Age dispute over certain Mars meteorites may be settled

Los Angeles Times : Recently there has been some disagreement over the age of certain meteorites from Mars. Meteorites are important to scientists because they help further the study of Mars’s geology and formation, which could in turn indicate whether life ever existed on the planet. Desmond Moser of Western University in Ontario, Canada, and colleagues set out to ascertain that shergottites, a type of meteorite, were as young as many believed them to be—about 150 million to 250 million years old. If so, shergottites would be evidence that there had been recent volcanic activity on the planet and thus sufficient heat energy to have supported life. By measuring the isotopic ratios of radioactive elements in very tiny deposits, called baddeleyites, in the meteorites, the researchers confirmed that the shergottites were indeed formed about 187 million years ago.