Skywatch

  • September 22, 2005

    Episode 2: You've heard of the endless summer - how does an endless winter sound?

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    Shownotes

    New studies of Martian meteorites that have landed on Earth suggest that Mars has been colder than freezing for an extremely long time. Detailed chemical analysis of the Mars meteorites, including the famous ALH84001 meteorite from Allan Hills in Antarctica, shows the long-term temperature of those rocks as very cold. During the last 4 billion years, Mars was likely never warm enough for water to flow on the surface for extended periods of time.
    Mars meteorite ALH84001 [NASA/JSC]
    Mars meteorite ALH84001 [NASA/JSC]
    Mars has geologic formations that look like they could have been caused by water, including deep canyons and apparent, dried-up river beds. Researchers are trying to understand how much water was on Mars, and for how long. If the meteorite analysis is correct, the environment wouldn't have been right for life to develop on Mars - unless it evolved in the first half-billion years of Mars' existence.