NASA scientists are puzzled by a new image taken by its Dawn spacecraft that captured .

The images of Ceres, located between Mars and Jupiter, show what appear to be tiny bright areas in a circular depression. NASA scientists speculate that the spots, captured Feb. 19 from a distance of nearly 29,000 miles, are some kind of volcanic origin, but they aren't sure.

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"The brightest spot continues to be too small to resolve with our camera, but despite its size it is brighter than anything else on Ceres. This is truly unexpected and still a mystery to us," said Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research, Gottingen, Germany.

NASA said the Dawn spacecraft will enter into Ceres' orbit March 6 and will capture even sharper images of the mysterious spots and the 590-mile-wide planet.

MORE ON WEATHER.COM: 100 Images from NASA's Hubble Space Telescope

April 24 marks the 25th anniversary of the Hubble Telescope. To celebrate, NASA and the European Space Agency, which jointly run the telecope, released this image of the star cluster Westerlund 2. (NASA/ESA/Hubble Heritage Team/A. Nota/Westerlund 2 Science Team)