Page 51 - (DK) Eyewitness - Mars

Meteorites from Mars A GIANT IN AFRICA
Martian meteorites have been
discovered on most continents,
especially in Africa. Most
meteorites weigh less than
a pound (450 g). This
55-pound (25 kg) stone
(right) from Libya’s
Sahara Desert is part of
the largest known
Martian meteorite,
which weighs about
210 pounds (95 kg).
Named Dar al Gani, this
meteorite shattered into
hundreds of fragments
upon impact. The
photograph at left shows
the Sahara Desert, where
the meteorite was found.

Finding Martian rocks in Antarctica

One of the best places on Earth to look for meteorites is the frozen southern
continent of Antarctica. To prove Martian origins, geochemists look for
microscopic air bubbles in meteorites with the same exact mixture of gases as
the Red Planet’s atmosphere.

Thiel Mountains Wisconsin Range-
Patuxent Range Scott Glacier
Formation
resembling microbe

OLDEST METEORITE
Found in the Allan Hills during
the 1984–1985 Antarctic summer,
Beardmore this meteorite is cataloged as ALH
84001. In 1994, researchers found
it to be 4.5 billion years old, the
most ancient Martian meteorite
Darwin-Byrd Glacier yet known.
(Meteorite Hills)
EVIDENCE OF LIFE?
This electron microscope image of a
METEORITE SITES carbonate formation in ALH 84001
Antarctica’s main meteor sites are shows wormlike shapes that some
grouped in mountainous regions. One scientists believe could be fossilized
site, nicknamed “Meteorite Hills,” has Allan Hills-David microbes—microscopic life-forms. Other
yielded many important finds since the Glacier (Elephant Moraine) scientists disagree, saying they are inorganic
1970s. Meteorites once embedded in ice mineral formations. Heated debates continue to
are often found along the edges of glaciers. rage over these unexplained structures.

CARBONATES IN ALH 84001
A microscopic cross-section of
ALH 84001 shows carbonate
formations, which contain the
controversial wormlike
structures. Carbonate
structures form in water,
suggesting that ALH 84001
was almost certainly exposed
to water for a long time.

A FIND ON ANTARCTICA
Every year, in the summer months, international meteorite
hunters stage expeditions to Antarctica. This 2001 field
team from the Antarctic Search for Meteorites (ANSMET)
organization examines a newly discovered space rock.
Meteorite ANSMET is sponsored by the U.S. National Academy of
on ice surface Sciences, NASA, and the Smithsonian Institution.

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