Saturn Moon's Icy Secrets Shine Bright in New NASA Images (SPACE.com)

New details about Enceladus, one of the icy moons orbiting Saturn, are revealed in new images of the bright and shimmering cosmic body.

The snapshots highlight some of the grooves in Enceladus' south polar region, including unexpected textures in the moon's ice. The photos, taken by NASA's Cassini spacecraft on Nov. 6, are the highest-resolution images of this region obtained so far, according to NASA officials.

The new images of Enceladus come from data collected by a special radar instrument on Cassini, called the synthetic aperture radar.

The area photographed by Cassini does not include Enceladus' famous "tiger stripes," which are huge fissures on the moon's ice-covered surface that eject plumes of ice particles and water vapor. These icy geysers cover regions just a few hundred miles away from the stripes, NASA scientists said.

Researchers are scrutinizing an area on Enceladus that appears to have a very rough surface texture that glimmers peculiarly bright in Cassini's radar images. This patch is located at around 63 degrees south latitude and 51 degrees west longitude. [Video: Clearest Enceladus Views Yet Nabbed by Cassini Radar]

"It's puzzling why this is some of the brightest stuff Cassini has seen," Steve Wall, deputy leader of Cassini's radar team at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "One possibility is that the area is studded with rounded ice rocks. But we can't yet explain how that would happen."

Scientists are also investigating an area where Cassini spotted grooved, water-ice bedrock. The spacecraft's images reveal unusual undulations and intricate patterns that have not previously been seen. This area is located at around 65 degrees south latitude and 293 degrees west longitude on the icy moon.

Cassini's observations also reveal a central groove in this area that is about 2,100 feet (650 meters) deep and 1.2 miles (2 kilometers) wide, with sides that slope at an angle of about 33 degrees.

Enceladus is the sixth-largest moon around Saturn, and new images of the satellite show some similarities to Titan, the largest moon orbiting the ringed planet.

The western foothills in the so-called Xanadu region of Titan are also very bright, as are regions surrounding a large impact crater called Sinlap. Whether these luminous areas shine because of the same or very different processes will be the subject of research as scientists continue to learn more about the moons of Saturn, NASA officials said.

NASA's Cassini spacecraft was launched in 1997 and arrived at Saturn in 2004. The spacecraft carried the European Space Agency's Huygens lander, which landed on Titan soon after Cassini arrived in orbit around the ringed planet.

In 2008, Cassini completed its primary mission to explore Saturn, its rings and moons. Since then, the mission has been extended twice, most recently to 2017.

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Dusty Nearby Galaxy Blazes Bright in Hubble Photo (SPACE.com)

A dusty galaxy neighboring our own Milky Way shines bright and brilliant in an eye-catching new photo from the Hubble Space Telescope.

The image, released Thursday (June 16), is a close-up of the galaxy Centaurus A, which is also known as NGC 5128 and is located about 11 million light-years from the Milky Way. Dust crosses the entire galaxy in a huge stripe, obscuring much of Centaurus A's heart in the visible range of the light spectrum.

The Hubble photo, however, cuts through the cloud, because it doesn't just rely on visible light. The image also incorporates observations in ultraviolet and near-infrared wavelengths. This latter part of the electromagnetic spectrum allows astronomers to peek behind dusty cosmic curtains. [See Hubble's photo of Centaurus A]

Centaurus A is somewhat warped, leading researchers to believe that it collided and merged with another galaxy at some point in the past. The shockwaves from this event likely caused hydrogen gas to coalesce and sparked intense star formation in some areas, researchers said. These star-formation regions are visible as red patches in the Hubble photo.

The galaxy's compact nucleus contains a highly active supermassive black hole at its center. Powerful jets blast huge amounts of radio and X-ray radiation into space. These jets aren't visible in the new image, however, as Hubble's instruments aren't designed to pick up these wavelengths of light.

Centaurus A is relatively nearby in astronomical terms, and it is also quite bright. This combination makes the galaxy an attractive target for amateur astronomers in the Southern Hemisphere, where it is visible. Stargazers can see the galaxy through binoculars, while larger amateur telescopes can make out some of Centaurus A's distinctive dust lanes, researchers said.

Hubble took the image in July 2010 with its most advanced instrument, the Wide Field Camera 3. Hubble, a joint effort between NASA and the European Space Agency, has been snapping amazing images of the universe from orbit since its launch in April 1990. The telescope has been repaired five times over its long life, but it's expected to keep going strong until at least 2014.

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Exploded Star's Guts Shining Bright Again, Photo Shows (SPACE.com)

The glowing entrails of an exploding star, thought to have faded over time, now appear to be lighting up again, a new Hubble Space Telescope photo reveals.

NASA released the new Hubble image of the well-known star explosion, called Supernova 1987A, today (June 10). The photo shows the closest supernova explosion witnessed in almost 400 years. This has allowed astronomers to study it in unprecedented detail as the outburst evolves.

In the latest study of Supernova 1987A a team of astronomers announced that the debris from the explosion that had faded over the years is brightening. This suggests that the star explosion, which is located 165,000 light-years away in the Large Magellanic Cloud (a close neighbor of our own Milky Way galaxy),  is turning into a so-called supernova remnant. [See Hubble's new photo of Supernova 1987A]

The research is detailed in the June 9 edition of the journal Nature.

Supernovas typically transition into remnants when the exploded material starts to fade, but the brightness increases due to interactions between the debris cloud and surrounding gas. This cosmic shift is usually difficult for astronomers to study, but due to the relatively close proximity of the Large Magellanic Cloud, astronomers have been able to make detailed observations of Supernova 1987A periodically from 1994 to 2009.

"Supernova 1987A has become the youngest supernova remnant visible to us," said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "It's only possible to see this brightening because SN 1987A is so close and Hubble has such sharp vision."

Kirshner leads a long-term study of SN 1987A using the Hubble Space Telescope. Since its launch in 1990, Hubble has provided a continuous record of the changes in the supernova.

In the new Hubble image, SN 1987A is surrounded by a ring of material that blew off the star thousands of years before it exploded. The ring extends about one light-year (about 6 trillion miles or 9.5 trillion km) across. Inside that ring, the star's guts are rushing outward in an expanding debris cloud.

Most of the light from the supernova comes from radioactive decay of elements that were created in the explosion. This light fades over time, but the brightening of SN 1987A's debris suggests that a new power source is lighting it.

The debris of 1987A is beginning to impact the surrounding ring, which is creating powerful shock waves that produce X-rays that can be observed by NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and the heated shock waves are making it glow. This same process powers well-known supernova remnants in our own galaxy, like Cassiopeia A.

Furthermore, since SN 1987A is still young, astronomers can study the remnants of the explosion to decode its history.

Eventually, that history will be lost when the bulk of the expanding stellar debris impacts the surrounding ring and shreds it, researchers said. But, until then, SN 1987A offers astronomers the opportunity to watch as a supernova changes, they added.

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