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Dust Glints on Martian Dunes
High-flying winds on Mars lead to twin-toned dunes, seen in this Mars Reconnaissance Orbiter image released on April 9.
The HiRISE camera aboard the orbiter sees into the infrared spectrum, revealing the dual coloring of the dunes located in the Meridiani Terra region of Mars.
Rusty, light-colored dust coats the lower-lying folds of the dunes. That’s because they are left unmolested by fierce winds that flow at higher altitudes. 
Higher up on the dunes, the winds scour their surfaces, removing the dust and revealing the dark blue sands underlying the dune crests.
photo by NASA
text from Nat Geo

Dust Glints on Martian Dunes

High-flying winds on Mars lead to twin-toned dunes, seen in this Mars Reconnaissance Orbiter image released on April 9.

The HiRISE camera aboard the orbiter sees into the infrared spectrum, revealing the dual coloring of the dunes located in the Meridiani Terra region of Mars.

Rusty, light-colored dust coats the lower-lying folds of the dunes. That’s because they are left unmolested by fierce winds that flow at higher altitudes. 

Higher up on the dunes, the winds scour their surfaces, removing the dust and revealing the dark blue sands underlying the dune crests.

photo by NASA

text from Nat Geo

As dawn broke on March 27, the center of the Milky Way Galaxy stood almost directly above the European Southern Observatory’s Paranal Observatory. In the dry, clear sky of Chile’s Atacama desert, our galaxy’s dusty central bulge is flanked by Paranal’s four 8 meter Very Large Telescope units in this astronomical fisheye view. Along the top, Venus is close to the eastern horizon. The brilliant morning star shines very near a waning crescent Moon just at the edge of one of the telescope structures. Despite the bright pairing in the east, the Milky Way dominates the scene though. Cut by dust lanes and charged with clouds of stars and glowing nebulae, the center of our galaxy sprawls across the darker zenith even as the deep blue sky grows brighter and buildings still glint in moonlight…Image Credit & Copyright: Babak Tafreshi (TWAN), ESO Ultra HD ExpeditionPosted on: http://apod.nasa.gov/apod/astropix.html
text from the Planetary Landscapes facebook page 

As dawn broke on March 27, the center of the Milky Way Galaxy stood almost directly above the European Southern Observatory’s Paranal Observatory. In the dry, clear sky of Chile’s Atacama desert, our galaxy’s dusty central bulge is flanked by Paranal’s four 8 meter Very Large Telescope units in this astronomical fisheye view. Along the top, Venus is close to the eastern horizon. The brilliant morning star shines very near a waning crescent Moon just at the edge of one of the telescope structures. Despite the bright pairing in the east, the Milky Way dominates the scene though. Cut by dust lanes and charged with clouds of stars and glowing nebulae, the center of our galaxy sprawls across the darker zenith even as the deep blue sky grows brighter and buildings still glint in moonlight…

Image Credit & Copyright: Babak Tafreshi (TWAN), ESO Ultra HD Expedition

Posted on: http://apod.nasa.gov/apod/astropix.html

text from the Planetary Landscapes facebook page 

New image of the Pleiades star cluster, a group of 800 stars formed about 100 million years ago that is located 410 light-years away from Earth.Read more: http://bit.ly/1hg6nbC via space.comImage: Chuck Manges
source 

New image of the Pleiades star cluster, a group of 800 stars formed about 100 million years ago that is located 410 light-years away from Earth.

Read more: http://bit.ly/1hg6nbC via space.com

Image: Chuck Manges

source 

Pushing the Bounds of Human Performance

Grueling Demands of the Job and How to Train For Them

By Patrick J. Kiger

It was Christmas Eve 2013, and NASA astronauts Mike Hopkins and Rick Mastracchio floated in space outside the International Space Station, where they had gone on the second of two spacewalks to fix a failing pump module that was critical to the station’s cooling system.

The repair work was something that on Earth might seem fairly basic—unplugging and removing a refrigerator-sized pump module, moving a replacement into place, and then reconnecting electrical lines and hoses that pumped ammonia into the unit. But in the unforgiving environment of orbital space, astronauts must cope with the rigors of working in a pressurized suit and adjusting one’s movements to microgravity, and they must work with great care and precision, since the slightest mistake can lead to disaster.

The December spacewalks provide an example of the extraordinary physical and mental demands of being a space station astronaut, and the extensive, painstaking training and preparation that allows them to succeed in one of the most difficult professions anyone could imagine.

Only the best of the best even get a shot. Last year, more than 6,000 applicants competed for a slot in the 2013 astronaut candidate class. Ultimately, eight were deemed worthy of entering the rigorous training that qualifies an astronaut to work on the space station, which includes extensive work in flotation tanks that simulate the microgravity environment of space.

Since the first spacewalk in the mid-1960s, astronaut training has become increasingly sophisticated, according to Allison Bolinger, NASA’s lead U.S. spacewalk officer, who has trained astronauts and worked as a controller from Earth. “We’re continually improving the training,” Bolinger says. “After a mission, we have the astronauts sit down and discuss the process with us. What are the things we need to train for, and how to we improve the training? What the things we teach that they don’t need? We’ve also had the benefit of astronauts with a lot of experience, including guys who’ve done six or so spacewalks. They can tell us how things actually are when you’re up there.”

While the basic and pre-mission training builds muscle memory and familiarity with equipment, NASA leaves nothing to chance. In the case of last December’s spacewalks, Hopkins and Mastracchio spent nine days on the station devoted to preparing for the spacewalks, according to Bolinger. They conducted daily video conferences with NASA officials on the ground, in which they planned every detail of the job and virtually every movement they would make in space. They studied slides of the equipment they would be fixing and the tools they would use to do it, and rehearsed the sequence of tasks on DOUG (Dynamic Onboard Ubiquitous Graphics), a virtual-reality trainer on the station. They even practiced one of the trickier tasks, closing and disconnecting four fluid lines on the pump that are filled with pressurized ammonia, by working with a fluid-line trainer device inside the station.

But spacewalks, in a sense, are like running marathons, in that no matter how much preparation, the experience remains a grueling one. Because of the need to accomplish as much as possible in a limited time, astronauts may have to work for six hours or more without any scheduled breaks, or even anything other than drinking water to nourish them. During that time, they’re compelled to concentrate to make sure that untethered tools and parts don’t float away, and they’ve got to pay attention to a continuous stream of verbal instructions from ground controllers, who are watching a video feed from cameras mounted on the astronauts’ helmets. And while it might seem that the microgravity of space would make movement effortless, in reality astronauts continually must move slowly and methodically, and struggle against the stiffness of the pressurized spacesuits. “You’re in an inflated balloon,” Bolinger explains. “You constantly have to fight the pressure, so that even grasping the handle of a ratchet is difficult.” After spacewalks, she says, astronauts often complain most of extreme fatigue in their hands.

Spacewalks are sufficiently trying physically that controllers on Earth continuously monitor data from sensors in the astronauts’ spacesuits, which enable them to keep tabs on the astronauts’ vital signs. “Mike Hopkins has a higher metabolic rate, so and we saw his CO2 creep up, an indication that he might be working too hard,” Bolinger recalls. “We made him stop for 10 minutes, so that we could try to get his heart rate down.” Additionally, while the astronauts are working in space, they periodically glanced down to check digital displays mounted on their spacesuits, which indicated whether the equipment needed to keep them alive in space was still working. As an additional precaution, each astronaut carried a small piece of paper attached to an elastic band on his wrist, a sort of cheat-sheet that reminded them what to do in the event they saw certain warning codes on those digital displays.

Despite all those challenges, the astronauts and their handlers managed to work so efficiently that they accomplished a task in two spacewalks that had required three walks when it was last performed in 2010. According to an Associated Press account, Hopkins held the bulky pump module with both hands and guided it to the installation spot, where he slid it into place as an astronaut inside the station, Japan’s Koichi Wakata, carefully steered a robotic arm to which the pump was attached. One complication did slow the work—what Mission Control called a “mini blizzard” of frozen chunks of ammonia that leaked from one of the lines, which bounced off the equipment and possibly the astronauts’ spacesuits as well.

But in the end, the work was successful. Six hours into the spacewalk, Hopkins announced, “Houston, you’ve got yourself a new pump module.”

source 

Plumes of water vapor discovered on dwarf planet Ceres. Water is always an exciting discovery since it is necessary for life (at least as we know it). -http://sciencenews.cc/plumes-of-water-vapor-discovered-on-dwarf-planet/
from biology 101

Plumes of water vapor discovered on dwarf planet Ceres. Water is always an exciting discovery since it is necessary for life (at least as we know it). -http://sciencenews.cc/plumes-of-water-vapor-discovered-on-dwarf-planet/

from biology 101

bacteriophage virus, by Chok Bun LamFollow me on facebook, and also tumblr for more art :)

bacteriophage virus, by Chok Bun Lam

Follow me on facebook, and also tumblr for more art :)

One of the fascinating aspects of viewing Earth at night is how well the lights show the distribution of people. In this view of Egypt, we see a population almost completely concentrated along the Nile Valley, just a small percentage of the country’s land area.
The Nile River and its delta look like a brilliant, long-stemmed flower in this astronaut photograph of the southeastern Mediterranean Sea, as seen from the International Space Station. The Cairo metropolitan area forms a particularly bright base of the flower. The smaller cities and towns within the Nile Delta tend to be hard to see amidst the dense agricultural vegetation during the day. However, these settled areas and the connecting roads between them become clearly visible at night. Likewise, urbanized regions and infrastructure along the Nile River becomes apparent (see also The Great Bend of Nile, Day & Night.)
Another brightly lit region is visible along the eastern coastline of the Mediterranean—the Tel-Aviv metropolitan area in Israel (image right). To the east of Tel-Aviv lies Amman, Jordan. The two major water bodies that define the western and eastern coastlines of the Sinai Peninsula—the Gulf of Suez and the Gulf of Aqaba—are outlined by lights along their coastlines (image lower right). The city lights of Paphos, Limassol, Larnaca, and Nicosia are visible on the island of Cyprus (image top).
Scattered blue-grey clouds cover the Mediterranean Sea and the Sinai, while much of northeastern Africa is cloud-free. A thin yellow-brown band tracing the Earth’s curvature at image top is airglow, a faint band of light emission that results from the interaction of atmospheric atoms and molecules with solar radiation at approximately 100 kilometers (60 miles) altitude.
from NASA

One of the fascinating aspects of viewing Earth at night is how well the lights show the distribution of people. In this view of Egypt, we see a population almost completely concentrated along the Nile Valley, just a small percentage of the country’s land area.

The Nile River and its delta look like a brilliant, long-stemmed flower in this astronaut photograph of the southeastern Mediterranean Sea, as seen from the International Space Station. The Cairo metropolitan area forms a particularly bright base of the flower. The smaller cities and towns within the Nile Delta tend to be hard to see amidst the dense agricultural vegetation during the day. However, these settled areas and the connecting roads between them become clearly visible at night. Likewise, urbanized regions and infrastructure along the Nile River becomes apparent (see also The Great Bend of Nile, Day & Night.)

Another brightly lit region is visible along the eastern coastline of the Mediterranean—the Tel-Aviv metropolitan area in Israel (image right). To the east of Tel-Aviv lies Amman, Jordan. The two major water bodies that define the western and eastern coastlines of the Sinai Peninsula—the Gulf of Suez and the Gulf of Aqaba—are outlined by lights along their coastlines (image lower right). The city lights of Paphos, Limassol, Larnaca, and Nicosia are visible on the island of Cyprus (image top).

Scattered blue-grey clouds cover the Mediterranean Sea and the Sinai, while much of northeastern Africa is cloud-free. A thin yellow-brown band tracing the Earth’s curvature at image top is airglow, a faint band of light emission that results from the interaction of atmospheric atoms and molecules with solar radiation at approximately 100 kilometers (60 miles) altitude.

from NASA

Tags: NASA space Earth
Hidden Hole
Photograph by Stéphane Guisard, European Southern Observatory
Viewed through an amateur telescope, the Milky Way’s dusty center sweeps diagonally across the sky, draping stellar nurseries. Behind the veil lurks the supermassive black hole at the center of our galaxy.
source

Hidden Hole

Photograph by Stéphane Guisard, European Southern Observatory

Viewed through an amateur telescope, the Milky Way’s dusty center sweeps diagonally across the sky, draping stellar nurseries. Behind the veil lurks the supermassive black hole at the center of our galaxy.

source

Astronomers for the first time have peered into the heart of a supernova that exploded 343 years ago. NASA’s NuSTAR mission has produced the first map of high-energy X-ray emissions from material created in the core of the exploding star.Read more: http://bit.ly/MKip1s via UC Berkeley
through Science Alert

Astronomers for the first time have peered into the heart of a supernova that exploded 343 years ago. NASA’s NuSTAR mission has produced the first map of high-energy X-ray emissions from material created in the core of the exploding star.

Read more: http://bit.ly/MKip1s via UC Berkeley

through Science Alert

NASA’s Curiosity Mars rover reached the edge of a dune on Jan. 30 and photographed the valley on the other side, to aid assessment of whether to cross the dune.Curiosity is on a southwestward traverse of many months from an area where it found evidence of ancient conditions favorable for microbial life to its long-term science destination on the lower slopes of Mount Sharp. Based on analysis of images taken from orbit by NASA’s Mars Reconnaissance Orbiter, a location dubbed “Dingo Gap” was assessed as a possible gateway to a favorable route for the next portion of the traverse.A dune across Dingo Gap is about 3 feet (1 meter) high, tapered off at both sides of the gap between two low scarps. Curiosity reached the eastern side of the dune on Jan. 30 and returned images that the rover team is using to guide decisions about upcoming drives.Image credit: NASA
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NASA’s Curiosity Mars rover reached the edge of a dune on Jan. 30 and photographed the valley on the other side, to aid assessment of whether to cross the dune.
Curiosity is on a southwestward traverse of many months from an area where it found evidence of ancient conditions favorable for microbial life to its long-term science destination on the lower slopes of Mount Sharp. Based on analysis of images taken from orbit by NASA’s Mars Reconnaissance Orbiter, a location dubbed “Dingo Gap” was assessed as a possible gateway to a favorable route for the next portion of the traverse.
A dune across Dingo Gap is about 3 feet (1 meter) high, tapered off at both sides of the gap between two low scarps. Curiosity reached the eastern side of the dune on Jan. 30 and returned images that the rover team is using to guide decisions about upcoming drives.
Image credit: NASA

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