Spectacular Images and Video of India From the International Space Station


Pictures and footage of India taken from space show the country by night and day as seen from the International Space Station, including a spectacular lightning storm.

The images were taken by Terry Virts, the commander of the current project, Expedition 43, at the space station and tweeted from his verified account.

A one-year joint mission between space agencies in the United States, Russia and Europe, began on Mar. 11, 2015 and is in its final days. Astronauts are expected to return to Earth on Wednesday.

The six-member crew have been conducting astrophysics research, physical science investigations and technology demonstrations, but no space walks.

Two of the crew, Scott Kelly and Mikhail Korneinko, have spent the entire year in space and have undergone medical studies to help further scientific advancements on Earth. Other astronauts were rotated in at the end of Expedition 42 in December.

Check out some other Amzing Pictures of India From space taken by Terry Virts

Source: http://blogs.wsj.com

The Fastest Stars in the Universe May Approach Light Speed


Our sun orbits the Milky Way’s center at an impressive 450,000 mph. Recently, scientists have discovered stars hurtling out of our galaxy at a couple million miles per hour. Could there be stars moving even faster somewhere out there?

After doing some calculations, Harvard University astrophysicists Avi Loeb and James Guillochon realized that yes, stars could go faster. Much faster. According to their analysis, which they describe in two papers recently posted online, stars can approach light speed. The results are theoretical, so no one will know definitively if this happens until astronomers detect such stellar speedsters—which, Loeb says, will be possible using next-generation telescopes.

But it’s not just speed these astronomers are after. If these superfast stars are found, they could help astronomers understand the evolution of the universe. In particular, they give scientists another tool to measure how fast the cosmos is expanding. Moreover, Loeb says, if the conditions are right, planets could orbit the stars, tagging along for an intergalactic ride. And if those planets happen to have life, he speculates, such stars could be a way to carry life from one galaxy to another.

It all started in 2005 when a star was discovered speeding away from our galaxyfast enough to escape the gravitational grasp of the Milky Way. Over the next few years, astronomers would find several more of what became known as hypervelocity stars. Such stars were cast out by the supermassive black hole at the center of the Milky Way. When a pair of stars orbiting each other gets close to the central black hole, which weighs about four million times as much as the sun, the three objects engage in a brief gravitational dance that ejects one of the stars. The other remains in orbit around the black hole.

Loeb and Guillochon realized that if instead you had two supermassive black holes on the verge of colliding, with a star orbiting around one of the black holes, the gravitational interactions could catapult the star into intergalactic space at speeds reaching hundreds of times those of hypervelocity stars.

This appears to be the most likely scenario that would produce the fastest stars in the universe, Loeb says. After all, supermassive black holes collide more often than you might think. Nearly all galaxies have supermassive black holes at their centers, and nearly all galaxies were the product of two smaller galaxies merging. When galaxies combine, so do their central black holes.

Loeb and Guillochon calculated that merging supermassive black holes would eject stars at a wide range of speeds. Only some would reach near light speed, but many of the rest would still be plenty fast. For example, Loeb says, the observable universe could have more than a trillion stars moving at a tenth of light speed, about 67 million miles per hour.

Because a single, isolated star streaking through intergalactic space would be so faint, only powerful future telescopes like the James Webb Space Telescope , planned for launch in 2018, would be able to detect them. Even then, telescopes would likely only see the stars that have reached our galactic neighborhood. Many of the ejected stars probably would have formed near the centers of their galaxies, and would have been thrown out soon after their birth. That means that they would have been traveling for the vast majority of their lifetimes. The star’s age could therefore approximate how long the star has been traveling. Combining travel time with its measured speed, astronomers can determine the distance between the star’s home galaxy and our galactic neighborhood.

If astronomers can find stars that were kicked out of the same galaxy at different times, they can use them to measure the distance to that galaxy at different points in the past. By seeing how the distance has changed over time, astronomers can measure how fast the universe is expanding.

These superfast rogue stars could have another use as well. When supermassive black holes smash into each other, they generate ripples in space and time called gravitational waves, which reveal the intimate details of how the black holes coalesced. A space telescope called eLISA, scheduled to launch in 2028, is designed to detect gravitational waves. Because the superfast stars are produced when black holes are just about to merge, they would act as a sort of bat signal pointing eLISA to possible gravitational wave sources.

The existence of these stars would be one of the clearest signals that two supermassive black holes are on the verge of merging, says astrophysicist Enrico Ramirez-Ruiz of the University of California, Santa Cruz. Although they may be hard to detect, he adds, they will provide a completely novel tool for learning about the universe.

In about 4 billion years, our own Milky Way Galaxy will crash into the Andromeda Galaxy. The two supermassive black holes at their centers will merge, and stars could be thrown out. Our own sun is a bit too far from the galaxy’s center to get tossed, but one of the ejected stars might harbor a habitable planet. And if humans are still around, Loeb muses, they could potentially hitch a ride on that planet and travel to another galaxy. Who needs warp drive anyway?

Source : wired.com

NASA Takes Stunning Image of Florida Nighttime Coast

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The lights of Cocoa Beach trace the curved lines of Cape Canaveral and the Kennedy Space Center, an area well known to astronauts. (NASA image)

Astronauts aboard the International Space Station took this photograph of Florida in October 2014. The peninsula is highly recognizable even at night, especially when looking roughly north, as our map-trained brains expect.

Illuminated areas give a strong sense of the size of cities. The brightest continuous patch of lights is the Miami-Fort Lauderdale metropolitan area, the largest urban area in the southeastern U.S. and home to 5.6 million people.

The next largest area is the Tampa Bay region (2.8 million people) on the Gulf Coast of the peninsula. Orlando, located in the middle, has a somewhat smaller footprint (2.3 million). A nearly straight line of cities runs nearly 560 kilometers (350 miles) along the Atlantic coast from Jacksonville, Florida, to Wilmington, North Carolina.

South of Orlando, the center and southern portions of the peninsula are as dark as the Atlantic Ocean, vividly illustrating the almost population-free Everglades wetland.

The lights of Cocoa Beach trace the curved lines of Cape Canaveral and the Kennedy Space Center, an area well known to astronauts. Dim lights of the Florida Keys extend the arc of the Atlantic coast to the corner of the image. The small cluster of lights far offshore is Freeport on Grand Bahama Island (image right). The faint blue areas throughout the image are clouds lit by moonlight.

Source : spacecoastdaily