Mars Odyssey Encounters Polar Vortex

NASA’s Mars Odyssey has encountered a strange, unexpected phenomenon as it slips over the red planet’s north polar region. An intense polar vortex has been detected, causing Mars’ atmosphere to be less dense than predicted for that area. Likened to a jet stream on Earth, the baffling high-latitude, planet-circling vortex is being carefully eyed by scientists. To what degree the newly found vortex alters the tempo of aerobraking is being evaluated.