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Clues To Possible Life On Europa May Lie Buried In Antarctic Ice

Marshall Space Flight Center Press Release

Clues to possible life on Europa may lie buried in Antarctic ice

March 5, 1998: More than a century ago, science fiction pioneer Jules Verne
wrote about people swept "Off on a Comet" and into space where they lived
more or less happily ever after.

Verne's 1877 book (also published as "Hector Servadac") was a bit fanciful,
but it had an element of truth: life may have hitchhiked across the solar
system. The proof may be found at the ends of the Earth. This week, American
and Russian scientists are examining deep ice from the Antarctic and hoping
to find clues that fungi, bacteria, and even diatoms could survive
conditions in icy solar system bodies. This would help make the South Pole
one of the first destinations for the growing field of astrobiology.

"It's possible to say that ancient impacts of asteroids on the [Antarctica]
Earth could have ejected soil, rocks, and seawater containing
terrestrial microorganisms into space, and that they may have made it to
other places in the solar system," explained Richard Hoover at NASA's
Marshall Space Flight Center. Hoover is an X-ray astronomer who is also is
internationally known for his work on diatoms and a firm believer that
living microorganisms locked in ice have a chance of remaining viable for
long periods in outer space.

The debate over whether the Antarctic Allan Hills meteorites brought life
from Mars (or were contaminated by life on Earth) is the best known case.
Hoover said that other evidence abounds, including asteroids striking the
Earth or Mars and blasting materials into space, the survival of
streptococcus bacteria on the Surveyor 3 moon lander, and the survival of
microorganisms inside Antarctic ice.

The possibilities expanded this week when NASA released new images and data
that Europa, one of Jupiter's larger moons, slush and perhaps liquid water
near the surface. That raises the intriguing possibility that Europa may
harbor life.

Discoveries on the Earth over the last few years show that life thrives or
can be preserved in a range of "hostile" conditions, from volcanic vents
deep in ocean trenches, to ice more than 400,000 years old, to Siberian
permafrost more than 5 million years old.

This week, Hoover and Dr. S. S. Abyzov of Russia's Institute of Microbiology
of the Russian Academy of Sciences in Moscow are examining ancient ice
drilled at Russia's Vostok (East) Station about 1,000 km (1,600 mi) from the
South Pole. Eventually, they hope to examine water taken from inside a lake
- liquid, not ice - discovered under Vostok Station in 1996.

The first samples being examined are from 386 meters (1,266 ft) down; the
deepest in this set is from 1,249 meters (4,097 ft). Samples from as deep as
3,610 meters (11,840 ft) are on their way from Vostok to the Institute of
Microbiology. Abyzov says that portions will be brought to Marshall later
this year.

Russian scientists have been drilling at Vostok since 1974. In 1996, seismic
and other tools revealed the lake's presence in 1996. Lake Vostok is
overlaid by about 3,710 meters (12,169 ft) of ice and may be 500,000 to 1
million years old. Since the discovery, drilling has gone slowly while
procedures are worked out to keep it pristine. No one has seen or sampled
the lake - the deepest ice sample is from 100 meters (328 feet) above the
liquid surface - nor is anyone sure why it is liquid, hence the scientific
curiosity. (Check below for links to stories about Lake Vostok.)

While Lake Vostok holds clues about life on Earth, it also is a
good model for conditions on Europa (the image links to the latest
news from Europa). The lake is about 48 by 224 km (30 by 140 mi) in size -
about the size of Lake Ontario - and 484 meters (1,600 ft) deep. Recent data
indicate that it has about 50 meters (165 ft) of sediment at the bottom.

"Recent research [shows] that extremely severe conditions of cosmic
environments do not exclude the possibility that microorganisms may exist in
anabiotic states at high altitudes in interplanetary space," Abyzov wrote in
a recent paper. The only way to resolve the question is to use the Antarctic
as a model for conditions in comets, the Martian ice caps, and other icy
moons orbiting Jupiter and Saturn.

At Vostok station in 1975, Abyzov discovered bacteria, fungi, diatoms, and
other microorganisms which were blown to Antarctica by winds from lower
latitudes. The numbers of the organisms at different depths, and thus
different ages of the ice, change with major climate changes on the Earth.
Thus, the ice also serves as a time capsule, preserving specimens of life as
far back as 500,000 years. This offers the potential for studying how
genetic material changes over the centuries.

Abyzov brought his samples to Marshall to use the Environmental Scanning
Electron Microscope, or ESEM, a relatively new tool that Marshall uses to
analyze how materials fail and break. It was originally designed to analyze
biological specimens in their natural environment, without coating them in
gold to make them reflective. And that's ideal for observing whatever is in
the ice. It also uses an X-ray scan to analyze the elements in a target, an
important step in determining whether an object is organic.

The ice specimens will be analyzed at Marshall over the next week, then
Abyzov will go to the Jet Propulsion Laboratory to work with another
colleague with different analytical tools. Check back in a few days for a
follow-up story on what the ESEM finds.