Do you think there might be life on other planets?

Do you think aliens are real? The movie Independence Day showed us aliens that wanted to destroy us and our planet. Fortunately, these kinds of aliens are not real, but do make books and movies more exciting! However, real-life scientists are busy searching for life forms that may exist on other planets.

Last year, scientists made an exciting discovery when they found a meteorite from the planet Mars. Meteorites are rocks which fall to Earth from outer space. As these rocks pass through Earth's atmosphere, they often catch fire. At nighttime, you can often see meteorites falling to Earth as "shooting stars". This meteorite, named ALH 84001, is very special because it contains chemicals and structures that look like bacteria we have on Earth. Does this mean there's life on Mars? We don't really know the answer yet, but you can be sure there are many scientists searching for clues!

Do you think there might be life on other planets?

Recently, there has been a great deal of interest in the idea that we might not be alone in the Universe. This isn't really surprising when you consider all the excitement of the Mars Pathfinder Mission and the fact that some of the most successful movies in the last year have featured aliens in lead roles (Contact, Men in Black, Independence Day). Much of this renewed interest is also due to last year's discovery of a meteorite from the planet Mars.

Scientists say that 16 million years ago, a giant asteroid crashed into the planet Mars. The impact was so great that chunks of rock were thrown from the Martian surface into outer space. One of these rocks later fell to Earth as a meteorite and was found last year in Antarctica. Meteorites are simply rocks which fall to Earth from outer space. As these rocks pass through Earth's atmosphere, they often catch fire and can be seen at nighttime as "shooting stars".

This particular meteorite, named ALH 84001, is special because it contains structures and compounds that resemble bacteria we have on Earth. Does this mean there once was (or, could still be) life on Mars? We don't really know the answer yet, but you can be sure there are many scientists searching for more clues!

Do you think there might be life on other planets?

With the recent release of several movies featuring aliens in lead roles (Contact, Men in Black, Independence Day), the groundbreaking achievements of the Mars Pathfinder Mission, and the concurrent celebration of the 50th anniversary of the "Roswell Incident", it's not surprising that so many people are once again asking the big question, "Are we alone?".

Much of the newfound interest in the possibility of life of other planets can be credited to the recent discovery of 4.5 billion-year-old Martian meteorite, ALH84001. A team of scientists, headed by Dr. David McKay, found microscopic structures in the meteorite that resemble bacteria found here on Earth. Mineral grains and organic chemical compounds were also observed near these structures that are similar to those found in association with certain bacteria on Earth. Scientists believe that the now famous chunk of rock was dislodged from the surface of Mars 16 million years ago by an enormous asteroid impact. The rock then travelled through space for several years before falling to earth as a small meteorite in Antarctica 13,000 years ago.

To date, the Martian meteorite is the best evidence we have for the existence of life on another planet. Part of the problem with searching for other life forms may be the fact that we don't necessarily know what we're looking for. Our standard concept of "life" is based on carbon and water. But as Dr. David Grinspoon states, "We simply do not know if that is the only chemical system that can make life, because the only example of a biosphere we have is our own."

Last modified prior to September, 2000 by the Windows Team

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