What was special about the meteorite ALH84001?
What was special about the meteorite ALH84001?
ALH84001 is thought to be one of the oldest Martian meteorites, proposed to have crystallized from molten rock 4.091 billion years ago. Chemical analysis suggests that it originated on Mars when there was liquid water on the planet’s surface.
What is ALH84001 made of?
ALH84001 is a coarse-grained, cataclastic orthopyroxenite (97% orthopyroxene, 2% chromite, ~1% maskelynite, 0.15% phosphate) with minor augite, olivine, pyrite and secondary Fe-Mg-Mn-Ca carbonate. The igneous minerals are essentially unzoned whereas the carbonate is highly zoned in composition. Mason et al.
When did NASA find fossils on Mars?
1996
When Nasa’s Mckay presented his pictures of Martian fossils to the press that day in 1996, one of the millions of people who saw them on television was a young British environmental microbiologist named Andrew Steele.
How old is the ALH84001 meteorite in years?
…meteorite is another Antarctic specimen, ALH84001. This rock, an orthopyroxenite, has a crystallization age of about 4.5 billion years, which is roughly the same age as asteroidal meteorites ( see below The ages of meteorites and their components), but several of its properties clearly tie it to the other Martian meteorites.…
Where was the meteorite found in the Allan Hills?
Allan Hills 84001 (commonly abbreviated ALH84001) is a fragment of a Martian meteorite that was found in the Allan Hills in Antarctica on December 27, 1984, by a team of American meteorite hunters from the ANSMET project.
How is ALH 84001 related to the Martian atmosphere?
The strongest evidence for their martian origin is that they, including ALH 84001, contain traces of gas that is just like the martian atmosphere. We know the composition of the martian atmosphere, because the Viking Lander spacecraft analyzed it, on Mars, in 1976.
How did the asteroid ALH 84001 change its orbit?
After it left Mars, ALH 84001 orbited the Sun on its own, like a small asteroid. It started out with an orbit nearly like Mars’. But its orbit changed each time it passed close to Mars or collided with an asteroid. Also, gravity from the planets (especially from enormous Jupiter) slowly nudged ALH 84001 farther and farther from Mars.
