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EarthSky // Page 3

Evidence for supernovas near Earth

A NASA sounding rocket has confirmed that the solar system is inside an ancient supernova remnant. Life on Earth survived despite the nearby blasts.

Will you catch the moon near Mercury after sunset tonight?

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Our sky chart shows the moon and the planet Mercury as they appear in North America, about 35 to 40 minutes after sunset. For the most part, the thin waxing crescent moon and Mercury sit too close to the glare of sunset to be visible from mid-northern latitudes and farther north. These two worlds will be hard to spot after sunset at northerly latitudes, even in binoculars.

People in the Southern Hemisphere should have an easier time catching the young moon and Mercury after sunset on August 27. For example, At Rio de Janeiro, Brazil, Mercury sets about one and one-quarter hours after sunset, and the moon sets about 2 hours after the sun. At Philadelphia, Pennsylvania, on the other hand, Mercury sets less than 45 minutes after the sun, and the moon sets about 50 minutes after sunset.

Best view yet of colliding galaxies in distant universe

A collision that took place between two galaxies when the universe was only half its current age. This picture combines the views from the Hubble Space Telescope and the Keck-II telescope on Hawaii (using adaptive optics) along with the ALMA images shown in red. Image credit: ESO, ALMA (NRAO/ESO/NAOJ); W.M. Keck Observatory; NASA/ESA

A collision that took place between two galaxies when the universe was only half its current age. This picture combines the views from the Hubble Space Telescope and the Keck-II telescope on Hawaii (using adaptive optics) along with the ALMA images shown in red. Image credit: ESO, ALMA (NRAO/ESO/NAOJ); W.M. Keck Observatory; NASA/ESA

Using telescopes on the ground and in space, astronomers have obtained the best-yet view of a galaxy collision that happened when the universe was half its current age.

Testing a space rover under Alaskan ice

Scientists test a device on an Alaska glacier that could be used to explore an icy moon of Jupiter.

Messier 8 is the Lagoon Nebula

Scott MacNeill captured this beautiful photo of M8 in August 2014.

Scott MacNeill captured this beautiful photo of M8 in August 2014. He wrote, “Here’s a fantastic capture of M8 – The Lagoon Nebula I shot at Frosty Drew Observatory in Charlestown, Rhode Island, USA … I focused on M8 for a while as it was looking so sexy!”

The Lagoon Nebula, also known as M8 or Messier 8, is a large gas cloud within the Milky Way Galaxy, barely visible to the human eye under good conditions. It appears a few degrees above and to the right of the Teapot asterism in the constellation Sagittarius. Visually about three times the size of the full moon, the Lagoon Nebula is the largest and brightest of a number of nebulosities in and around Sagittarius. Follow the links inside to learn more.

Milky Way over Utah, and a moonlit blue hour

Mike Taylor captured this photo, and he wrote:

The Milky Way rises above the desert dunes at Goblin Valley State Park near Green River, Utah while the setting crescent moon lights up the foreground and creates a ‘blue hour’ glow in the sky.

Orion the Hunter and Sirius the Dog Star

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The first hints of the changing of the seasons can be seen in the predawn and dawn sky: Orion the Hunter and Sirius the Dog Star. The very noticeable constellation Orion the Hunter rises before dawn at this time of year, and Sirius follows the Hunter into the sky at or close to dawn. Orion will become visible in the evening by winter, but presently the Hunter lords over the southeastern sky at dawn’s first light.

Pluto-bound New Horizons crosses Neptune’s orbit

Neptune and Triton, as captured by the New Horizons spacecraft on July 10, 2014, about one year before its planned 2015 Pluto encounter.  New Horizons crosses Neptune's orbit on August 25, 2014.

Neptune and Triton, as captured by the New Horizons spacecraft on July 10, 2014, about one year before its planned 2015 Pluto encounter. New Horizons crosses Neptune’s orbit on August 25, 2014. Image via NASA / JHU / APL New Horizons spacecraft.

On August 25, 2014, the Pluto-bound New Horizons spacecraft is crossing the orbit of the 8th planet in our solar system, Neptune. NASA says this is New Horizons’ last major crossing en route to becoming the first probe to make a close encounter with distant Pluto on July 14, 2015. While traveling toward Pluto earlier this summer, New Horizons spacecraft imaged the very distant Neptune and Triton using the LORRI (LOng Range Reconnaissance Imager) camera from a distance of 3.957 billion kilometers / 2.457 billion miles. Triton is visible at the 10 o’clock position in relation to Neptune.

Five finalists for Philae landing site on Rosetta’s comet

Landing site candidate A, larger lobe of Comet.  Image via OSIRIS NAC Rosetta.

Landing site final candidate A, larger lobe of Comet 67P/Churyumov–Gerasimenko. One km square area. Image via OSIRIS NAC Rosetta.

The Rosetta mission’s Philae lander is due to set down on Comet 67P/Churyumov–Gerasimenko on November 11, 2014. Rosetta has been moving in tandem with this comet since August 6, the first spacecraft ever to rendezvous with a comet and follow it in orbit. Today (August 25, 2014), ESA named five finalists as potential sites for Philae’s spectacular comet landing. Interesting to see that the prime sites are on differing terrain. They are far more diverse than I expected. One close-up image above; the other four inside.

Back to the future with Neptune’s fascinating moon Triton

Neptune and Triton, via Voyager 2.

Neptune and Triton, via Voyager 2.

On the anniversary of Voyager 2′s encounter with Neptune and Triton … an awesome collection of restored Voyager 2 images, plus the link between Triton and Pluto.