On this day in space: Dec. 27, 1984: Famed Allan Hills Mars meteorite found in Antarctica

On Dec. 27, 1984, one of the most famous Mars meteorites was found in Antarctica.

The meteorite, known as Allan Hills 84001, was found in Allan Hills, which is a group of hills in Antarctica. It was found by an American team of meteorite hunters from a National Science Foundation program called ANSMET, which stands for the Antarctic Search for Meteorites.

Weighing in at just over 4 lbs., this space rock is considered to be one of the oldest Martian meteorites ever found on Earth. Scientists estimate that it crystallized from molten rock more than 4 billion years ago, when Mars still had liquid water on its surface. It also has been the source of controversy about the search for life on Mars that continues to this day.

Scientists determined that the meteorite probably came from an area called Valles Marineris. To figure that out, they compared spacecraft data on the chemical composition of Mars with the chemical composition of the meteorite. Scientists think that the meteorite was ejected into space when Mars got hit by a meteor about 17 million years ago, and that it hit the Earth about 13,000 years ago.

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