Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2014 April 6
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Fresh Tiger Stripes on Saturn's Enceladus
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: Do underground oceans vent through the tiger stripes on Saturn's moon Enceladus? Long features dubbed tiger stripes are known to be spewing ice from the moon's icy interior into space, creating a cloud of fine ice particles over the moon's South Pole and creating Saturn's mysterious E-ring. Evidence for this has come from the robot Cassini spacecraft now orbiting Saturn. Pictured above, a high resolution image of Enceladus is shown from a close flyby. The unusual surface features dubbed tiger stripes are visible in false-colour blue. Why Enceladus is active remains a mystery, as the neighbouring moon Mimas, approximately the same size, appears quite dead. Most recently, an analysis of slight gravity deviations has given an independent indication of underground oceans. Such research is particularly interesting since such oceans would be candidates to contain life.

Tomorrow's picture: hubble orion


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