The Des Moines Register March 14, 2003

ISU professor says moon holds secrets of early Earth

by Brandon Babcock

Ames, Ia. - An Iowa State University professor wants astronauts to go back to the moon.

He says the world could be surprised by what's there - 4 billion-year-old remnants of Earth, Mars and Venus that could redefine the history of the solar system and mankind.

"There is a chance to get our hands on new, empirical evidence that isn't available on the Earth anymore," said Guillermo Gonzalez, an assistant professor of physics and astronomy who headed the research team. "That's waiting for us on the moon."

Rocks ejected intact from Earth's gravitational field by asteroid and comet impacts found their way through space to the moon, according to the team's research, in much the same way that lunar rocks have been found on Earth.

A published NASA- and National Science Foundation-sponsored research paper discussing this topic speculates that astronauts could discover more samples of Mars or the first samples of early Venus.

For that possibility alone, Gonzalez says astronauts must go back despite the Columbia explosion in early February. The scientific benefits would outweigh the risks.

"Finding a rock from Venus would be like finding the Hope diamond," he said.

Venus can't be explored because of its surface. Information on Mars is based on so few samples that any single find would contribute huge amounts of knowledge to its history, Gonzalez said.

To determine just how much Earth rock has reached the moon, the researchers mathematically simulated the gravitational results of hundreds of particles randomly leaving the Earth. The results show seven parts of Earth per million, more abundant than diamonds on Earth, Gonzalez said.

John Armstrong, a graduate assistant at the University of Washington, is credited by Gonzalez with doing the majority of the paper's research.

Armstrong said any voyages to Mars should wait.

"The fact is, the moon is right there, and it can tell us everything we need to know about the solar system," he said.

Critics of the research argue that nothing could survive the violence required for a rock to be blown off a planet, exit its thick atmosphere and not be destroyed upon impacting another body.

Armstrong and Gonzalez admit it is a legitimate worry.

"A lot of the criticism we've been getting is, "Can this material survive impact with the moon, and could it stay there?" " Armstrong said. "Before we found Mars meteorites on the Earth, they said that couldn't happen, either."

File Date: 03.25.03