Snowing Microbes

Of all the places in our solar system (besides Earth) that are most likely to harbor life, none is better than Enceladus, Sat­urn’s sixth largest moon. Although extremely cold, it has been recording spouting geyser-like plumes of liquid water high into the air. Enceladus is one of only a few other places in our solar system with recorded geologic activity.

Although it is so very cold on Enceladus, that does not have researchers worried, because we have life here in our arctic oceans on Earth.

The lucky thing about the water being sprayed into the air also means that the probes that have been sent to Enceladus do not even need to land! All they have to do is fly through the spray to gather their samples and analyze the liquid. With the envi­ronment being so cold, however, all of the spray is probably being frozen into snow in the atmosphere. 
There are also concerns that perhaps the oceans are far too acidic to support life, but again, it may be possible for mi­crobes to survive in such conditions.

Microbes, are, in fact, what the researchers are looking for; millions of microscopic bacteria and other organisms that live just about everywhere here on Earth. As the water is likely being spurted from the oceans beneath the frozen surface of the planet, any life held within them would be blown up into the atmosphere in the geysers.

Read more from SPACE.com.

Life on Europa: a soda ocean? 03.02.12

Of all of the other places in our solar system, one of the most promising locations for extraterrestrial life has been Jupiter’s icy moon Europa. Completely covered with ice on the surface, researchers believe Europa harbors an ocean of liquid water at least 100 miles deep, which leads down to a rocky interior and a solid core of some type, most likely metal. Surface studies on the moon have yet to be conducted, however, so the re­searchers have no idea how thick the icy crust on the outside of the planet may be.

Credit: NASA.

While the possibility of an ocean of liquid water is more than enough to be excited about, some researchers are beginning to doubt whether or not life as we know it would be able to thrive on the chilling planet. What research has been done on the planet is beginning to lead the scientists to believe that whatever water is there would be highly contaminated by extremely acidic chemicals. There is some speculation that it is possible the acidity could be balanced out by more basal minerals at the ocean floor, but again, it is all speculation.

There are a few places on Earth where some microbes and other life forms thrive in highly acidic environments, but those areas are few and far between. So, the likelihood of life sur­viving on an entire planet like that? Very slim.

Without the bases and minerals at the ocean floor to balance out the pH, though, the researchers say the ocean would have moderately corrosive characteristics, “about the same as your average soft drink,” except it would be more along the lines of hydrogen peroxide than a cola. Swim time, anyone?

Information credit: SPACE.com.

Scientists re-thinking theories for life on Mars, 11.04.11

New interpretations of data from NASA and European orbiters are beginning to come together, suggesting that the possibility for life on Mars is not so strong on the surface, but much more promising for the subsurface directly underground.

This interpretation comes after researchers have discovered clay and certain types of minerals in the Martian subsurface. Clay can only be formed through the interaction of liquid water with rock, so finding clay under the surface suggests a much more consistent liquid presence than it does for the surface, which usually only has frozen ice in its craters and at its poles.

Image credit: Geology.com.

One of the minerals that they have discovered that supports their new theories is a rather icky-colored stone called prehnite. Prehnite can only form in areas where the temperature is over 400 degrees Fahrenheit, so the presence of prehnite and the abundant clay in the subsurface suggests the likelihood for strong hydrothermal (hot water) activity beneath the Martian surface.

That being the case, it is not so strange to think about the likelihood of finding life on Mars. Based on earth’s own geothermal and hydrothermal activity, scientists know it is possible for various kinds of life (usually bacteria and all manner of simple microbes) to live in their own environments, underground, away from the light of the sun.

So, is it time to chuck the rovers and reach for a shovel instead? Not necessarily. More research still needs to be done. There is also more than enough evidence left on the surface of Mars for astronomers to know there was liquid water there at times, and there is still plenty of ice left in some places, so the possibility for life is still there. The idea of finding bacteria on a planet puts the phrase “finding a needle in a haystack” to shame, though. Knowing where to look that is the hard part.

Credit: NASA.

Astrobiologists find alternate chemistry for life...on Earth, 12.02.10

Astrobiologists participating in a NASA funded study at Mono Lake in California have discovered that a strain of bacteria is capable of not only thriving on, but actually altering its genetic makeup to include arsenic. Arsenic is an element that is extremely poisonous to most forms of life on Earth, and chemically behaves in a similar manner to phosphorous, a crucial element to all cells’ “energy-carrying molecule,” and also in creating cell membranes. Arsenic, on the other hand, tends to disrupt metabolic pathways.


“The definition of life has just expanded,” said NASA’s associate administrator for the Science Mission Directorate, Ed Weiler. According to Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence in California, scientists were previously aware of some microbes that could breathe arsenic. Substituting arsenic into its genetic makeup, however, is something completely new and changes everything scientists thought they knew about DNA.


The star of the show is strain GFAJ-1, from the common family of bacteria Gammaproteobacteria. The bacteria was collected from mud samples in the lake and cultivated in laboratory tests. First the bacteria were fed using a mixture of elements that was low on phosphorous and high in arsenic. The mixture was changed to completely leave out the phosphorous and substitute even higher levels of arsenic, and the scientists discovered the bacteria actually began incorporating the arsenic into its DNA in place of the phosphorous. NASA said the results of the study were published in this week’s edition of Science Express.


The image on the left is of the GFAJ-1 grown first in the phosphorous mixture. The second image is of the bacteria once arsenic had been completely substituted into the slurry. Thronateeska Museum Guide and staff astronomer Jim Friese says “this expansion of the definition of life goes hand in hand with all the different and strange worlds we are finding out there [in space].” Scientists are now realizing that different chemistry really does not automatically mean there is no life there.

Image credit: NASA.

Image credit: NASA.

Credit: NASA.