By
Ayse Guner
Arizona Daily Wildcat
Seeking an answer to life's origin extends beyond laboratory work.
The only way to understand how life started more than 4 billion years ago is to search outer space, where the mystery of living organisms could possibly be kept frozen to this date, said Jonathan Lunine, a UA lunar and planetary laboratory professor.
Last night Lunine gave his first public talk, about seeking life beyond Earth, to about 240 people, marking the largest turnout for a Steward Observatory lecture audience in the last two years.
Scientists in the 1930s discovered methane and nitrogen elements on Titan, a moon of Saturn, showing a similarity to the organic molecules of Earth, Lunine said. However, because of smog on Titan's surface, scientists cannot detect what is out there until at least 2004, at the conclusion of the Cassini-Huygens mission.
Also, on Europa, a moon of Jupiter, surface features and a magnetic field suggest an ocean beneath, but the environment could possibly kill astronauts, Lunine said.
These satellites, though, could provide what cannot be found on Earth - the transition of chemistry from non-living to living organisms, he said.
The chemistry of non-living organisms is impossible to completely recreate on Earth, Lunine said.
"Making the building block (of a protein) in a lab is easy, but getting the chemistry cannot be done on the Earth," he said.
That is why Lunine has been seeking life in stars, in other planets and moons which the human eye - and sometimes telescopes - cannot detect.
Lunine's research focuses on Earth-like life in other solar systems. In order to understand how such life could be found elsewhere, scientists need to analyze and understand Jupiter's effect on Earth, because it is the primary reason for water on Earth, he said.
This theory was in part discovered by him, along with an international team of six scientists. Lunine published some of his separate findings in the current issue of the Proceedings of the National Academy of Sciences journal.
The solar system formed about 4.5 billion years ago, and in 1 percent of that time, Jupiter tossed asteroids toward the sun, which eventually hit Earth and formed the origins of oceans, Lunine said.
These objects were scattered particles between the Earth and Jupiter, and about 10 percent of their composition was water. Contrary to earlier findings, this study suggests that meteorites were not the only source of water, but these Mars-size particles created most of Earth's water, Lunine said.
Because there are at least 50 other sun-like stars in the solar system, there could be more planets similar to Jupiter - thus meaning there could be water, and life, on those planets' moons, Lunine said.
"There could be Earth on every star, but we don't know that because of the limits on technology," he said.
