Tag: Mark Richards

  • Nation & World

    Twice doomed?

    Growing evidence points to a role for volcanoes in dinosaur extinction, said planetary scientist Mark Richards in a Harvard lecture.

    4 minutes
  • Nation & World

    Oceans are back on Mars

    Since spacecraft sent back the first close-up images of Mars more than 30 years ago, some experts have insisted that oceans once existed on the now dry, cold planet. Critics have maintained for decades that such an idea is the product of unrestrained imaginations. Now, a study published in today’s (June 14) issue of the…

    5 minutes