Mars clues in Mexican crater?
2008-08-01 14:14
Merida - A prehistoric
crater left by an asteroid collision in Mexico's Yucatan
Peninsula could yield clues about what Mars was like billions
of years ago, a Nasa scientist says.
Nasa planetary geologist Adriana Ocampo is digging up rocks
buried deep under south-eastern Mexico for hints about what
impact craters can reveal about planet formation, and says her
work could shed light on a giant crater on the surface of
Mars.
Astronomers have been puzzled for decades about a huge dent
on the surface of Mars - the largest known crater in the solar
system - and new evidence last month suggests it was caused by
the impact of an asteroid the size of the moon.
The Mexican crater, known as Chicxulub, was created when an
asteroid that smacked into Earth 65 million years ago in a
catastrophe that wiped out around half the planet's species and
was maybe responsible for the dinosaurs becoming extinct.
Studying the debris spewed by the collision may answer
questions about radical changes in atmosphere that can result
from massive asteroid hits, Ocampo, a Colombian based at Nasa's
Jet Propulsion Laboratory in California, told Reuters.
'Natural laboratory'
She has
been studying the Yucatan crater for a decade.
"It's a natural laboratory because of its similarities to
what we can find on other planets like Mars where humans can't
go," Ocampo said of Mexico's smaller crater.
The crater on Mars, measuring 8 530 km
across, is so big that it has left half the planet at a lower
elevation.
Mexico's crater is a much smaller 160 km in
diameter and is now half a mile underground, where rocks and
earth have buried it over millions of years.
Space geologists
believe the asteroid hit in the Caribbean Sea, probably causing
a huge tsunami.
Information from Chicxulub could also give clues about
whether or not there was water on the surface of Mars long
after the planet was dented by the massive asteroid hit.
Scientists have detected frozen water on the surface of the
red planet. Martian seas could have disappeared when the planet
was bombarded by smaller meteors that changed its atmosphere
and dried it out, Ocampo said
She is looking for similarities between the Yucatan crater
- formed when southern Mexico was under the sea - and smaller
craters on Mars to see if she can detect similar patterns
formed by water.