Category: Astrobiology

Princeton researchers have discovered a colony of bacteria that lives more than 3 km (2 miles) underground. This bacteria lives completely cut off from the biosphere on the surface of the Earth, and derives its energy from the radioactive decay of rocks underground. By finding life in these extreme conditions, scientists are expanding their understanding of what kinds of habits can support life.
Continue reading “Bacteria Found Deep Underground”

Rhizocarpon geographicum, species of lichen. Image credit: ESA. Click to enlarge.
One of the main focuses in the search for living organisms on other planets and the possibilities for transfer of life between planets currently centres on bacteria, due to the organisms simplicity and the possibility of it surviving an interplanetary journey exposed to the harsh space environment.

This focus may develop to encompass more advanced organisms following the results of an ESA experiment on the recent Foton-M2 mission where it was discovered that lichens are very adept at surviving in open space.

Lichens are not actually single organisms but an association of millions of algal cells, which cooperate in the process of photosynthesis and are held in a fungal mesh. The algal cells and the fungus have a symbiotic relationship, with the algal cells providing the fungus with food and the fungus providing the alga with a suitable living environment for growth. Lichens are well known extremophiles, being able to survive the harshest environments on Earth. The most striking element of the finding is the complexity of this organism: it is multicellular, it is macroscopic and it is a eukaryote, meaning that on the evolutionary scale it is a much more modern organism than bacteria. In fact lichens can be considered as very simple ecosystems.

The experiment which took place during the Foton mission was called ‘Lichens’ and was one of the exobiology experiments that was located in the ESA Biopan facility. This exposure facility was located on the outer shell of the Foton return module and, once at the correct orbital altitude, opened to exposure the samples inside to open space, i.e. exposed to vacuum, wide fluctuations of temperature, the complete spectrum of solar UV light and bombarded with cosmic radiation. During the Foton-M2 mission, which was launched into low-Earth orbit on 31 May 2005, the lichens, which came from two different species (Rhizocarpon geographicum and Xanthoria elegans) were exposed for a total 14.6 days before being returned to Earth. At the conclusion of the mission the lid of Biopan was closed to protect the lichens from the conditions of reentry. The Biopan was thereafter transported back to ESA ‘s research facility, ESTEC, in Noordwijk, the Netherlands to be opened.

The results of the experiment were presented by one of the experiment team members, Dr. Rosa de la Torre from the Spanish Aerospace Research Establishment (INTA) in Madrid, at a post-flight review in October at ESTEC. Initial conclusions of the experiment, which is under the scientific leadership of Prof. Leopoldo Sancho from the Complutense University of Madrid, indicate that lichens have the capacity to resist full exposure to the harsh space conditions, especially high levels of UV radiation. Analysis post flight showed a full rate of survival and an unchanged ability for photosynthesis.

This experiment opens up many possibilities for future research into the possibility of transfer of life between planets. Follow up experiments could focus on questions such as to what extent lichen, if transported by a meteorite, can survive the reentry conditions into Earth’s atmosphere, i.e. what degree of shielding would be needed for lichen samples to survive? The outcome of this Biopan experiment also suggests that lichens might survive at the surface of Mars. Follow-up experiments on ground and in space are bound to provide further answers to these intriguing astrobiological questions.

Original Source: ESO News Release

Artist illustration of the Terrestrial Planet Finder. Image credit: NASA/JPL. Click to enlarge.
Find life!

If it were up to me; if I were running NASA, or the ESA, or the plucky Canadian Space Agency, I’d narrow my focus like a laser beam to answer this fundamental question: are we alone in the Universe?

Find life on Mars
At the time that I’m writing this rant, there are two robotic rovers crawling around the surface of Mars searching for evidence that water once existed on Mars. The reasoning is that if Mars was wet for a long period of time, it would have given life an opportunity to get a foothold.

Well, the rovers have done it. Both Spirit and Opportunity have turned up evidence that Mars was warm and wet, probably for millions of years. And although there were supposed last only three months, they’re still going strong after 18 months! Their solar panels are being regularly cleaned by gusts of wind, and it’s not unreasonable to expect many more months of service.

But there’s a problem. The rovers are colour blind. They can analyze rocks, and search for past evidence of water, but they’re unable to see evidence of life. No problem, new equipment is being developed back here on Earth that would give future rovers the ability to analyze soil for the telltale traces of life. Other detectors will be able to sniff the air for a whiff of methane gas; another possible byproduct of life.

Those rovers are so successful, engineers should put future developments on hold and just start mass producing them. Build dozens and equip them with the latest and greatest instruments and turn them loose on the surface of Mars. By mass producing the same rover chassis, engineers should be able to bring the costs down significantly. Keep improving the design, but why reinvent the wheel?

If we could have 20+ rovers on the surface of Mars, sampling soil, sniffing air, and testing ice, from equator to pole, it would substantially improve our chances of finding life. It’s no guarantee, of course, but it would sure give us our best shot to find it. And if you do find life, you could send a second generation of rovers to analyze the life in great detail and learn whether we share a distant ancestor; some adventurous microbe that jumped planets.

The implications of finding life on Mars are staggering; it could mean that life is as pervasive in the Solar System as it is here on Earth. But it might also mean that all life in the Solar System is related, as there’s growing evidence that life can travel back and forth between planets on meteorites.

So, even if we find life on Mars, I think the discovery would be bittersweet. Maybe our Solar System is filled with life, but could the rest of the Universe be lifeless?

Find Life in Other Star Systems
I think it’s fair to say that the Hubble Space Telescope is one of the most productive and important science instruments ever created. It has fundamentally changed our view of the Universe we live in. It helped find extrasolar planets and discovered the mysterious dark energy which is accelerating the Universe.

But to find life on other worlds, we need more specialized tools. One of these is the Terrestrial Planet Finder, which is currently scheduled for launch in 2012-2015. If everything goes as planned, this amazingly sensitive space telescope will be finding Earth-sized planets orbiting other stars within a decade. Furthermore, it’ll be so powerful, it can analyze the atmosphere of these planets and see if any of them have large quantities of oxygen.

That’s critical. We have oxygen in our atmosphere because hardworking microbes and plants have been producing it for millions of years. Oxygen is so reactive, it really can’t exist in the atmosphere unless there’s a constant source refreshing it. So, if you find oxygen, you’ve found life.

So imagine, in just a decade from now, scientists will be able start analyzing nearby stars and turning up planets with biospheres. You could look up in the sky and start pointing out stars to your friends. “Life… life… life.”

Now wouldn’t that be a groundbreaking discovery? Are we alone in the Universe? We might be able to say, “nope, there’s life everywhere.”

I think the Terrestrial Planet Finder is going to be such a fundamental instrument, it’ll become a bottleneck. Scientists will be lined up for 20 years waiting for a shot to use it. We should build more than one. Once again, we should consider “mass producing” them and analyze many planets at once. Bring down the costs, and give scientists a chance to build up a census of the life surrounding us.

But are we talking about intelligent life or slime mold? We won’t really know. (Well, astronomers might figure out how to detect chloroflourocarbons and guess that a planet is in the golden age of air conditioning.)

Until we actually find intelligent life out there, we’re still going to feel a little lonely.

Find Intelligent Life in the Universe
If you’ve seen Contact, you’ll remember Jodie Foster’s character was searching the heavens with a powerful radio telescope, hoping to hear communications from a distant civilization.

This technology exists. For more than 20 years, SETI (Search for Extraterrestrial Intelligence) researchers have been listening to various stars and precise frequencies, hoping to hear a message from afar. The problem is that our Milky Way is an enormous place, with quadrillions of stars. And the number of frequencies are so vast, that it’ll take a long time to search the sky comprehensively.

Technology is improving, and SETI researchers are now able to scan many stars quickly in many frequencies, but it’s still a fraction of the total sky. The computing power to analyze these data is tremendous, but millions of people around the world have installed SETI@home on their personal computers to lend a hand.

Unlike the Mars rovers and various planet finding missions, SETI gets very little public funding. And this is a tragedy. In a single stroke, SETI could discover intelligent life in the Universe, and maybe even help us communicate back. I’d like to watch educational television broadcast by a civilization millions of years more advanced than us.

We need to develop a mega project to scan the entire sky at all the likely frequencies, and even search optical wavelengths too – in case aliens are using lasers to communicate with us.

Find Life: on Mars, on other planets, across the Milky Way.
We live in an amazing time in human history. We’ve wondered about our place in the Universe for thousands of years, and now we’re within arms’ reach of finding the answers. Who knows? Maybe in just a few decades we could have some definitive answers.

And if we don’t find life on Mars, orbiting other stars, or communicating to us across the vast distances of the Milky Way, it’ll tell us something else.

Something just as important.

Maybe life here on Earth is more precious than we thought. We should take better care of the planet we live on, and the creatures we share it with – it might be unique in the Universe.

Let’s start cranking out those rovers, planet finding telescopes and radio dishes and get an answer. (And if I had to choose, I’d probably advocate putting other stuff on hold while we looked).

Written by Fraser Cain