Mysterious flashes of light from Mars have been dismissed as illusions having more in common with Loch Ness monster sightings than hard science. But a team of accomplished amateur astronomers has now done something Nessie fans can only dream of: They predicted when one legendary flash would recur and then captured it on video tape during an expedition to the Florida Keys last week.
When bright light flashed from a hook-shaped martian feature called the Edom Promontorium in 1958, some overeager scientists suggested that martians with mirrors were signaling Earth. But the consensus was that a favorable planetary alignment caused sunlight to reflect from water crystals in the martian atmosphere.
Thomas Dobbins, an amateur astronomer and author of the book Video Astronomy, first read about the flashes as a child. Last year he decided to calculate when the 1958 alignment of Earth and Mars would recur. To his surprise, the computer spit out early June 2001. "I felt like stripping off my clothes and running down the street yelling 'Eureka!,' " Dobbins says. He later decided on a more modest course of action: gather top-notch astro-imagers in Florida to photograph the flashes.
His efforts paid off 7 June at 2:40 a.m. when the team observed flares glinting from the edge of the Edom Promontorium for nearly 90 minutes. The flare, and additional flares on 8 June, were captured by a video camera mounted on a 12-inch telescope, reports the team in the 8 June International Astronomical Union Circular 7642.
Scientists have no doubts about the reality of the flares, but they aren't sure about the cause. The favorite explanation--clouds of ice crystals--requires some good fortune. "If it is from fog or clouds, then either they got very lucky or the clouds recur regularly," says Tim Parker, a planetary scientist at the Jet Propulsion Laboratory in Pasadena, California. Parker suggests testing the theory by searching for similar glints with the Mars Observer.
IAU Circular Announcement
Software used to predict planet alignment is available at this reference resource
Association of Lunar and Planetary Observers
Information about the sun glint prediction