• Spot the specks of Saturn's moons

    NASA / JPL-Caltech / SSI

    Two of Saturn's more than 60 moons join the ringed planet in this scene, captured by the Cassini orbiter on Jan. 19 and released on April 30. Tethys appears as a small white dot above the rings on the far left of the image. Enceladus appears as a smaller bright speck beside the planet. The rings cast wide shadows on the planet's southern latitudes.

    By Alan Boyle, Science Editor, NBC News




    Two of Saturn's moons are dwarfed by the giant planet and its rings in this family portrait from the Cassini spacecraft, which will mark its eighth year in Saturnian orbit in July. This image was put out by the Cassini imaging team on Monday, just a little too late to make our Top 20 roundup for the Month in Space Pictures — but it's worth passing along as a bonus prize.

    You can see 660-mile-wide Tethys as a white dot toward the left edge of the image, and 313-mile-wide Enceladus as a smaller bright speck beside the planet. Tethys is thought to be composed mostly of water ice with a bit of rock mixed in, while Enceladus is a very special case: Cassini has repeatedly documented geysers of water ice spewing from fissures in that moon's surface — suggesting that liquid water and perhaps even living things may lie beneath. It'll be up to a future probe to plumb the mysteries of Enceladus more deeply.

    Saturn's rings are seen nearly edge-on, and in this picture they're casting wide, curved shadows on Saturn's southern hemisphere. Bad Astronomy's Phil Plait says he can't help noticing the thin white ribbon of clouds stretching across the planet's northern hemisphere. Those may be the remnants of a monster storm that wrapped itself around the globe for months, starting in late 2010. "Our gas giants don't screw around," he writes. "When they do something, they do it big."

    And when we do the Month in Space Pictures slideshow, we do it big as well. Click on the image below to see some of the best out-of-this-world views from the month of April. You'll find shots from the final flights of the shuttles Discovery and Enterprise, photos of weird phenomena on Mars and Uranus, and even a UFO (Galaxy, that is). If you want to find out more about the stories behind the pictures, leave a comment and I'll try to point you in the right direction.

    Slideshow: Month in Space: A blaze of glory

    NASA/SDO/AIA

    Click through a solar eruption, the final odyssey of the shuttle Discovery and other outer-space highlights from April 2012.

    Launch slideshow

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

  • Mercury in perspective

    NASA / JHUAPL / CIW-DTM / GSFC /

    This color-coded perspective view shows elevations in the ancient volcanic plains that lie the northern high latitudes of Mercury, as revealed by NASA's Messenger spacecraft. Purple colors are low and white is high, spanning a vertical range of about 1.4 miles (2.3 kilometers).

    Like to see more images like this? Then check out Month in Space slideshow.

     

     

     

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  • Stunning views of the sun ... and Discovery?!

    By Jonathan Woods, msnbc.com

    Amateur astrophotographer Alan Friedman has done it again. Adding to an already impressive collection of outer space images, he just published two more magnificent photos of the sun. First, here's a view of a gassy prominence flaring off the sun like a cloud:

    Alan Friedman

    This section of the solar disk was imaged at the Winter Star Party on West Summerland Key in Florida, in the midst of 30 mph winds. The massive detached solar prominence was visible for hours. Skies were quite steady, despite the wind.

    To add some perspective on the sheer magnitude of what Friedman is documenting, look at the dark spot below the prominence. That spot is roughly twice the size of the Earth. 

    Using the same specialized equipment he used in October 2010 to produce the last set of breathtaking images, Friedman looks at the deep red end of the light spectrum to capture the emissions given off by hydrogen gas in the sun's atmosphere.

    He also came away with a historic glimpse of Discovery as it was docked to the International Space Station, during the space shuttle's final mission.

    Friedman said he captured the event, lasting just a fifth of a second, after making an 1,800-mile drive from Buffalo, N.Y., to the Winter Star Party in West Summerland Key, Fla.

    He went to the Florida gathering "for the steady skies, warm temperatures and the company of good astronomy friends." But when he learned that the International Space Station would cross paths with the sun, and that the sight would be visible 20 miles north of where the star party was being held, he felt compelled to document the flyover.

    "I jumped into the car with solar imaging gear, and we got set up just in time to catch it." he said. "I underestimated the narrowness of this event. We were about 5,000 feet south of the centerline in a good location... another 500 feet and we would have missed it entirely. Lucky day!"

    Alan Friedman

    Silhouetted by the sun, the space shuttle Discovery can be seen docked to the International Space Station during its final mission.

    Friedman talks with TODAY.com's Dara Brown about his latest work:

    More imagery of the sun and the shuttle:

  • NASA Earth Observatory

    Like rivers of liquid water, glaciers flow downhill, with tributaries joining to form larger rivers. But where water rushes, ice crawls. Alaska's Susitna Glacier revealed some of its long, grinding journey when NASA's Terra satellite passed overhead on Aug. 27. This satellite image from Terra, released Oct. 20, combines infrared, red, and green wavelengths to form a false-color image. Vegetation is red, and the glacier's surface is marbled with dirt-free blue ice and dirt-coated brown ice. Infusions of relatively clean ice push in from tributaries in the north.

    Rivers of ice

    Get eye-opening perspectives of the moon, the planets and the wider cosmos in our roundup of outer-space imagery from October 2010.