Posted: Sat, Sep 28, 2002, 12:21 PM ET (1621 GMT)
Scientists have found evidence that the wobble, or change in tilt, of Mars has an affect on its climate. A team of US and French scientists, writing in the journal Nature, used high-resolution images of the planet's northern polar ice cap taken by Mars Global Surveyor to measure the layers of dust sandwiched in the ice. They linked the layers to changes in the planet's obliquity, which varies between 15 and 40 degrees. They found that the 350-meter section of layers studied were formed in the last one million years, and the current rate of deposition of material on the cap — 0.05 cm/year — suggests that the cap may be as little as five million years old. While the effects of wobble on climate had already been found on Earth, this is the first time a similar effect has been seen on another planet.

Related Links:

•  BBC article
•  AFP article
•  Scientific American article
•  Brown University press release