When ancient meteorites rained down on earth they brought more than fire and rocks from the sky. They brought the raw genetic material for life. That, at least, is the conclusion of scientific researchers from Europe and the USA.

Freshly published in the journal Earth and Planetary Science Letters, the new study is based on a careful study of the Murchison meteorite which crashed in Australia in 1969. In its materials scientists found the molecules uracil and xanthine which are precursors to the molecules that make up DNA and RNA. After ruling out that they could have come from earth, the study says they came from space, and that means, it says, that life on earth is extraterres­trial in origin.

Conventional science holds that about four billion years ago meteors like the Murchison rained down on earth just when primitive life was getting started. Lead author Dr Zita Martins, of the Department of Earth Science and En­gineering at Imperial College London, says that the research may provide another piece of evidence explaining the ev­olution of early life. “We believe early life,” she says, “may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations.”

The new research buttresses the argument of those who believe in panspermia, the notion that seeds of life exist already all over the universe, and that life on earth originated through these seeds, and that they may deliver or have delivered life to other equally hospitable planets.

So, if life on earth started somewhere else, just how did it get started there? Whether here or there, science still has a lot of explaining to do.

Water Ice Is on Mars

While the matter of whether there is, or ever has been, life on Mars is still—insofar as NASA is concerned—unsettled, at least one question has now been answered definitively. There actually is frozen water on Mars.

As millions on earth watched over television and the Internet, the Mars Phoenix Lander settled softly on the Mar­tian surface, near the North pole on May 25 and despite considerable suspense, everything went smoothly. This was the first time in 30 years that a rocket-assisted soft landing had succeeded. The mission: to determine if there has ever been liquid water on Mars. The presence of such water is believed to be essential to life; after all, it is on warth. First, though, it was necessary to establish that the Lander was actually positioned over ice.

Photos beamed back to earth showed some kind of white substance just beneath the dirt scraped away by the Lander’s scoop. But at first, it was impossible to say whether they were looking at ice or some kind of salt. Over the next few days though, as chunks of the white stuff slowly disappeared, NASA scientists became convinced that it was indeed ice which could melt and not something else.

The next step is to analyze the ice and the water obtained by melting, which will, hopefully, answer many more burning questions about the status of life on Mars, both then and now.

To be continued.

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