p>\n

Launched last year, the TESS space telescope\u00a0is now fully operational. It is able to survey 85\u00a0percent of the night sky, an area 400 times as\u00a0large as that covered by its predecessor, Kepler.\u00a047.\u00a0<\/span>Potentially habitable exoplanets.\u00a0More than 3,800 <\/span>known exoplanets. Approximately 4,400 Additional exoplanets TESS is expected to discover.<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

ART DIRECTION: JASON TREAT, NGM STAFF
\nSOURCES: PLANETARY HABITABILITY LABORATORY; ABEL M\u00c9NDEZ, UNIVERSITY OF PUERTO RICO AT ARECIBO; TOM BARCLAY, NASA<\/small><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n
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Ground telescopes like the Subaru are much more powerful light-gatherers than space telescopes like the Hubble<\/a>, chiefly because nobody has yet figured out how to squeeze a 27-foot mirror into a rocket and blast it into space. But ground telescopes have a serious drawback: They sit under miles of our atmosphere. Fluctuations in the air\u2019s temperature cause light to bend erratically\u2014think of a twinkling star, or the wavy air above an asphalt road in the summertime.<\/p>\n<\/div>\n

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The first task of the SCExAO is to iron out those wrinkles. This is accomplished by directing the light from a star onto a shape-shifting mirror, smaller than a quarter, activated by 2,000 tiny motors. Using information from a camera, the motors deform the mirror 3,000 times a second to precisely counter the atmospheric aberrations, and voil\u00e0,<\/i> a beam of starlight can be viewed that is as close as possible to what it was before our atmosphere messed it up. Next comes the squinting part. To Guyon, a star\u2019s luminosity is \u201ca boiling blob of light that we\u2019re trying to get rid of.\u201d His instrument includes an intricate system of apertures, mirrors, and masks called a coronagraph, which allows only the light reflected off the planet to slip through.<\/p>\n<\/div>\n

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There\u2019s a great deal more to the apparatus; staring at a schematic of the device is enough to cause vertigo, even at sea level. But the eventual result, once the next-gen telescopes are built, will be a visible dot of light that is actually a rocky planet. Shunt this image to a spectrometer, a device that can parse light into its wavelengths, and you can start dusting it for those fingerprints of life, called biosignatures.<\/p>\n<\/div>\n

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There\u2019s one biosignature that Seager, Guyon, and just about everyone else agree would be as near a slam dunk for life as scientific caution allows. We already have a planet to prove it. On Earth, plants and certain bacteria produce oxygen as a by-product of photosynthesis. Oxygen is a flagrantly promiscuous molecule\u2014it\u2019ll react and bond with just about everything on a planet\u2019s surface. So if we can find evidence of it accumulating in an atmosphere, it will raise some eyebrows. Even more telling would be a biosignature composed of oxygen and other compounds related to life on Earth. Most convincing of all would be to find oxygen along with methane, because those two gases from living organisms destroy each other. Finding them both would mean there must be constant replenishment.<\/p>\n

It would be grossly geocentric, however, to limit the search for extraterrestrial life to oxygen and methane. Life could take forms other than photosynthesizing plants, and indeed even here on Earth, anaerobic life existed for billions of years before oxygen began to accumulate in the atmosphere. As long as some basic requirements are met\u2014energy, nutrients, and a liquid medium\u2014life could evolve in ways that would produce any number of different gases. The key is finding gases in excess of what should be there.<\/p>\n<\/div>\n

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The solar sail for NASA\u2019s Near-Earth Asteroid (NEA) Scout, a robotic reconnaissance mission designed to fly by asteroids, easily fits into a CubeSat (left) that\u2019s just 12 inches long. Principal investigator Les Johnson (right) floats a scrap of the aluminized plastic sail material, which is much thinner than a human hair.<\/span><\/div>\n
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There are other sorts of biosignatures we can look for too. The chlorophyll in vegetation reflects near-infrared light\u2014the so-called red edge, invisible to human eyes but easily observable with infrared telescopes. Find it in a planet\u2019s biosignature, and you may well have found an extraterrestrial forest. But the vegetation on other planets might absorb different wavelengths of light\u2014there could be planets with Black Forests that are truly black, or planets where roses are red, and so is everything else.<\/p>\n<\/div>\n

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And why stick to plants? Lisa Kaltenegger, who directs the Carl Sagan Institute at Cornell University<\/a>, and her colleagues have published the spectral characteristics of 137 microorganisms, including ones in extreme Earth environments that, on another planet, might be the norm. It\u2019s no wonder the next generation of telescopes is so eagerly anticipated.<\/p>\n<\/div>\n

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\u201cFor the first time, we\u2019ll be able to collect enough light,\u201d says Kaltenegger. \u201cWe\u2019ll be able to figure things out.\u201d<\/p>\n<\/div>\n

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The first and most powerful of the next-gen ground telescopes, the European Southern Observatory\u2019s eponymous Extremely Large Telescope (ELT) in the Atacama Desert of Chile<\/a>, is scheduled to start operation in 2024. The light-gathering capacity of its 39-meter (128 feet) mirror will exceed all existing Subaru-size telescopes combined. Outfitted with a souped-up version of Guyon\u2019s instrument, the ELT will be fully capable of imaging rocky planets in the habitable zone of red dwarf stars, the most common stars in the galaxy. They are smaller and dimmer than our sun, a yellow dwarf, so their habitable zones are closer to the star. The nearer a planet is to its star, the more light it reflects.<\/p>\n<\/div>\n

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Alas, the habitable zone of a red dwarf star is not the coziest place in the galaxy. Red dwarfs are highly energetic, frequently hurtling flares out into space as they progress through what Seager calls a period of \u201cvery long, bad, teenage behavior.\u201d There might be ways an atmosphere could evolve that would protect nascent life from being fried by these solar tantrums. But planets around red dwarfs are also likely to be \u201ctidally locked\u201d\u2014always presenting one side to the star, in the same way our moon shows only one face to the Earth. This would render half the planet too hot for life, the other half too cold. The midline, though, might be temperate enough for life.<\/p>\n<\/div>\n

As it happens, there\u2019s a rocky planet, called Proxima Centauri b<\/a>, orbiting in the habitable zone of Proxima Centauri, a red dwarf that\u2019s the nearest star to our own, about 4.2 light-years, or 25 trillion miles, away. \u201cIt\u2019s a terribly exciting target,\u201d Guyon says. But he agrees with Seager that the best chance of finding life will be on an Earth-like planet orbiting a sunlike star. The ELT and its ilk will be fantastic at gathering light, but even those behemoth ground telescopes won\u2019t be able to separate the light of a planet from that of a star 10 billion times brighter.<\/div>\n
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NEW WAYS OF SEEING, PROPELLED BY LIGHT<\/span><\/p>\n<\/div>\n

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Breakthrough Starshot is an ambitious plan in development to send tiny probes on a 20-year journey to the exoplanet Proxima Centauri b. But even a featherweight spacecraft needs fuel. The farther it goes, the more it needs. The proposed solution? Forget fuel: Launch it from an orbiting satellite and propel it with Earth-based lasers.<\/span><\/p>\n<\/div>\n

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The mother ship<\/span><\/p>\n

Situated in low Earth orbit, a satellite\u00a0houses thousands of probes. When\u00a0the individual probes are released,\u00a0their sails automatically unfurl.<\/span><\/p>\n<\/div>\n

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Phased lasers<\/span><\/p>\n

On Earth, nearly a billion laser beams\u00a0are directed at a probe to create a\u00a0pulse with the power of 100 gigawatts, lasting several minutes.<\/span><\/p>\n<\/div>\n

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Going interstellar<\/span><\/p>\n

Those few minutes are just enough to\u00a0accelerate the probe to one-fifth the speed of light and into the vacuum of space, where it is able to glide.<\/span><\/p>\n<\/div>\n

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First contact<\/span><\/p>\n

The probe reaches Proxima b\u00a0after a voyage of more than 20 years.\u00a0During its high-speed flyby, it takes images and records a range of data.<\/span><\/p>\n<\/div>\n

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Phoning home<\/span><\/p>\n

The probe beams the information\u00a0back using a laser embedded in its\u00a0chip. Each transmission takes about\u00a0four years to reach the Earth.<\/span><\/p>\n<\/div>\n

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Each probe has a quarter-inch chip weighing five grams or less that performs the roles of a camera, computers, and\u00a0navigational equipment.<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n

ART DIRECTION: JASON TREAT, NGM STAFF; SEAN MCNAUGHTON
\nSOURCES: BREAKTHROUGH INITIATIVES; ZAC MANCHESTER, STANFORD UNIVERSITY<\/small><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
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Left: <\/span>To reach Alpha Centauri, our nearest neighboring star system, the Breakthrough Starshot initiative proposes to launch a fleet of tiny spacecraft, each weighing a gram or less, and accelerate them to a fifth the speed of light by a blast from a gigantic ground-based laser array. The smallest existing\u2026\u00a0Read More<\/span><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
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Breakthrough Starshot team member and Stanford University researcher Zac Manchester developed the Sprite at NASA Ames in Mountain View, California. If all of the components of the Breakthrough Starshot project can be realized, the space fleet would reach Alpha Centauri in 20 years after launch. \u201cIt\u2019s not science fiction,\u201d Manchester says. \u201cit\u2019s just engineering.\u201d<\/div>\n<\/figcaption><\/figure>\n
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That\u2019s going to take a little more time and even more exotic\u2014one might even say dreamlike\u2014technology. Remember that flower petal\u2013shaped panel on Seager\u2019s wall? It\u2019s a piece of a space instrument called Starshade. Its design consists of 28 panels arranged around a center hub like a giant sunflower, more than 100 feet across. The petals are precisely shaped and rippled to deflect the light from a star, leaving a super-dark shadow trailing behind. If a telescope is positioned far back in that tunnel of darkness, it will be able to capture the glimmer from an Earth-like planet visible just beyond the Starshade\u2019s edge.<\/p>\n<\/div>\n

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Starshade\u2019s earliest likely partner is called the Wide Field Infrared Survey Telescope (WFIRST), scheduled to be finished by the mid-2020s. The two spacecraft will work together in a sort of celestial pas de deux:<\/i> Starshade will amble into position to block the light from a star so WFIRST can detect any planets around it and potentially sample their spectra for signs of life. Then, while WFIRST busies itself with other tasks, Starshade will fly off into position to block the light of the next star on its list of targets. Though the dancers will be tens of thousands of miles apart, they must be aligned to within a single meter for the choreography to work.<\/p>\n<\/div>\n

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Starshade, under development at NASA\u2019s Jet Propulsion Laboratory in Pasadena, California, is still a decade or so away, and indeed there\u2019s no guarantee that it will be funded. Seager, who hopes to lead the project, is confident. One can only hope. There\u2019s something uniquely uplifting about the prospect of a giant flower in space unfurling its petals to parry the light from a distant sun to see if its orbiting worlds are alive.<\/p>\n<\/div>\n

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A laser transmitter, like this one developed by II-VI, Inc. and the University of Dayton, presages the technology that Breakthrough Starshot needs to propel spacecraft to the nearest star. Laser beams from the device\u2019s 21 lenses converge on a remote target. Starshot\u2019s laser array will combine close to a billion similar beams.<\/div>\n<\/figcaption><\/figure>\n
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When Jon Richards<\/b> answered an ad in 2008 on Craigslist for a software programmer, he couldn\u2019t have imagined he would spend much of the next 10 years in a remote valley in Northern California, looking for aliens. The search for extraterrestrial intelligence, or SETI, refers to both a research endeavor and a nonprofit organization, the SETI Institute, which employs Richards to run the Allen Telescope Array (ATA), a 340-mile drive from the institute\u2019s headquarters in Silicon Valley. The ATA is the only facility on the planet built expressly for detecting signals from alien civilizations. Funded largely by the late Microsoft co-founder Paul Allen, it was envisioned as an assembly of 350 radio telescopes, with dishes six meters (20 feet) in diameter. But owing to funding difficulties\u2014a regrettable leitmotif in SETI history\u2014only 42 have been built. At one time seven scientists helped run the ATA, but due to attrition, Richards is \u201cthe last man standing,\u201d as he gamely puts it.<\/p>\n<\/div>\n

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I\u2019ve come to see Richards on a hot day in August, soon after a rash of wildfires in the area. Smoke veils the view of the surrounding mountains, and in the haze the dishes seem primordially still, like Easter Island statues, each one staring implacably at the same spot in a featureless sky. Richards takes me to one of the dishes, opening the bay doors beneath it to reveal its newly installed antenna feed: a crenellated taper of shiny copper housed in a thick glass cone. \u201cLooks kinda like a death ray,\u201d he says.<\/p>\n<\/div>\n

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Richards\u2019s job is to manage the hardware and software, including algorithms developed to sift through the several hundred thousand radio signals streaming into the telescopes every night, in search of a \u201csignal of interest.\u201d Radio frequencies have been the favored hunting ground of SETI since the search for alien transmissions began 60 years ago, largely because they travel most efficiently through space. SETI scientists have focused in particular on a quiet zone in the radio spectrum, free of background noise from the galaxy. It made sense to search in this relatively undisturbed range of frequencies, since that would be where sensible aliens would be most likely to transmit.<\/p>\n<\/div>\n

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SETI Institute Senior Software Engineer Jon Richards works on one of the units in the Allen Telescope Array, the only facility on Earth built specifically to look for signs of extraterrestrial intelligence.The telescope array, located in the Cascade mountains in Northern California, was supposed to have 350 radio telescopes, but because of funding difficulties, only 42 have been built.\u00a0Richards inspects an antenna feed in one of the ATA\u2019s units. The hope is to find an anomalous signal: one emanating neither from a natural source in the cosmos, nor from earthly interference, such as a satellite or airplane.\u00a0Radio emissions captured by the ATA\u2019s dishes are focused onto the feed, which then amplifies the signals, digitizes them, and sends them via a fiber optic cable to the facilities\u2019 signal-processing room.<\/picture><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/figure>\n<\/div>\n
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Richards tells me that the ATA is working through a target list of 20,000 red dwarfs. In the evening, he makes sure everything is working properly, and while he sleeps, the dishes point, the antennas rouse, photons scuttle through fiber optic cables, and the radio music of the cosmos streams to enormous processors. If a signal passes tests that suggest it stems from neither a natural source nor some quotidian terrestrial one\u2014a satellite, a plane, somebody\u2019s key fob\u2014the computer kicks out an email alert. This being an email he wouldn\u2019t want to miss, Richards has set up his cell service to forward the message to his phone. Conceivably, then, our first contact from an alien civilization could come as a text rattling Richards\u2019s phone on his night table.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
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So far, however, all the signals of interest have been false alarms. Unlike other experiments, where progress can be made incrementally, SETI is binary: Either extraterrestrials make contact on your watch, or they don\u2019t. Even if they\u2019re out there, the chances that you\u2019re looking in just the right place at just the right time and at just the right radio frequency are remote. Jill Tarter, the retired head of research at SETI, likens the search to dipping a cup in the ocean: The chance you\u2019ll find a fish is exceedingly small, but that doesn\u2019t mean the ocean isn\u2019t full of fish. Unfortunately, Congress long ago lost interest in dipping the cup, abruptly terminating support in 1993.<\/p>\n<\/div>\n

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The good news <\/b>is that SETI the research endeavor, if not SETI the institute, has recently received a remarkable boost in funding, sending ripples of excitement through the field. In 2015 Yuri Milner, a Russian-born venture capitalist, established the Breakthrough Initiatives, committing at least $200 million to look for life in the universe, including $100 million specifically to search for alien civilizations. Milner was an early investor in Facebook, Twitter, and many other internet companies you wish you\u2019d been an early investor in. Before that, he founded a highly successful internet company in Russia. His philanthropic vision might be summed up as, if we agree that finding evidence for alien intelligence is worth $100 million, why shouldn\u2019t it be his $100 million? \u201cIf you look at it that way, it makes sense,\u201d he says, when I meet him in a glitzy watering hole in Silicon Valley. \u201cIf it was a billion a year\u2014we should talk.\u201d<\/p>\n<\/div>\n

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Laurance Doyle of Principia College and the SETI Institute communes with some \u201cextraterrestrial\u201d intelligence at Six Flags Discovery Kingdom in Vallejo, California. Doyle\u2019s studies of the communication systems of dolphins and whales could help scientists decode patterns in alien languages.<\/div>\n<\/figcaption><\/figure>\n
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Milner is soft-spoken and unobtrusive; I hadn\u2019t noticed him arrive until he was standing right next to my chair. He tells me about his background\u2014a degree in physics, a lifelong passion for astronomy, and parents who named him after the cosmonaut Yuri Gagarin, who became the first human in outer space seven months before Milner was born. That was in 1961, which he points out is the same year SETI began. \u201cEverything is interrelated,\u201d he says.<\/p>\n<\/div>\n

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Through one of his initiatives, Breakthrough Listen, he intends to spend $100 million over 10 years, most of it through the SETI Research Center at UC Berkeley. Another project, Breakthrough Watch, is underwriting new technology to search for biosignatures with the European Southern Observatory\u2019s Very Large Telescope in Chile.<\/p>\n<\/div>\n

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Most far out of all\u2014in both senses\u2014is Milner\u2019s Breakthrough Starshot, which is investing $100 million to explore the feasibility of actually going to the nearest star system, Alpha Centauri, which includes the rocky planet Proxima b. Appreciating the magnitude of this challenge requires some perspective. The first Voyager spacecraft, launched in 1977, took 35 years to enter interstellar space. Traveling at that speed, Voyager would need some 75,000 years to reach Alpha Centauri. In the current vision for Starshot, a fleet of pebble-size spaceships hurtling through space at one-fifth the speed of light could reach Alpha Centauri in a mere 20 years. Working from a road map originally proposed by physicist Philip Lubin at UC Santa Barbara, these tiny Ni\u00f1as, Pintas, <\/i>and Santa Mar\u00edas<\/i> would be propelled by a ground-based laser array, more powerful than a million suns. It may not be possible. But that\u2019s the advantage of private money: Unlike a government program, you\u2019re allowed\u2014expected\u2014to take a big gamble.<\/p>\n<\/div>\n

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\u201cLet\u2019s see in five or 10 years whether it will work,\u201d Milner says, with a shrug. \u201cI\u2019m not an enthusiast in the sense I believe for sure any of this will happen. I\u2019m an enthusiast because it makes sense now to try.\u201d<\/p>\n<\/div>\n

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SETI Institute scientists, funded by NASA, gather data in the Chilean desert that will inform the search for life on Mars. Domes dotting the seemingly lifeless landscape host microbes that thrive in the harsh climate. \u201cIt is full of life, absolutely everywhere,\u201d says team leader Nathalie Cabrol.<\/div>\n<\/figcaption><\/figure>\n
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The Salar de Pajonales, a dry gypsum lake bed in the Chilean Altiplano, is one of the most inhospitable places on Earth\u2014and an excellent analogue for an ancient Martian lake. The SETI Institute\u2019s NASA Astrobiology Institute Team is developing methods, including drilling, to look for signs of ancient life on Mars.<\/div>\n<\/figcaption><\/figure>\n
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While the landscape appears lifeless, microbes thrive in pockets in the gypsum where water is trapped. \u201cIn the desert you realize that all the global information we have about planet Earth and its climate gives us very few clues about where these microbial habitats are located, and why,\u201d Cabrol says. \u201cYou have to become the microbe, start thinking in the scale of the microbe.\u201d<\/div>\n<\/figcaption><\/figure>\n
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The day after meeting with Milner, I went to the Berkeley campus to meet the beneficiaries of his Breakthrough Listen largesse. Andrew Siemion, the director of the Berkeley SETI Research Center, is ideally positioned to take the search for intelligent aliens to a new level. In addition to his Berkeley appointment, he has been named to head up SETI investigations at the SETI Institute itself, including operations at the ATA.<\/p>\n<\/div>\n

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Siemion, 38, looks the part of a next-gen SETI master; he has a shaved head, a compact build, and a thin gold chain discreetly visible above the buttons of his fitted shirt. While careful to credit the decades of research by Tarter and her colleagues at the SETI Institute, he\u2019s keen to distinguish where SETI is going from where it has been. The initial search was inspired by the possibility of a connection\u2014reaching out in hope of finding someone reaching back. SETI 2.0 is trying to determine whether technological civilization is part of the cosmic landscape, like black holes, gravitational waves, or any other astronomical phenomenon.<\/p>\n

\u201cWe\u2019re not looking for a signal,\u201d Siemion says. \u201cWe\u2019re looking for a property of the universe.\u201d<\/p>\n<\/div>\n

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Breakthrough Listen is by no means abandoning the conventional search for radio transmissions, he tells me; on the contrary, it\u2019s doubling down on it, dedicating to SETI roughly a quarter of the viewing time on two huge single-dish radio telescopes in West Virginia and Australia. Siemion is even more excited about a partnership with the new MeerKAT telescope in South Africa, an array of 64 radio dishes, each more than twice the size of the ATA\u2019s. By piggybacking on observations conducted by other scientists, Breakthrough Listen will conduct a 24\/7 stakeout of a million stars, dwarfing previous SETI radio searches. Powerful as it is, MeerKAT is just a precursor to radio astronomy\u2019s dream machine: the Square Kilometre Array, which sometime in the next decade will link hundreds of dishes in South Africa with thousands of antennas in Australia, creating the collecting area of a single dish more than a square kilometer, or about 247 acres.<\/p>\n<\/div>\n

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There are other SETI approaches Siemion tells me about\u2014Breakthrough Listen partnerships with telescopes in China, Australia, and the Netherlands, and new technologies in development at Berkeley, the SETI Institute, and elsewhere to look for optical and infrared signals. The gist, echoed by other scientists I talk with, is that SETI is undergoing a transformation from cottage industry to global enterprise.<\/div>\n<\/header>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
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Most important, empowered and inspired by the accelerating rate of technological development in our own civilization, we are coming to see the target of the quest in a different light. For 60 years we\u2019ve been waiting for ET to phone Earth. But the stark truth is that ET probably has no compelling reason to try to communicate with us, any more than we feel a heartfelt need to extend a greeting to a colony of ants. We may feel technologically mature compared with our past, but compared with what may be out there in the universe, we\u2019re still in diapers. Any civilization that we would be able to detect will likely be millions, perhaps billions, of years ahead of us.<\/p>\n<\/div>\n

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\u201cWe\u2019re like trilobites, looking for more trilobites,\u201d says Seth Shostak, a senior astronomer at the SETI Institute.<\/p>\n<\/div>\n

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What we should be looking for is not a message from ET, but signs of ET just going about the business of being ET, alien and intelligent in ways that we may not yet comprehend but may still be able to perceive, by looking for evidence of technology\u2014so-called technosignatures.<\/p>\n<\/div>\n

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The most obvious technosignatures would be ones we\u2019ve produced, or can imagine producing, ourselves. Avi Loeb of Harvard University, who chairs the Breakthrough Starshot advisory board, has noted that if another civilization were using similar laser propulsion to sail through space, its Starshot-like beacons would be visible to the edge of the universe. Loeb also has suggested looking for the spectral signatures of chlorofluorocarbons soiling the atmosphere of aliens who failed to live past the technological diaper stage.<\/p>\n<\/div>\n

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\u201cBased on our own behavior, there must be many civilizations that killed themselves by harnessing technologies that led to their own destruction,\u201d he tells me when I visit him. \u201cIf we find them before we destroy our own planet, that would be very informative, something we could learn from.\u201d<\/p>\n<\/div>\n

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On a cheerier note, we could learn a great deal more from civilizations that have solved their energy problem. At a NASA conference on technosignatures (yes, after a quarter century, NASA too is getting back into the SETI game), there was talk about looking for the waste heat from megastructures that we have imagined creating in the future. A Dyson sphere\u2014solar arrays surrounding a star and capturing all of its energy\u2014around our own sun would generate enough power in a second to supply our current demand for a million years. Learning that other civilizations have already accomplished such feats might provide us some hope.<\/p>\n

Still, space is vast, and so is time. Even with our ever more powerful computers and telescopes, SETI\u2019s expanded agenda, and the gravity assist of a hundred Yuri Milners, we may never encounter an alien intelligence. On the other hand, the first intimation of life from a distant planet feels thrillingly close.<\/p>\n<\/div>\n

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\u201cYou never know what\u2019s going to happen,\u201d Seager says. \u201cBut I know that something great is around those stars.\u201d<\/p>\n

Contributing writer Jamie Shreeve<\/b> bets we\u2019ll find hints of extraterrestrial life before 2030. Spencer Lowell<\/b> has constellations tattooed on one arm. Dana Berry<\/b> has imagined unseen scenes in space<\/a> for National Geographic and other publications.<\/em><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

NASA\u2019s James Webb Space Telescope, National Geographic   We have reminded at times of the need to reflect on our place, as humans, and the place of planet earth and all life on it, in the larger universe. The new issue of the National Geographic Magazine takes us through a journey extroardinaire, by words, photos […]<\/p>\n","protected":false},"author":1001004,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[54],"tags":[],"_links":{"self":[{"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/posts\/6360"}],"collection":[{"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/users\/1001004"}],"replies":[{"embeddable":true,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6360"}],"version-history":[{"count":3,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/posts\/6360\/revisions"}],"predecessor-version":[{"id":6385,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=\/wp\/v2\/posts\/6360\/revisions\/6385"}],"wp:attachment":[{"href":"https:\/\/worldcampaign.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6360"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6360"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/worldcampaign.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6360"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}