NASA Administrator Charles Bolden, NASA personnel, and others, participate in a wreath laying ceremony as part of NASA's Day of Remembrance, Thursday, Jan. 26, 2012, at Arlington National Cemetery. Wreathes were laid in memory of those men and women who lost their lives in the quest for space exploration.

Larger image Photo Credit: NASA/Bill Ingalls

Suomi NPP's VIIRS instrument returned this hi-resolution full-disc image of the Earth from several passes made Jan. 4, 2012.

The Suomi National Polar-orbiting Partnership (Suomi NPP) mission represents a critical first step in building the next-generation Earth-observing satellite system that will collect data on both long-term climate change and short-term weather conditions.

This mosaic of images taken in mid-January 2012 shows the windswept vista northward (left) to northeastward (right) from the location where NASA's Mars Exploration Rover Opportunity is spending its fifth Martian winter, an outcrop informally named "Greeley Haven."

Opportunity's Panoramic Camera (Pancam) took the component images as part of full-circle view being assembled from Greeley Haven.

Using the APEX telescope, a team of astronomers has found the strongest link so far between the most powerful bursts of star formation in the early Universe, and the most massive galaxies found today. The galaxies, flowering with dramatic starbursts in the early Universe, saw the birth of new stars abruptly cut short, leaving them as massive -- but passive -- galaxies of aging stars in the present day. The astronomers also have a likely culprit for the sudden end to the starbursts: the emergence of supermassive black holes.

Solar flare seen by ESA/NASA SOHO satellite 23 January, shortly after a large M8.3-class solar flare occurred at 03:59 GMT. The flare caused a Coronal Mass Ejection that reached Earth in the afternoon of 24 January 2012. Credits: ESA/NASA

A new analysis of radar data from the international Cassini spacecraft has revealed regional variations amongst Titan's sand dunes. The result yields new clues to the giant moon's climatic and geological history.

Flying past Saturn's moon Dione, Cassini captured this view which includes two smaller moons, Epimetheus and Prometheus, near the planet's rings. The image was taken in visible light with Cassini's narrow-angle camera during the spacecraft's flyby of Dione on Dec. 12, 2011.

This encounter was the spacecraft's closest pass of the moon's surface, but, because this flyby was intended primarily for other Cassini instruments, it did not yield Cassini's best images of the moon.