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Did Mars life forms travel to Earth?

Citizen Staff Writer



Basic life forms that originated on other planets could have migrated to Earth aboard meteorites, a University of Arizona researcher said.

“I’m talking about microbes, bacteria,” said H. Jay Melosh, UA Regents’ professor of space sciences at the Lunar and Planetary Lab. “I’m not talking about lizards or bunny rabbits.

“It’s not outrageous that life developed on Mars and came to Earth. It seems conditions on the surface of Mars were such that life could survive or originate earlier than we have evidence of a crust on Earth.”

Melosh will give a free public presentation at 4 p.m. Wednesday titled “Are We All Martians? The Meteoritic Exchange of Life Between Planets.”

“A lot of the concern about the origin of life looks at how life could have gotten started,” he said. “Maybe life came from somewhere else.”

He said that 1 ton of Martian material – much of it tiny – falls on Earth each year. Most of the material remains undiscovered as it appears similar to material generic to Earth, he said.

The exchange works both ways, but he said it is easier for Martian meteorites potentially carrying microbes and bacteria to reach Earth than vice versa.

“Rocks from Mars are arriving all the time,” he said.

While scientists lack proof that Martian life forms have arrived on Earth, such an exchange is not only possible, but inevitable, he said.

“We have a general idea that life may have started on Mars,” he said. “We need to find living microbes or fossil microbes.”

This may be simpler on Mars. If analysis of life forms found on Mars show the same genetic code as terrestrial life, we would have to conclude we have a common past, he said.

“If we should find Martian life using the same dictionary for basic life processes we would have to assume we are related,” he said.

UA professor: ‘Are we all Martians?’


What: “Are We All Martians? The Meteoritic Exchange of Life Between Planets” lecture by H. Jay Melosh, UA Regents’ professor of planetary sciences

When: 4 p.m. Wednesday

Where: Room 201, UA Physics and Atmospheric Sciences building, 1118. E. Fourth St.

Cost: Free, public

Parking: Pay parking is available in the Sixth Street Parking Garage, 1201 E. Sixth St.

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