April 5, 2013
Building Blocks For Life May Be Found On Jupiter’s Moon Europa
Brett Smith for redOrbit.com - Your Universe Online
The building blocks of life are strewn across the galaxy on or beneath many planetary surfaces and new evidence from NASA suggests that the necessary cocktail for life could be sitting right on one of Jupiter´s moons.
According to the study, Jupiter´s moon Europa has enough hydrogen peroxide on its surface to potentially support life if it were to somehow mix with the ocean trapped beneath the moon´s icy surface. The scientists said that the peroxide is created by the interaction between Europa's surface ice and the radiation generated by Jupiter's strong magnetic field.
"Life as we know it needs liquid water, elements like carbon, nitrogen, phosphorus and sulfur, and it needs some form of chemical or light energy to get the business of life done," explained NASA´s Kevin Hand, the lead author of the study, which is published in Astrophysical Journal Letters. "Europa has the liquid water and elements, and we think that compounds like peroxide might be an important part of the energy requirement. The availability of oxidants like peroxide on Earth was a critical part of the rise of complex, multicellular life."
The study´s findings are based on imagery collected in the near-infrared range of light from Europa by the Keck II Telescope in Hawaii during September 2011. The researchers found that the greatest concentration of peroxide, 0.12 percent relative to water, is located on the side of Europa that always leads in its orbit around the gas giant. This concentration is about 20 times weaker than the hydrogen peroxide that is used as a disinfectant. On the opposite or trailing side of Europa, the concentration of peroxide drops off to nearly zero.
While the discovery is significant, it´s not the first time that scientists have discovered peroxide on Europa. When NASA's Galileo mission explored the Jupiter system from 1995 to 2003, it was the first to notice the presence of peroxide, but Galileo observations were only on a limited scale.
The new observations show that hydrogen peroxide is spread across much of Europa, with the highest concentrations located where Europa's ice is almost pure water with very slight sulfur contamination.
In their report, the authors noted that high concentrations of hydrogen peroxide could be located at the moon´s poles, which are not readily visible from here on Earth.
"The Galileo measurements gave us tantalizing hints of what might be happening all over the surface of Europa, and we've now been able to quantify that with our Keck telescope observations," said co-author Mike Brown, of Caltech in Pasadena. "What we still don't know is how the surface and the ocean mix, which would provide a mechanism for any life to use the peroxide."
Because hydrogen peroxide releases oxygen when mixed with water, the scientists added that life as we know it could exist on Europa.
"At Europa, abundant compounds like peroxide could help to satisfy the chemical energy requirement needed for life within the ocean, if the peroxide is mixed into the ocean," said Hand.