Why Is SETI Not An Interstellar Switchboard?

Monolith by highdarktemplar on DeviantArt.

"Monolith" by highdarktemplar on DeviantArt.

On reading an article in The Daily Galaxy today, I was interested by what the author had to say. In a nutshell, the article pointed out that it is a big mistake to believe we are the only intelligent life in the Milky Way.

Why is that?

The only reason given was that there are billions of stars, it is therefore foolish to think we are the only example of an advanced species. Unfortunately, there is no evidence to suggest that we aren’t the only intelligent life form in our galaxy. Just because there are hundreds of billions of stars possibly with billions of habitable planets does not constitute evidence that we’re not alone. That’s what science is all about, formulating a theory and then gathering the evidence. Simply saying, “There’s lots of stars, therefore there must be an intelligent species out there,” doesn’t cut it.

Dr Frank Drake toiled with this idea to eventually arrive at the famous Drake Equation, a concept I have never felt at ease with:

At first glance, we could say that the Drake equation really is nonsense (after all, how can any equation predict more than one intelligent civilization in our galaxy, when we only have experience of one: us), and that we are the only kids on the Milky Way block. — from If There’s an Alien Race Living on our Doorstep, Why Can’t We Hear Them?

How can you arrive at the conclusion that we are not the only intelligent life in the galaxy simply because there are a lot of stars?

Familiarity

What can we expect ET to look like?

What can we expect ET to look like?

It is true that the Milky Way contains billions of stars, of which a high percentage probably have exoplanets not dissimilar to Earth orbiting them. There’s every chance that a smaller percentage of those Earth-like terrestrial exoplanets have some kind of basic life form slivering around (or indeed swimming, flying, walking or ‘talking’). Also, there’s the chance that some of these exoplanets have nurtured something that we’d consider to be ‘intelligent.’

Now this is where things start to get a bit tricky.

There are massive international efforts under way to find any kind of extraterrestrial life. We’re toasting soil samples on Mars in the hope of finding the biological signature, and we’re using full-blown antennae scouring the skies for any organized signal from an intelligent alien species. However, whether we are looking for microbial life in the Solar System or something a little more sophisticated beyond, our search for extraterrestrial life is based on only one model: Earth.

It’s all very well saying that we should be looking for other possible forms of life, but if we have no experience of it, how do we know what to look for?

It’s a similar question to, “What is beyond a black hole’s event horizon?” We have no idea, because we cannot experience it, the physics of our Universe simply do not apply beyond an event horizon.

There are a lot of ideas, theories and conjecture but at the end of the day, we have to assume ET will have some trait we are familiar with.

When looking for intelligent extraterrestrials we make the assumption that these civilizations have progressed in a similar way to us, eventually transmitting radio signals (perhaps even laser beacons) to communicate on their home world, between planets with their own kind, or even reaching out into the cosmos, signalling their presence to other life forms capable of receiving interstellar signals.

We’ve been leaking radio signals into space for the last century and we are constantly communicating with our planetary probes. There’s every chance that if there’s an intelligent alien (with a radio receiver) within 100 light years, we may have already been detected. We are also being a bit more proactive these days, using programs such as Messaging Extraterrestrial Intelligence (METI) to make our presence known. (But what should we be saying?)

SETI, METI, SETA… SETT?

The Arecibo radio antenna, used by SETI

The Arecibo radio antenna, used by SETI

Unfortunately, apart from one isolated case, the Search for Extraterrestrial Intelligence (SETI) has drawn up blanks, we don’t think we’ve heard anything in the cosmos that’s originated from an alien.

On this single null result, we could jump to the conclusion that there is no other form of ‘intelligent’ life in our galaxy. Say if the ‘Rare Earth‘ theory is correct, and we are indeed the only form of intelligent life in our galaxy? But there are other explanations. What if ET is signalling via another method? What if there is some interstellar mechanism that is hindering (or even blocking) the transmission of electromagnetic communications? All these questions are valid as there is no scientific evidence to support otherwise. It’s very quiet out there, a fact that is bugging scientists quite a bit, and this problem been dubbed the Fermi Paradox.

The Milky Way is very old, in fact, the oldest star in our galaxy has been burning for 13.2 billion years (compare that with the age of the Universe at 13.74 billion years); you’d logically think that something resembling an intelligent civilization would have popped into existence in that time. If they did, surely we’d have detected them by now, wouldn’t we?

Actually, this spawns yet another debate: Have ancient interstellar alien civilizations come and gone? Was there a frenzy of intelligent life popping up all over the galaxy in the billions of years that our Sun was a proto-star surrounded by a proto-planetary disk? If old alien intelligence has since become extinct, our few thousand years as an evolving civilization is a mere spark in universal time scales. Could it be that we’ll have to wait until we can actually visit interstellar destinations first-hand to do the SETI equivalent of an archaeological dig, looking for alien artefacts? Perhaps SETI should be changed to the Search for Extraterrestrial Artefacts (SETA), where we’d have to look for evidence of alien civilizations past.

Dyson Microcosm by justravelin on DeviantArt

"Dyson Microcosm" by justravelin on DeviantArt

There’s another factor to consider. What if an advanced extraterrestrial civilization simply isn’t transmitting? If this is the case, perhaps we should consider a Search for Extraterrestrial Technology (SETT). In this case we could look for alien megastructures, searching for the stuff of science fiction. These structures could include examples of Dyson Spheres, huge alien-made hollow spheres containing a star; a means to harvest all the stellar energy for a vastly advanced civilization.

These are all options, and we shouldn’t close any possibility, no matter how extreme they may be.

Conclusion

There’s a reason why we haven’t received a signal via SETI, but we have no idea about what it could be. We really could be alone in the Milky Way. But then again, there’s a huge number of reasons why we might not be receiving a message from an intelligent species.

SETI may not be an interstellar switchboard, but the reasons for this are far from obvious. The theory that we are alone is just as valid as the theory that we are actually a part of a vast interstellar ecosystem. Until we have scientific evidence, we can’t say either way.

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Cassini Detects Salt: Enceladus Probably Has a Liquid Ocean

The small icy Saturn moon might have liquid sub-surface oceans after all (NASA)

In October 2008, Cassini flew very close to the surface of Saturn’s icy moon Enceladus. From a distance of only 50 km from the moon, the spacecraft was able to collect samples of a plume of ice. In an earlier “skeet shot”, Cassini captured detailed images of the cracked surface, revealing the source of geysers blasting the water into space. At the time, scientist were able to detect that it was in fact water ice, but little else would be known until the molecular weight of chemicals in the plume could be measured and analysed.

At the European Geophysical Union meeting in Vienna this week, new results from the October Enceladus flyby were presented. Frank Postberg and colleagues from the Max Planck Institute for Nuclear Physics have discovered traces of sodium salts and sodium bicarbonate in the plume for the first time.

It would appear that these chemicals originated in the rocky core of the moon and were leached from the core via liquid water. The water was then transported to the surface where it was ejected, under pressure, into space. Although scientists are aware that the chemical composition in the plume may have originated from an ancient, now frozen, sub-surface ocean, the freezing process would have isolated the salt far from the surface, preventing it from being released.

It is easier to imagine that the salts are present in a liquid ocean below the surface,” said Julie Castillo of NASA’s Jet Propulsion Laboratory in Pasadena, California. “That’s why this detection, if confirmed, is very important.”

This is the best evidence yet that Enceladus does have a liquid ocean, bound to cause a stir amongst planetary scientists and re-ignite excitement for the search for life living in a salty sub-surface ocean.

Source: New Scientist

Scientists Create Synthetic Life… Now What?

You talk about synthetic life like it's a bad thing - Tricia Helfer in BSG

You talk about synthetic life like it's a bad thing - Tricia Helfer in BSG

Say if you’re in space, searching for life, what do you look for? That’s simple. You look for something that resembles life on Earth; whether that be single-celled amoeba or a Star Trek-style humanoid with a lumpy head and webbed feet.

That’s life we know and understand (with some sci-fi comedy thrown in). What if there are some other unimaginable creatures that may not fit into our understanding of How Things Work™? This is a very real problem NASA has been faced with ever since the agency started sending probes to Mars and spacecraft beyond the Solar System itself. Deep space missions (like the Voyager and Pioneer probes) have intelligent life forms in mind (i.e. ones that can read, hear and interpret the Leonardo da Vinci Vitruvian Man; so it would be nice if ET also has an appreciation for fine art), but our intrepid Mars rovers and landers that have been pestering the Red Planet since the 1960s are looking for the basic building blocks of life, plus evidence of past or present life. So far, there’s been a lot of rocks turned over, yet no sign of extraterrestrial life.

Therefore, scientists at a very early stage defined “life” as a self-sustaining chemical system capable of Darwinian evolution so we can focus on finding life we know and understand. To boost this understanding a little further, wouldn’t it be great if we could create our own evolving soup of chemicals?

Now, it seems, this has become a reality. Scientists in a Florida lab have created a beaker filled with synthetic life
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Astroengine Interview with Dr Richard Greenberg: “Unmasking Europa”

A future mission to the Jovian moon Europa could incorporate a life-searching robotic submersible under the icy crust (NASA)

A future mission to the Jovian moon Europa could incorporate a life-searching robotic submersible under the icy crust (NASA)

On Wednesday (Feb. 18th), NASA and ESA decided to “prioritize” a mission to Jupiter. Set to be launched in 2020 (for a 2026 arrival in the Jovian system), NASA will work on a spacecraft called the Jupiter-Europa mission and ESA will work on the Jupiter-Ganymede mission. Both probes will be launched at the same time to carry out this unprecedented planetary mission. However, this doesn’t mean a mission to Saturn will be off the cards; NASA hinted that a return trip to the ringed gas giant will also be planned in tandem (following in the footsteps of the Cassini Equinox Mission). But Jupiter comes first.

In an enlightening interview earlier today, Dr Richard Greenberg, an eminent Europa scientist, discussed this recent NASA/ESA announcement with Astroengine Live and his excitement that there will be a return mission to the Jovian system. He is an expert in celestial mechanics and worked on several NASA projects at the University of Arizona’s Lunar and Planetary Laboratory. Dr Greenberg has also published a book called “Unmasking Europa” (of which I am very excited to receive a copy soon), detailing the science under the icy crust of the moon, where there is a tantalizing possibility life may thrive in tidally-heated sub-surface oceans.

But that’s not the best part. Dr Greenberg provides an exciting narrative about what form this Europa (European?) life may take… It’s not just microbial extraterrestrials that could survive in these environments

Be sure to listen in to my radio show, Astroengine Live on Wednesday, February 25th to hear the full recording of my conversation with Dr. Richard Greenberg.

Liquid Water on Mars?

Water droplets appear to be growing on Phoenix's leg shortly after landing on Mars (NASA)

Water droplets appear to be growing on Phoenix’s leg shortly after landing on Mars (NASA)

NASA scientists are currently trying to understand a set of images taken by the Phoenix Mars Lander shortly after it landed on the Red Planet in May 2008. The images in question show one of the robot’s legs covered in what appears to be droplets of liquid water. The droplets remain on the lander for some time, appearing to get larger and changing shape.

By now, we know that liquid water (apparently) hasn’t existed on the Martian surface for hundreds of millions of years; the atmosphere is currently too thin and too cold to support liquid water. However, the confirmed presence of perchlorate in the regolith may provide an important clue as to what might be going on…
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The MSL is Too Expensive? Who Cares! We’re Searching For Life!

$2.2 billion eggs. One basket. The MSL "Skycrane" lowers the 850kg rover to the Martian surface (NASA)

$2.2 billion eggs. One basket. The MSL Skycrane lowers the 850kg rover to the Martian surface (NASA)

Don’t get me wrong, I am incredibly excited about any planetary mission, no matter how much it costs. However, there is something about the Mars Science Laboratory (MSL) that makes me uneasy. The project may be delayed (the MSL is scheduled for a 2011 launch) and it may be costing more than NASA projected, but it’s not these factors I’m worried about.

The MSL is built on a “bigger and better” mentality; it dwarfs both of the Mars Exploration Rovers Spirit and Opportunity, plus it is packing a rather impressive suite of 10 complex scientific instruments to carry out an unprecedented campaign in the Martian dirt. Oh, and did I mention it will be powered by radioisotope thermoelectric generators (RTGs), a complete departure from the tried and tested solar panelled rovers? Oh hold on, as the MSL weighs nearly a tonne, a brand new method of landing the thing is required (simply parachuting, air bag bouncing or rocket thruster powered landings are now passé). The “Skycrane” that looks like one of those hoverboards from Back to the Future II has been invented to gently lower the MSL (pictured above).

Still, I’m not too concerned, NASA has proven itself countless times at overcoming technological challenges. That’s why NASA is there, to research and develop new technologies and science. But what if the MSL has gone too far? What if the technology is too untried and untested? Unfortunately, it looks like the recent turn of events have taken even the MSL program manager by surprise
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Twitter Journalism: Methane on Mars, The Signature of Life?

The distribution of atmospheric methane originating from three principal regions on the Martian surface (NASA)

The distribution of atmospheric methane originating from three principal regions on the Martian surface (NASA)

Today, NASA held a press conference detailing some significant discoveries from observations made of the Martian atmosphere. Using NASA’s Infrared Telescope Facility and Keck Telescope, scientists from the University of Hawaii and NASA were able to deduce the spectroscopic fingerprint of methane. Although scientists have known for a long time that methane exists in the Martian atmosphere, the big news is that there is lots of it, it appears to be constantly replenished and it is a huge indicator of biological processes under the surface.

Fortunately, I was able to watch the NASA TV broadcast of the press conference at 11am (PST), so I thought I’d try, for the first time, to do some live microblogging of the announcements using Twitter. So, rather than going into vast detail about today’s methane news (as the web has exploded with articles on the subject anyway), I thought I’d publish my Twitter feed during the conference
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