Swirling plankton blooms create electric-blue eddies off the coast of Ireland, as seen in a satellite picture taken in May and released this week by the European Space Agency.
Phytoplankton are microscopic marine plants that drift on or near the ocean's surface. The annual spring plankton blooms in the North Atlantic—driven by natural conditions—can color the water enough that the hordes of tiny plants become visible from space.
Omega Centauri is visible to the naked eye and has been known of since ancient times. Originally thought to be a star, astronomers in the 1800s identified the object as a blob made of millions of stars bound together by gravity.
More recent studies have suggested that there's a black hole at the center of the cluster. Since it's thought all galaxies have black holes at their hearts, it's possible Omega Centauri should be once again reclassified, this time as a stripped-down dwarf galaxy, according to NASA.
MetOp-B is the second of three European meteorological satellites being launched to provide continuous data on Earth's temperature, humidity, cloud cover, and atmospheric gases. MetOp-A launched in 2006, and MetOp-B is due to launch in 2012, followed by MetOp-C in 2016.
Photograph courtesy ESA
Caught between light and dark, a "tiger stripe" fissure on Saturn's moon Enceladus comes into stark relief in a picture taken by NASA's Cassini spacecraft during an August 13 flyby.
The tiger stripes near Enceladus's south pole are the sources of the moon's icy geysers, which spew water vapor and organic particles into space.
A Perseid meteor shoots across the night sky over the European Southern Observatory's Paranal Observatory in Chile, which appears bathed in the reddish glow of the setting moon in a long-exposure picture taken the night of August 13-14.
The annual Perseid meteor shower is best visible in the Northern Hemisphere, because the meteors seem to radiate from the constellation Perseus in the northern sky. But the exceptionally dark nights in Paranal allowed photographer Stéphane Guisard to capture a few bright streaks from the platform of the observatory's Very Large Telescope.
Thin clouds partially veil a chunk of ice four times bigger than Manhattan, which broke off the Petermann glacier along the northwest coast of Greenland on August 5. NASA's Terra satellite spied the newborn iceberg on August 12.
Although it's not unusual for icebergs to calve off Petermann glacier, scientists are watching this massive ice chunk closely to see if it creates a sea ice pileup in Baffin Bay or poses any danger to Arctic shipping lanes.
At a distance of 114 million miles (183 million kilometers), Earth and the moon appear as bright dots against a background of stars, as seen in a picture taken by NASA's MESSENGER spacecraft and released August 17.
MESSENGER is currently maneuvering toward a stable orbit around Mercury, the closest planet to the sun. Along the way, the probe has been searching for vulcanoids, small rocky objects theorized to exist in orbits between Mercury and the sun.
No vulcanoids have been detected so far, but MESSENGER will be the first NASA craft to orbit Mercury—putting it in a unique position to look for small, faint objects.