суббота, 27 августа 2016 г.

The Milky Way Sets

Under dark skies the setting of the Milky Way can be a dramatic sight. Stretching nearly parallel to the horizon, this rich, edge-on vista of our galaxy above the dusty Namibian desert stretches from bright, southern Centaurus (left) to Cepheus in the north (right). From early August, the digitally stitched, panoramic night skyscape captures the Milky Way's congeries of stars and rivers of cosmic dust, along with colors of nebulae not readily seen with the eye. Mars, Saturn, and Antares, visible even in more luminous night skies, form the the bright celestial triangle just touching the trees below the galaxy's central bulge. Of course, our own galaxy is not the only galaxy in the scene. Two other major members of our local group, the Andromeda Galaxy and the Triangulum Galaxy, lie near the right edge of the frame, beyond the arc of the setting Milky Way. via NASA http://ift.tt/2bumCEz

четверг, 25 августа 2016 г.

Curiosity at Murray Buttes on Mars

What are these unusual lumps on Mars? As NASA's robotic Curiosity rover continues rolling across Mars, it is now approaching Murray Buttes. Several of the 15-meter high buttes are visible ahead in this horizontally compressed 360-degree across image taken inside Gale Crater earlier this month. The buttes are thought similar to Earth buttes in that they are capped with dense rock that is relatively resistant to erosion. In the image center is Curiosity's "arm" and "hand" used to examine rocks up close, drill into rocks, and collect samples. Curiosity has reached its four year anniversary on Mars and has been cleared to spend the next two years further exploring the slopes of Mount Sharp, the peak of which is the distant light-colored structure visible on the far left. via NASA http://ift.tt/2bglGC5

понедельник, 22 августа 2016 г.

Map of Total Solar Eclipse Path in 2017 August

Would you like to see a total eclipse of the Sun? If so, do any friends or relatives live near the path of next summer's eclipse? If yes again, then you might want to arrange a visit for one year from today. Next year on this exact date, the path of a total solar eclipse will cut right across the center of the contiguous USA. All of North America and part of South America will experience, at the least, a partial solar eclipse. Featured here is a map of the path of totality, computed by eclipse expert Fred Espenak of NASA's GSFC. Many people who have seen a total solar eclipse tell stories about it for the rest of their lives. The last path of solar totality that included any part of the contiguous USA was in 1979, and the next two will be in 2024 and 2044. via NASA http://ift.tt/2bdhxQS

воскресенье, 21 августа 2016 г.

Gamma rays and Comet Dust

Gamma-rays and dust from periodic Comet Swift-Tuttle plowed through planet Earth's atmosphere on the night of August 11/12. Impacting at about 60 kilometers per second the grains of comet dust produced this year's remarkably active Perseid meteor shower. This composite wide-angle image of aligned shower meteors covers a 4.5 hour period on that Perseid night. In it the flashing meteor streaks can be traced back to the shower's origin on the sky. Alongside the Milky Way in the constellation Perseus, the radiant marks the direction along the perodic comet's orbit. Traveling at the speed of light, cosmic gamma-rays impacting Earth's atmosphere generated showers too, showers of high energy particles. Just as the meteor streaks point back to their origin, the even briefer flashes of light from the particles can be used to reconstruct the direction of the particle shower, to point back to the origin on the sky of the incoming gamma-ray. Unlike the meteors, the incredibly fast particle shower flashes can't be followed by eye. But both can be followed by the high speed cameras on the multi-mirrored dishes in the foreground. Of course, the dishes are MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes, an Earth-based gamma-ray observatory on the Canary Island of La Palma. via NASA http://ift.tt/2b5UZpl

суббота, 20 августа 2016 г.

Perseid Fireball at Sunset Crater

On the night of August 12, this bright Perseid meteor flashed above volcanic Sunset Crater National Monument, Arizona, USA, planet Earth. Streaking along the summer Milky Way, its initial color is likely due to the shower meteor's characteristically high speed. Entering at 60 kilometers per second, Perseid meteors are capable of exciting green emission from oxygen atoms while passing through the tenuous atmosphere at high altitudes. Also characteristic of bright meteors, this Perseid left a visibly glowing persistent train. Its evolution is seen over a three minute sequence (left to right) spanning the bottom of the frame. The camera ultimately captured a dramatic timelapse video of the twisting, drifting train. via NASA http://ift.tt/2byQIpz

четверг, 18 августа 2016 г.

Meteor before Galaxy

What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy last Friday, near the peak of the Perseid Meteor Shower, a sand-sized rock from deep space crossed right in front of our Milky Way Galaxy's far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth's atmosphere. The green color was created, at least in part, by the meteor's gas glowing as it vaporized. Although the exposure was timed to catch a Perseids meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier. via NASA http://ift.tt/2bcr8t5

среда, 17 августа 2016 г.

Five Planets and the Moon over Australia

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band. It is a coincidence, though, when several of the brightest planets all appear in nearly the same direction. Such a coincidence was captured just last week. Featured above, six planets and Earth's Moon were all imaged together last week, just before sunset, from Mornington Peninsula in Victoria, Australia. A second band is visible across the top of this tall image -- the central band of our Milky Way Galaxy. via NASA http://ift.tt/2bClNx6