The planet Mars has gone through an ice age and is now warming up, scientists say. The findings are based on detailed radar measurements of ice caps on Mars. Isaac Smith studies the physical qualities of Earth and other planets -- or geophysics -- at the University of Texas. He told VOA about new research from scientists at universities in Texas, Colorado and Missouri. Their findings were published in the journal Science. Smith said Mars has ice ages, just like Earth has had. “The last ice age would have been about 600,000 years ago,” he told VOA. “And the next [ice age on Mars] is 500,000 [years] in the future.” Mars is often called the red planet. But, a few hundred thousand years ago, the scientists said, the planet was not so red. Their research suggests that Mars has been warming for the past 370,000 years.