Phytoplankton, microscopic plant-like organisms, bloom in the North Atlantic Ocean in September. | (NASA image by Norman Kuring, using VIIRS data from the Suomi National Polar-orbiting Partnership)

An aerial view of Australia in October. | (NASA)

A small section of the expanding remains of a massive star that exploded about 8,000 years ago. | (NASA/ESA/Hubble Heritage Team)

A relatively recent impact crater on Mars. | (NASA/JPL/University of Arizona)

An expanding shell of debris from a massive star that exploded in the Large Magellanic Cloud. | (NASA/CXC/SAO)

An aerial view of the vein-like desert landscape of Oman, in the Middle East. | (NASA)

The sun is alight with solar flares on Jan. 1, 2015. The dark space on the southern end is called a coronal hole, where the sun's magnetic field reaches out into space instead of looping back toward the surface. | (NASA/SDO)

An aerial view of small cays in the Bahamas and the prominent tidal channels cutting between them. | (NASA)

The spectacular cosmic pairing of a star and its surrounding nebula, in the constellation Sagittarius, 15,000 light years away. | (ESA/Hubble & NASA, Acknowledgement: Judy Schmidt)