Needless to say, I have not had time to hike. Between the hot weather and flies, I must admit that I have not been very motivated to get outside.
So for today's blog update, I decided to see what is new with NASA. All of the pictures included in this update have been featured by NASA as one of their photos of the day.
A team of astronomers using NASA’s Hubble Space Telescope is reporting the discovery of another moon orbiting the icy dwarf planet Pluto. The moon is estimated to be irregular in shape and 6 to 15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system. The following image shows five moons orbiting the distant, icy dwarf planet Pluto. The green circle marks the newly discovered moon, designated P5, as photographed on July 7th. P4 was uncovered in Hubble imagery in 2011.
The Pluto team is intrigued that such a small planet can have such a complex collection of satellites. The new discovery provides additional clues for unraveling how the Pluto system formed and evolved. The favored theory is that all the moons are relics of a collision between Pluto and another large Kuiper belt object billions of years ago. The new detection will help scientists navigate NASA’s New Horizons spacecraft through the Pluto system in 2015, when it makes an historic and long-awaited high-speed flyby of the distant world. Moving past the dwarf planet at a speed of 30,000 miles per hour, New Horizons could be destroyed in a collision with even a BB-shot-size piece of orbital debris.
Pluto’s largest moon, Charon, was discovered in 1978 in observations made at the United States Naval Observatory in Washington, D.C. Hubble observations in 2006 uncovered two additional small moons, Nix and Hydra.
What did you do over your winter vacation? If you were the Opportunity rover on Mars, you spent four months of it stationary and perched on the northern slope of Greeley Haven -- and tilted so that your solar panels could absorb as much sunlight as possible. During its winter stopover, the usually rolling robot undertook several science activities including snapping over 800 images of its surroundings, many of which have been combined into the following 360-degree digitally-compressed panorama and shown in exaggerated colors to highlight different surface features. Past tracks of Opportunity can be seen toward the left, while Opportunity's dust covered solar panels cross the image bottom. Just below the horizon and right of center, an interior wall of 20-kilometer Endeavour Crater can be seen. Now that the northern Martian winter is over, Opportunity is rolling again, this time straight ahead (north). The rover is set to investigate unusual light-colored soil patches as it begins again to further explore the inside of Endeavour, a crater that may hold some of the oldest features yet visited.
The next photo below is a computer-simulated image shows gas from a star that is ripped apart by tidal forces as it falls into a black hole. Some of the gas also is being ejected at high speeds into space. Using observations from telescopes in space and on the ground, astronomers gathered the most direct evidence yet for this violent process: a super massive black hole shredding a star that wandered too close. NASA's orbiting Galaxy Evolution Explorer (GALEX) and the Pan-STARRS1 telescope on the summit of Haleakala in Hawaii were used to help to identify the stellar remains.
A flare in ultraviolet and optical light revealed gas falling into the black hole as well as helium-rich gas that was expelled from the system. When the star is torn apart, some of the material falls into the black hole, while the rest is ejected at high speeds. The flare and its properties provide a signature of this scenario and give unprecedented details about the stellar victim. The galaxy where the super massive black hole ripped apart the passing star in known as PS1-10jh and is located about 2.7 billion light years from Earth. Astronomers estimate the black hole in PS1-10jh has a mass of several million suns, which is comparable to the super massive black hole in our own Milky Way galaxy.
Engraved in rock, the ancient petroglyphs shown in the photo below are abundant in the Teimareh valley, located in the Zagros Mountains of central Iran. They likely tell a tale of hunters and animals found in the middle eastern valley 6,000 years ago or more, etched by artists in a prehistoric age. In the night sky above are star trails etched by the rotation of planet Earth during the long composite exposure made with a modern digital camera. On the left, the center of the star trail arcs is Polaris, the North Star, leaving the bright, short, stubby trail. But when these petroglyphs were carved, Polaris would have made a long arc through the night. Since the Earth's rotation axis acts like a wobbling top, 6,000 years ago the Earth's axis was some 30 degrees from its current location.
Early morning dog walkers got a visual treat this past week as bright stars and planets appeared to line up. Pictured below from left to right, are the Pleiades open star cluster, Jupiter, Venus, and the "Follower" star Aldebaran, all seen before a starry background. The image was taken from the Atacama desert in western South America. The glow of the rising Sun can be seen over the eastern horizon. Jupiter and Venus will continue to dazzle pre-dawn strollers all over planet Earth for the rest of the month.
Sometimes both heaven and Earth erupt. In Iceland the volcano Hekla erupted at the same time that auroras were visible overhead. Hekla, one of the most famous volcanoes in the world, has erupted at least 20 times over the past millennium, sometimes causing great destruction. The green auroral band occurred fortuitously about 100 kilometers above the erupting lava.
The next photo shows the magnificent spiral galaxy NGC 4565 viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices. This sharp, colorful image reveals the galaxy's bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. An assortment of other background galaxies is included in the pretty field of view, with neighboring galaxy NGC 4562 at the upper left. NGC 4565 itself lies about 40 million light-years distant and spans some 100,000 light-years.
The spacecraft, Cassini, has recorded yet another amazing view. The following photo includes a bright moon, thin rings, oddly broken clouds, and warped shadows. Titan, Saturn's largest moon, appears above as a featureless tan as it is continually shrouded in thick clouds. The rings of Saturn are seen as a thin line because they are viewed nearly edge on. Details of Saturn's rings are therefore best visible in the dark ring shadows seen across the giant planet's cloud tops. Since the ring particles orbit in the same plane as Titan, they appear to skewer the foreground moon. In the upper hemisphere of Saturn, the clouds show many details, including dips in long bright bands indicating disturbances in a high altitude jet stream. Recent precise measurements of how much Titan flexes as it orbits Saturn hint that vast oceans of water might exist deep underground.
When stars form, pandemonium reigns. A particularly colorful case is the star forming region Simeis 188 which houses an unusual and bright cloud arc shown in the photo below. Visible are red glowing emission nebulae of hydrogen, blue reflection nebulae of dust, dark absorption nebulae of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt their birthplace. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left is a naked open cluster of stars. Simeis 188 is located about 4,000 light years away.
The next NASA photo of the day reminds us of the glory days of NASA. In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon in the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This sharp image was taken by Cernan as he and Schmitt roamed the valley floor. The image shows Schmitt on the left with the lunar rover at the edge of Shorty Crater, near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples, more than was returned from any of the other lunar landing sites. Now forty years later, Cernan and Schmitt are still the last to walk on the Moon. Just for interest, my father worked for a subcontractor that helped design and build the lunar rover.
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