Category Archives: NASA

astrobiology, exoplanets, exploration, extrasolar planets, GJ 1214b, life, mono lake, NASA

Arsenic-Eating Life and New Planets

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Scientists Study Places Where Life Thrives…

and where it May Someday Exist

Judging by the uproar over the past few days in the blog-o-sphere and comment-o-sphere, you’d think that NASA was announcing that life had been discovered on Mars or Titan or any number of other unlikely places.  What I’ve seen in idle speculation and comments on blogs, FaceBook, and even on some news sites,  leads me to wonder if there’s any intelligent life left on the Web. I mean, come on.  There’s been some pretty irresponsible commentary by all kinds of people (including journalists, bloggers, and some scientists) and it’s really taking away from the wonderfulness of the actual discoveries.  Well, let’s take a look at the REAL stories and see what all the fuss is about.

Arsenic-processing bacteria like those growing in Mono Lake, California. Courtesy NASA.

The first, being talked about today, is the finding that some bacteria that live in Mono Lake in California appear to eat and apparently thrive on arsenic — a chemical that is usually toxic to life.  This finding is based on laboratory studies of these bacteria. In such a setting, not only can these buggers eat the stuff, but they appear to have evolved enough to be able to chemically alter it and incorporate it into their DNA. The lead researcher, Dr. Felisa Wolfe-Simon at the U.S. Geological Survey, put it pretty well: “”We know that some microbes can breathe arsenic, but what we’ve found is a microbe doing something new — building parts of itself out of arsenic,” she said. “If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?”

Bugs eating arsenic?  That result is going to have a huge impact on other areas of research into life and its processes, including the study of Earth’s evolution, organic chemistry, biogeochemical cycles, disease mitigation and Earth system research.  To put it simply, this has implications for understanding the chemical environments that life can exist and thrive in.  Essentially, this NASA-funded research is changing our very basic knowledge about what kinds of life forms we have on this planet, and where they can exist and thrive.

Now, this is a far cry from breathless claims that NASA was going to announce life on Mars and all the other shouting that we’ve been seeing on the Web and in the press the past couple of days. Those are the usual claims, and I find them wearisome when they come without any proof or understanding of the actual science being reported.

On the other hand, this report is REAL science being shared by real scientists who have been out the field doing what science does best: examining, studying, and understanding what’s right in front of us. It’s exciting. It’s different. And, it’s going to spur other scientists to study the results and extend them into other areas.  But it’s not little green life forms holding up their middle fingers and saying, “Take me to your arsenic.” Quite the opposite: the little life forms seem to have found their arsenic and said, “We’re happy here, thank you very much.”

You can also read more about this fascinating biological discovery at Science’s web site, the journal that is publishing the story of the arsenic-loving critters.

Artist's conception of the super-Earth planet GJ 1214b. Courtesy ESO.

The second discovery this week that has implications for life is the revelation by astronomers using the Very Large Telescope in Chile of a super-Earth exoplanet (i.e. a semi-Earthlike planet bigger than Earth) that has what appears to be a water-rich atmosphere.   This water could be in the form of steam, or wet clouds or hazes.  GJ 1214b has a radius of about 2.6 times that of the Earth and is about 6.5 times as massive. Its host star is a small faint star about 40 light-years from Earth in the constellation of Ophiuchus. You can read more details here.

Of course, as soon as news of this discovery came out, I began to see speculation about life being discovered on that planet.  Not just in news sites, but all around the web-o-sphere and by commentators who should have known better.  I hate to be a wet blanket (so to speak), but the presence of water does NOT equal the presence of life. It DOES mean, however, that the environment on that planet could be conducive to the formation of life that depends on water.  And, that’s pretty darned cool.  Still, no actual discovery of life has happened there… yet.

I think that this tells us, more than ever, that the conditions for life do exist “out there” and that the formation of planets where life could form and exist is not limited to our own solar system.  It’s not surprising to find these planets — eventually we were bound to. Coupled with the astrobiology discovery announced today, it tells ME that this universe is complex, fascinating, and always ready to hand us a surprise or two!

atmosphere, atmospheric science, chemistry, NASA

The Hole at the South Pole

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The Ozone Hole

Earth's ozone hole, from data provided by NASA's Goddard Space Flight center and the Ozone Hole Watch. The blue area is the 'ozone hole', where the density of the ozone layer is at its thinnest this time of year.

One of the best things that NASA does (along with other space agencies) is give us a look at our own planet — as a planet.  That is, the scientists who study our world do so in the same way they would study any other planet. They chart changes on the surface, map atmospheric activity, and chart all those changes over time.  For the past decades, scientists have charted something called the ozone hole, which forms over the south pole of our planet each year.  This image shows what the ozone looks like as of September 13, 2010, courtesy of the OzoneWatch website.

Satellite instruments monitor the ozone layer, and scientists use the data to create the images that indicate the amount of ozone in the upper atmosphere. The blue and purple colors are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone.  The depth and size of this Antarctic ozone hole are affected by the temperature of the stratosphere (the upper part of Earth’s atmosphere) and the amount of sunlight that bathes the south polar region.

So, why is ozone such an important thing to monitor? This is a useful gas for the protection of life on this planet.  In the upper atmosphere, ozone acts to absorb ultraviolet-B emissions.  Such emissions, which come primarily from the Sun, can harm living systems. It’s safe to say that, without the ozone layer in our upper atmosphere, life on Earth would be severely harmed.  In fact, without the ozone layer, it’s possible that life wouldn’t have formed on this planet.  So, losing a chunk of our ozone layer each year is a big deal.  Scientists want  understand why this happens.

Now the good news is that the ozone layer is not thinning anymore — after more than half a century of actively thinning.  This is due to a ban on harmful chemicals that have damaged the ozone  layer.

We know that ozone is destroyed by chlorine- and bromine-containing chemical compounds.  We know that some aircraft emissions hurt the ozone layer.  We know a lot of different reasons why our ozone layer is under attack, not just from the Sun, but from below by the sentient life forms that inhabit the planet.

Sure, there are naturally occurring attacks on the ozone, but the largest attack comes from human activity. We use huge amounts of chemical compounds in industrial and home-based products. You may have heard of what’s referred to as chlorofluorocarbons. They escape to the atmosphere from refrigeration and propellants.  They persist for years in the lower part of the atmosphere, and eventually some migrate to the upper atmosphere. It’s a long-term process because the destruction of ozone doesn’t happen the minute CFCs get into the atmosphere.  But, it does eventually happen. So, even though we HAVE reduced our use of these compounds — the damage from the reservoir of ozone-destroying atoms and molecules has continued.  The damage that now shows up in the ozone hole probably comes from materials released well into the last century. With luck, and the continued ban on these chemicals, the ozone should get back to its 1980 levels by mid-21st century.

I know that there are still people who deny such problems existed — generally they are people who don’t want to believe that humans can have a deleterious effect on our planet’s ecosystems. The problems won’t go away because some people bury their heads in the sand. Oh, sure, their faces won’t get sunburned by the UV-B, but their hineys will.

So, what’s the effect of the loss ozone? Ask the people who live under that hole and who are at higher risk for cancer and other conditions that are caused or exacerbated by exposure to ultraviolet-B.  I was in South America a few years ago, at the very tip of the continent. The people who live there know first-hand what it’s like to live under a thinning ozone layer.  Sunblock is a constant friend.  Children are warned NOT to go out with out adequate clothing and sunblock.  If you want to know what life would be like on this planet with a thinner (or nearly nonexistent) ozone layer, talk to the children of Patagonia.

And, thanks to NASA and other agencies who continually monitor our planet from space (another fine example of how space exploration benefits us here at home), we might be able to learn enough to avoid dissipating our ozone layer more than it already is.