SETI Turns Radio Telescopes Toward Kepler Candidate Planets, Listening for Signs of Life

Listening to places where conditions are right for life

By Rebecca Boyle

From http://www.popsci.com/

Is There Anybody Out There? The Robert C. Byrd Green Bank Telescope, the world's largest fully steerable radio telescope, is listening to 86 Kepler candidate Earth-like planets in the hopes of hearing from alien life. Wikimedia Commons

A gigantic radio telescope in Virginia has started listening to 86 Earth-like planet candidates identified by the Kepler Space Telescope, hoping to hear signs of alien life. Astronomers aren’t even sure the stars to which they are listening actually harbor planets, let alone radio-communicating extraterrestrials, but hey, we might as well bend an ear, right?

The SETI Institute is looking at Earth-like (rocky) planets with a focus on those with temperatures between 0 and 100 °C (32° and 212 °F), where liquid water can exist. As far as our Earth-biased science can tell us, that’s a crucial ingredient for life.SETI has been listening to parts of the sky for decades, but pointing directly at Kepler findings stands among the project’s best-informed attempts yet. The Arecibo telescope in Puerto Rico looks at stars like the sun, hoping they might have planets around them.

“But we’ve never had a list of planets like this before,” said physicist Dan Werthimer, director of the SETI project at Arecibo, in an interview with AFP.

In February, Kepler scientists announced they had found 1,235 potential planets orbiting sun-like stars in the Milky Way, including 68 approximately Earth-size and 288 super-Earth-size. Scientists have been verifying and refining the measurements in the months since.

The Robert C. Byrd Green Bank Telescope will gather 24 hours of data on each of 86 planets identified this spring by the Kepler space telescope science team as potential Earth-like planets in “Goldilocks” orbits, where conditions are neither too hot nor too cold for liquid water.

SETI has its own telescopes, too, but apparently they’ve gone dark for a lack of funding, according to the AFP — SETI announced last month it was shutting down its 42-dish Allen Telescope Array because of a budget shortfall, AFP reports. While the 4-year-old, $50 million project is on hiatus, the Green Bank telescope will assume its responsibilities.

While Arecibo will also keep listening, Green Bank can hear a lot more — it scans 300 times the range of frequencies that Arecibo can, so it can collect as much data in one day as Arecibo could in one year.

The Kepler listening project will take about a year, AFP reports. SETI@home users will help crunch the data; the program uses small bits of unused processing power from idle Internet-connected computers to run calculations. You can find out more, and sign up to help, by clicking here.

[AFP]

Seti: The hunt for ET

Scientists have been searching for aliens for 50 years, scanning the skies with an ever-more sophisticated array of radio telescopes and computers. Known as Seti, the search marks its half-century this month. Jennifer Armstrong and Andrew Johnson examine its close – and not so close – encounters

Rex

Scientists have been searching for aliens for 50 years

E.T., Why Don't You Just Call?

Scientists have started to scan the heavens with a new telescope that searches for signs of extraterrestrial intelligence 24 hours a day, seven days a week.

(Courtesy Seth Shostak, Senior Astronomer, SETI Institute)

New Tools Help in Search for Extraterrestrial Intelligence

OPINION By LEE DYE

June 3, 2009 —

An innovative new radio telescope has given new life to the search for extraterrestrial intelligence, leading one of the leaders of the search to make a bold prediction.

"We'll find ET within two dozen years," Seth Shostak, senior astronomer at the SETI Institute, proclaimed in a speech at the California Institute of Technology. Shostak went on to say that he not only has a pretty good hunch about how long it could take, he thinks he knows what ET will be like.

But don't expect him to look like us.

"I think that if there's a conscious intelligence out there, it's synthetic," Shostak added. He's talking robots, folks. The argument goes like this: Darwinian evolution is a very slow process, and although it probably has occurred on many planets, it has it's limitations -- like us. Technological evolution, by contrast, can advance at warp speed, as we've all seen in the computers that are out of date by the time we get them out of the box.

Thus, any biological life, like us, will eventually lose out to the machines we create, and synthetic intelligence will take over where we leave off. The real challenge, of course, will be to keep the robots under control but still let them do our thinking for us, a neat trick if we can pull it off.

It's probably going to happen, Shostak said, because technological evolution "just blows Darwin away." So, ET not only should be out there someplace, he should be one really smart machine.

Now, predictions about how long it will take to find ET are not rare, since that's probably the most common question put to scientists at the SETI Institute, a private, nonprofit organization dedicated to the search for intelligent life elsewhere in the galaxy. The institute has been the largest player in the search since NASA abandoned a formal program several years ago. The space agency has continued searching for other Earth-like planets, including the launching of the Kepler telescope last March, but it has shied away from looking directly for ET.

What makes the search different now is the creation of the Allen Telescope Array in a dusty valley 290 miles northeast of San Francisco that will, for the first time, look for ET 24 hours a day, seven days a week. Only 42 of the planned 350 radio dishes that will make up the array have been completed, but that's enough for scientists to begin combing the heavens for many secrets, including the hiding place of ET.

The array is a joint project by the University of California, Berkeley, and the SETI Institute. The primary financial support has come from Paul Allen, co-founder of Microsoft, who put up $25 million in seed money in 2001.

The array is the first panchromatic, wide-angle, snapshot radio camera ever built, according to scientists at Berkeley. The design is based on the idea that it's cheaper to build a lot of small radio antennas that act as one than it is to build huge dishes.

As part owner of the new array, SETI finally has its own toolbox and scientists will no longer be forced to use "other people's telescopes, which is like doing cancer research with borrowed microscopes," Shostak said.

Shostak's optimism is based partly on the availability of the array, and partly on the fact that new planets are being discovered outside our solar system on about a monthly basis. They are not all capable of sustaining life as we know it, but some of them may be. That has lead many scientists to speculate that life, and possibly intelligent life, abounds throughout the universe.

But that contributes to one of the debates that have plagued SETI over the years. If there are lots of other planets out there like ours, with living creatures that are at least smart enough to build radio transmitters, why haven't we found them? SETI may not have had all the tools it needed, and funding has been scarce, but lots of very smart people have been looking very hard for ET for several decades.

Some astronomers dismiss those questions by noting that there's just zillions of places to look, and they are a long ways away, and no one is certain what to look for. So in the past, searchers have counted on finding radio signals that are beamed our way by someone on another planet who is looking for us.

It would probably have to be a directed beam because "leakage," like from television broadcasts, would be too weak. Besides, why would someone who is so much smarter than us broadcast over the air when fiber optics are more reliable and efficient? Our own electromagnetic signature is shrinking, Shostak noted in his talk, so we're not likely to stumble across ET's version of "ABC News with Charles Gibson."

But new tools, including the Allen Telescope Array, could open new ways to search for ET. Unlike other radio telescopes, the array can image a huge piece of the sky at once, or concentrate on a single star with an interesting planetary system. All objects in space emit radio waves, which can reveal much about their composition.

One way to narrow the search is to look for some of the things produced on Earth that would not be here if there had been no life. Methane, Shostak noted, would disappear from a planet's atmosphere in a relatively short time, so if it's there, something must be producing it.

"Much of the methane in this room is produced by what is politely called 'bovine flatulence,' and also by porcine flatulence, so this technique would at least allow you to find pigs in space," he added. But, of course, they would not necessarily be smart pigs.

It is widely believed that water would have to be present on another planet for it to support life, and scientists at the University of Washington have devised a technique that they say would determine if another planet has oceans. Using instruments aboard a NASA spacecraft, the scientists studied light intensities from Earth in seven bands of visible light from near ultraviolet to near infrared.

They found two dominant colors, blue and red, and surmised that the red came from land masses, and the blue from oceans. If they could detect the same colors from a distant planet, they would have evidence that the planet had huge areas of water, the scientists said in an article that is scheduled for publication in Astrophysical Journal.

"Liquid water on the surface of a planet is the gold standard that people are looking for," said Nicolas Cowan, a doctoral student in astronomy and lead author of the paper.

Of course, oceans do not necessarily mean life, especially intelligent life, but such a discovery would help focus the search on more promising planets. It will, however, require a new generation of space telescopes.

And if Shostak is right, we may already know by then.

"If we don't find ET within a generation, there is something very fundamentally wrong with our assumptions," he said in his talk, which was published in Caltech's quarterly, Engineering and Science.

It would make things a lot easier if ET would just give us a shout.

Copyright © 2009 ABC News Internet Ventures

SETI Chief Astronomer: "Humans Predicted to Make Contact with an Extraterrestrial Civilization Within Two Decades"--A Galaxy Classic

"That's 500 billion planets out there, and bear in mind there are 100 billion other galaxies. To think this [the Earth] is the only place where anything interesting is happening, you have got to be really audacious to take that point of view."

Seth Shostak, SETI senior astronomer

Some leading astronomers are quite confident that mankind will make contact with intelligent alien life within two decades. The search for extraterrestrial life will leap forward next year when NASA launches the Kepler space telescope. The instrument will be constantly scanning the same 100,000 stars over its four-year mission with the exciting objective of discovering Earth-sized planets in the habitable zones around suns.

This will allow SETI to home in on where the odds of life are possibly greatest. Currently, SETI’s mission to find life on other planets is like trying to find the proverbial needle in a haystack. But now, whenever Kepler identifies planets most likely to sustain life, the team at SETI will be able to focus in on those solar systems using deep-space listening equipment. This will be a huge upgrade from their present work of randomly scanning the outer reaches of space for some kind of sign or signal. Also, upping the ante, is the recent discovery of Earth-like planets outside our solar system, which has led astrophysicists to conclude that Earth-like planets are likely relatively common in our galaxy.

"Everything has caused us to become more optimistic," said American astrophysicist Dr Frank Drake in a recent BBC documentary. "We really believe that in the next 20 years or so, we are going to learn a great deal more about life beyond Earth and very likely we will have detected that life and perhaps even intelligent life elsewhere in the galaxy."

However, some astrophysicists have warned that we humans may be blinded by our familiarity with carbon and Earthlike conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Earth, one species “sweet spot” is another’s species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based occasion.

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.

Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

So what about water? Isn’t at least water essential to life? Not necessarily. Ammonia, for example, has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based "habitability zone". One example of such a location would be right here in our own solar system on Saturn's largest moon Titan.

Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.

At any rate, the odds of there being some type of life somewhere out there are good. As for intelligent life, well, that will depend on the definition of intelligence. There are a lot of other intelligent species here on Earth besides humans, that we don’t generally regard as such. In spite of many Star Trek episodes to the contrary, the odds of alien life forms having evolved to talk, look and act exactly like super hot humans are slim to none. If life is out there, it will have evolved according to it’s particular niche in the universe and will likely be quite foreign to us in the way it looks, communicates and thinks. We might not even be able to recognize hypothetical life forms as alive in the sense that we understand life. In fact, it would be more “miraculous” if we could effectively communicate with extraterrestrial life than to find that it exists. From that perspective, even if there are other life forms out there, we’d still be alone in the universe. Of course, that doesn’t mean we shouldn't look for the answers.

Posted by Rebecca Sato.

First-Ever Asteroid Tracked From Space to Earth

By Betsy Mason

For the first time, scientists were able to track an asteroid from space to the ground and recover pieces of it. The bits are unlike anything ever found on Earth.

The asteroid was spotted entering Earth's atmosphere over Sudan in October and was believed to have fully disintegrated, but an international team found almost 280 pieces of meteorite in a 11-square-mile section of Sudan's Nubian Desert. The largest was the size of an egg. Lab analysis showed that the rocks belong to a rare class of asteroid that has never been sampled in such a pristine state, so it could fill some gaps in our understanding of the solar system's early history.

"It's the first time we've been able to track something through the air and watch it fly apart and then find pieces of it," microbial ecologist Rocco Mancinelli of SETI, a co-author of a study on the meteorite pieces Wednesday in Nature, told Wired.com.

Finding the meteorites was a long shot, but because the rocks would be so important, meteor astronomer Peter Jenniskens of SETI, lead author of the study, took a bus loaded with 45 students and staff from the University of Khartoum deep into the desert to hunt for them. A 10-hour bus ride and an 18-mile trek through the sand took them to the remote area where scientists thought the rocks, if they existed, would be. The group began sweeping the desert in a line and two hours later the first meteorite was found by a student.

"It was very, very exciting. Everybody was celebrating," Jenniskens said. "You have to remember how important it is to find a piece linked to an asteroid we have seen in space."

Scientists use asteroids to learn about the early solar system because they are among the oldest objects in the universe and can remained relatively unchanged from when they formed, providing a historical snapshot. It is estimated that hundreds of meteorites fall to Earth each year, but only a few end up in the hands of scientists.

Because asteroids are typically surrounded by a shroud of dust as they travel through space, they reflect light differently in flight than they do in the lab, making it difficult to connect meteorites found on Earth with particular types of asteroids. But because the car-sized Sudan asteroid was spotted 20 hours before it hit Earth's atmosphere, scientists were able to determine that it was an unusual type of asteroid that falls between the two most common types.

For the first time, scientists can begin to connect the light signatures of asteroids in space to signatures of meteorites in the lab.

"This is like the first step toward a Rosetta Stone for classifying asteroids," said study co-author, cosmic mineralogist Michael Zolensky, at a press conference at NASA's Johnson Space Center Wednesday.

The team, led by Jenniskens, hopes the intermediate meteorites will reveal details about how planets formed in the early solar system.

"It gives a window on the past," Jenniskens told Wired.com. "You see a little piece of early history coming into focus."

The Sudan meteorites are from a rare class of asteroids known as ureilites, which contain a lot of carbon, much of it in the form of graphite, as well as diamonds produced by shock. The Sudan specimens show evidence of volcanic activity, which means they came from a parent body that was almost big enough to call a planet.

"It's showing us that this asteroid had planet-like activity on it," said astronomer Lucy McFadden of the University of Maryland, who was not involved in the study. "We're lucky that the Earth was in the right place and placed itself in front of this new meteorite."

But that planet shut down, lost its heat source and quit growing, Zolensky said. This gives scientists a glimpse of a specific stage in the evolution of planets.

"What this does is give us first-hand knowledge of what happens when planetesimals form from one that fell apart and failed to become a planet," Mancinelli said. "It really tells you what happens when these rocks bang into each other and some actually stick to each other and form a planetesimal."

There's nowhere else to find this sort of information, he said, because you need the planet forming process to stop before it becomes a full-fledged planet.

"This is highly unusual," Mancinelli said. "It is key to understanding the early solar system."

Space scientist Ted Bunch at Northern Arizona University studies these rare meteorites. "Of the tens of thousands of meteorites that have been found, there's probably only 100 that are ureilites," he said.

Ureilites are interesting in that they have a very primitive composition, Bunch said. And the Sudan ureilite pieces are even more rare because they were picked up so soon after they fell. Meteorites that have been lying around on Earth for a long time can become contaminated.

"To see something which is pristine, the chance of contamination is pretty low," Bunch said. "Whatever you see in the stone is what came from outer space, with no contribution from Earth."

Image 1: The contrail left by the asteroid's passage through the atmosphere.Credit: Muawia Shaddad.
Image 2: Typical meteorite fragment. Credit: Muawia Shaddad.
Image 3: This space-based view of the Nubian Desert shows altitude in kilometers (in white circles) and meteor locations in red. Credit: NASA Ames/SETI/JPL.
Image 4: Students from the University of Khartoum line up to go meteorite hunting in the Nubian desert. Credit: Muawia Shaddad.

Could Aliens Be Sending Us Laser Signals?

Over a decade ago SETI pioneer Jill Tarter and I had a dinner discussion about the protocol procedures for announcing to the world the first detection of a signal broadcast from an extraterrestrial civilization.

I expressed relief that I would never have to worry about publicizing such a discovery from Hubble Space Telescope. “Hold on Ray,” Jill said, “you never know, Hubble might conceivably pick up a signal that other telescopes can’t detect.”

Oh, my worst nightmare! Imagine keeping that information under a news release embargo!

Now, some readers will scratch their heads at this because SETI has been popularized in the 1997 movie Contact where actress Jodie Foster “listens” for radio signals from E.T. with the huge radio telescope array near Socorro, New Mexico.

But another communication strategy that aliens might use instead of radio signals is to send brief and intense bursts of laser light across the galaxy – sort of like a signal lamp between two ships. Some space telescopes would be ideally suited to pluck out such a signal from the sky background.

Why laser beams instead of radio transmitters? A directed beam across interstellar space would be unmistakable from the stellar background and could penetrate thousands of light-years. With each pulse of energy a signal from a big enough laser optics system could appear 1 million times brighter that the transmitting planet’s parent star. The thought is that an alien society would use an agile laser-transmitter to “paint” nearby target sunlike stars with a “searchlight beam.”

An advanced alien civilization would not have to bust its annual GNP to construct a super-laser. Ideally, they would build a telescopic mirror the width of 10 football fields. They’d shine a laser into it that is capable of pumping out a blinding 1 quadrillion watts of energy in brief bursts (just such a laser is already in operation at the University of Texas).

Now, a petawatt is 1,200 times the entire electrical generating capacity of the United States -- but the shots last for less than a trillionth of a second each. The laser could pulse at one blast per second or so.

The pulse sequence might have a mathematical pattern embedded in it. This could yield a complex and lengthy message, or simply repeat a shorter transmission for redundancy (so long as it does not decode into those sappy musical tones from the 1977 film Close Encounters of the Third Kind)

There have been numerous optical SETI (OSETI) searches with ground-based telescopes, going all the way back to the early 1970s. Ironically, the newly launched NASA Kepler space observatory might be capable of stumbling across just such a signal too. It has the light sensitivity, photometric precision, time resolution, and sample size (170,000 stars) to do, serendipitously, an unofficial (and unsanctioned) OSETI experiment from a space platform.

In addition to doing a census of stars with Earthlike worlds, it is not entirely impossible – however remote – that the observatory could stumble upon an artificial laser transmission. In fact SETI researcher Steve Kilston has gone so far as to assert that if Kepler doesn’t get laser-zapped, the result would statistically reduce the estimated number of actively laser-transmitting civilizations in the Milky Way Galaxy to less than one million (and of course it could also be "zero").

A variety of other space telescopes could be similarly adept at coming across an OSETI signal. The European Space Agency’s Gaia observatory (2011 launch) will map the position and velocities of one billion stars in our galaxy. Its onboard multi-color photometer is capable of serendipitous OSETI detections.

A wildly ambitious, spendthrift super-civilization – a million years more technically evolved that us -- might build a moon-sized laser mirror. They would tap a fraction of their star’s energy just to power a godzillion-watt laser capable of transmitting an intergalactic beacon across millions of light-years.

Perhaps a future space telescope might intercept such a signal. The question is, how long will it take the researchers to shake off their amazement and disbelief, and dare tell their colleagues?

Photo Credit: University of Texas, Adam Contos/Ball Aerospace