Q&A with Michel Denis, ExoMars flight director

A new multipurpose Russian communications satellite to be parked over the Atlantic Ocean is awaiting launch Monday aboard a Proton rocket.

NASA’s Curiosity rover is studying sand dunes towering up to two stories tall, returning new images showing a rippled landscape that represents a case of still-active geology on the red planet.

The solar wind, the million-mile-per-hour stream of charged particles blasted away from the sun, is slowly but surely stripping away Mars’ atmosphere and likely played a major role in turning the red planet from a habitable world in the distant past into the dry, frozen wasteland seen today, scientists said Thursday.