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NASA scientists have mapped the bottom of the Greenland ice sheet in order to better predict how fast in might melt due to future climate change. Credit: NASA Two NASA satellites peering out over the Greenland ice sheet have helped researchers map areas thousands of meters beneath the thick, icy surface. The new map, created by NASA scientists, is the first of its kind and shows regions underlying the ice sheet that are likely thawed or frozen, as well as areas where the state remains unknown. This information will help scientists better predict how quickly the rest of the ice sheet will melt in the future, NASA officials said in a statement. "We're ultimately interested in understanding how the ice sheet flows and how it will behave in the future," Joe MacGregor, lead author of the new research and a glaciologist at NASA's Goddard Space Flight Center, said in the statement. "If the ice at its bottom is at the melting-point temperature, or thawed, then there could be enough liquid water there for the ice to flow faster and affect how quickly it responds to climate change." [Greenland's 'Grand Canyon' Revealed by Ice-Penetrating Radar (Video)] The bottom of the Greenland ice sheet is often tens of degrees warmer than the surface due to some geothermal heat that rises from deep inside the Earth. This heat causes some areas to thaw, while other areas remain frozen solid. This map illustrates what NASA scientists believe is happening at the base of the Greenland ice sheet. The areas marked in red represent areas that have thawed, while blue areas remain frozen solid. Insufficient data was available for a third section of the ice sheet, which is represented in grey. Credit: NASA Earth Observatory/Jesse AllenUntil now, scientists relied on only a few, isolated boreholes (dug directly into the ice sheet) to study what was going on at the bottom. The researchers of the new work, however, combined multiple methods, including observations from NASA's Terra and Aqua satellites. Using images captured by these two Earth-observing satellites, the researchers were able to look for areas of rugged terrain, which generally indicate that ice moved over the surface and carved a trail in a thawed bed at the bottom, NASA officials said in the statement. The researchers also clocked the speed of the surface ice to see if it was exceeding its "speed limit" and moving exceptionally fast. That would mean the ice was no longer frozen to the rock beneath it, which would suggest the underlying area was thawed, according to the study, published July 23 in the Journal of Geophysical Research. The team also studied the individual layers of ice using radars onboard NASA's Operation IceBridge aircraft and used computer models to predict temperatures at the bottom of the ice sheet. "Each of these methods has strengths and weaknesses. Considering just one isn't enough. By combining them, we produced the first large-scale assessment of Greenland's basal thermal state," MacGregor said. Based on the new findings, the researchers determined that the southwestern and northeastern areas (shown in red) are already thawed, while the central and western areas (shown in blue) remain frozen. However, there is still not enough data to conclude what is going on under a third section of the ice sheet, which remains grey on the map. "I call this [new study] the piñata, because it's a first assessment that is bound to get beat up by other groups as techniques improve or new data are introduced," MacGregor said in the statement. "But that still makes our effort essential, because prior to our study, we had little to pick on." Source : http://www.space.com/33664-nasa-map-reveals-thawing-under-greenland.html -
Source + more photo's : http://www.space.com/32252-amazing-images.html
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Four old red dwarf stars — Proxima Centauri, Barnard's Star, GJ3253 and G184-31— had lower-than-expected X-ray emissions, suggesting these stars and the sun generate their magnetic fields in the same way. Credit: X-ray: NASA/CXC/Keele Univ./N. Wright et al; Optical: DSS Unusual X-ray emissions coming from four old red dwarf stars suggest these old fogeys have something in common with our sun: their magnetic fields are weakening over time, new research shows. With masses less than half that of the sun, red dwarfs are the smallest of stars (the most massive stars are 100 or more times larger than the sun,according to NASA). The relatively petite stature of these stars means they burn at a much lower temperature than the sun (and are therefore much dimmer), and have very different interior structures. Red dwarfs also have a very different interior structure compared with the sun, which is why the authors of the new research were surprised to find similarities in the way the magnetic fields in these two types of stars change as they age. The sun's magnetic field plays a huge role in protecting Earth from harsh radiation from space, and the new results could help researchers decipher how that magnetic field is created. [Star Lash! White Dwarf Literally Whipping Red Dwarf (Video)] Magnetic fields in the sun and stars like it are generated by a dynamo, which is a process involving convection — the rising and falling of hot gas in the star's interior — and the rotation of the star. As stars like the sun age, their rotation slows down and the strength of their magnetic field is weakened, Nicholas Wright, lead author of the new study and an astrophysicist from Keele University in England, told Space.com. Inside the sun, a transition region called a tachocline separates the radiative core and the convective region. But smaller, low-mass stars have been shown to be fully convective, according to the new study published Thursday (July 28) in the journal Nature. The brightness of a star's X-ray emission is a good indicator of its magnetic field strength, according to a statement from NASA. Using data from NASA's Chandra X-ray Observatory, the astronomers behind the new study discovered lower-than-expected magnetic field strength from four old red dwarf stars: Proxima Centauri, Barnard's Star, GJ3253 and G184-31, Wright said. "We thought we'd find these [red dwarf] stars would have higher X-ray emissions like [faster rotating, younger red dwarf stars], but they have lower X-ray emissions and they show the same correlation between rotation rate and X-ray emissions that stars like our sun have," Wright said. "This means these two types of stars — red dwarfs and the sun — are operating very similar dynamo processes, despite different internal structures." The graph shows the correlation between X-ray emission and rotational speed. The faster the star rotates, the brighter it is. Credit: N. Wright et alThe new finding brings researchers closer to fully understanding how the magnetic field in the sun and stars like it are generated, NASA officials said in the statement. "For a long time, we thought the tacholine was really important for how stars generate their magnetic field," Wright added. "But now, there are some doubts because red dwarfs lack that tacholine." Although the red dwarfs appear to be rotating very slowly now, they were born rotating a lot faster. This means they would have had stronger magnetic fields and released a lot of flares at a younger age, which could have had an impact on nearby planets orbiting such stars, Wright said. "This could be important for life around such stars, as it will mean the conditions on planets orbiting such stars will be more peaceful than we had once thought — at least once the stars have aged a little," he added. Next, researchers hope to examine the magnetic fields of 10 other red dwarf stars, which will expand the researchers' sample size and help them confirm their findings. Source: http://www.space.com/33607-sun-like-stars-magnetic-field-generation.html
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For the first time ever, a private company has permission to land on the moon. The U.S. government has officially approved the planned 2017 robotic lunar landing of Florida-based Moon Express, which aims to fly commercial missions to Earth's nearest neighbor and help exploit its resources, company representatives announced today (Aug. 3). "This is not only a milestone, but really a threshold for the entire commercial space industry," Moon Express co-founder and CEO Bob Richards told Space.com. [Images: Moon Express' Private Lunar Lander] Previously, companies had been able to operate only on or around Earth. The new approval, while exclusive to Moon Express, could therefore serve as an important regulatory guide for deep-space commercial activity in general, Richards said. Artist's concept of Moon Express' MX-1 lunar lander on its way to the moon. Credit: Moon Express"Nobody's had a deep-sea voyage yet. We're still charting those waters," he said. "Somebody had to be first." Moon Express submitted an application to the U.S. Federal Aviation Administration (FAA) on April 8. The document then made its way through the U.S. State Department, the U.S. Department of Defense, NASA, the National Oceanic and Atmospheric Administration, and the Federal Communications Commission, Richards said. The interagency approval process "took some time, not because anybody was against or averse to this," he said. "It's just that we asked questions that had never been asked before, and that had to be addressed and worked out." Moon Express can now focus exclusively on the financial and technical challenges of the 2017 moon mission, which will begin with the launch of the company's MX-1 lander atop a Rocket Lab Electron booster. (Moon Express signed a multilaunch deal with Rocket Lab last year.) he main goal of the maiden launch is to test out the MX-1's performance and capability on the lunar surface. Moon Express representatives also hope to win the Google Lunar X-Prize, a $30 million competition to land a privately funded robotic vehicle on the moon by the end of 2017. The first team to pull off this landing — and get the vehicle to move at least 1,640 feet (500 meters) on the lunar surface, and beam high-definition video and photos back to Earth — will win the $20 million grand prize. (The second team to achieve all of this gets $5 million, and another $5 million is available for meeting other milestones. At the moment, 16 teams remain in the running.) "We're still shooting for the end of 2017," Richards said of the maiden MX-1 moon mission. "A lot has to go right, but at least we have a shot at our moon shot, given this regulatory approval." If all goes according to plan, future Moon Express missions will help assess, extract and exploit lunar resources such as water ice, helping to launch a new era in space exploration, company representatives have said. "Space travel is our only path forward to ensure our survival and create a limitless future for our children," Moon Express co-founder and Chairman Naveen Jain said in a statement today. "In the immediate future, we envision bringing precious resources, metals and moon rocks back to Earth. In 15 years, the moon will be an important part of Earth’s economy, and potentially our second home." source + video's: http://www.space.com/33632-moon-express-private-lunar-landing-approval.html
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As an Earthling, it's easy to believe that we're standing still. After all, we don't feel any movement in our surroundings. But when you look at the sky, you can see evidence that we are moving. Some of the earliest astronomers proposed that we live in a geocentric universe, which means that Earth is at the center of everything. They said the sun rotated around us, which caused sunrises and sunsets — same for the movements of the moon and the planets. But there were certain things that didn't work with this vision. Sometimes, a planet would back up in the sky before resuming its forward motion. We know now that this motion — which is called retrograde motion — happens when Earth is "catching up" with another planet in its orbit. For example, Mars orbits farther from the sun than Earth. At one point in the respective orbits of Earth and Mars, we catch up to the Red Planet and pass it by. As we pass by it, the planet moves backward in the sky. Then it moves forward again after we have passed. Another piece of evidence for the sun-centered solar system comes from looking at parallax, or apparent change in the position of the stars with respect to each other. For a simple example of parallax, hold up your index finger in front of your face at arm's length. Look at it with your left eye only, closing your right eye. Then close your right eye, and look at the finger with your left. The finger's apparent position changes. That's because your left and right eyes are looking at the finger with slightly different angles. The same thing happens on Earth when we look at stars. It takes about 365 days for us to orbit the sun. If we look at a close-up star in the summer, and look at it again in the winter, its apparent position in the sky changes because we are at different points in our orbit. We see the star from different vantage points. With a bit of simple calculation, using parallax we can also figure out the distance to that star. How fast are we spinning? Earth's spin is constant, but the speed depends on what latitude you are located at. Here's an example. The circumference (distance around the largest part of the Earth) is roughly 24,898 miles (40,070 kilometers),according to NASA. (This area is also called the equator.) If you estimate that a day is 24 hours long, you divide the circumference by the length of the day. This produces a speed at the equator of about 1,037 mph (1,670 km/h). You won't be moving quite as fast at other latitudes, however. If we move halfway up the globe to 45 degrees in latitude (either north or south), you calculate the speed by using the cosine (a trigonometric function) of the latitude. A good scientific calculator should have a cosine function available if you don't know how to calculate it. The cosine of 45 is 0.707, so the spin speed at 45 degrees is roughly 0.707 x 1037 = 733 mph (1,180 km/h). That speed decreases more as you go farther north or south. By the time you get to the North or South Poles, your spin is very slow indeed — it takes an entire day to spin in place. Space agencies love to take advantage of Earth's spin. If they're sending humans to the International Space Station, for example, the preferred location to do so is close to the equator. That's why space shuttle missions used to launch from Florida. By doing so and launching in the same direction as Earth's spin, rockets get a speed boost to help them fly into space. How fast does Earth orbit the sun? Earth's spin, of course, is not the only motion we have in space. Our orbital speed around the sun is about 67,000 mph (107,000 km/h),according to Cornell. You can calculate that with basic geometry. First, we have to figure out how far Earth travels. Earth takes about 365 days to orbit the sun. The orbit is an ellipse, but to make the math simpler, let's say it's a circle. So, Earth's orbit is the circumference of a circle. The distance from Earth to the sun — called an astronomical unit— is 92,955,807 miles (149,597,870 kilometers), according to the International Astronomers Union. That is the radius (r). The circumference of a circle is equal to 2 x π x r. So in one year, Earth travels about 584 million miles (940 million km). Since speed is equal to the distance traveled over the time taken, Earth's speed is calculated by dividing 584 million miles (940 million km) by 365.25 days and dividing that result by 24 hours to get miles per hour or km per hour. So, Earth travels about 1.6 million miles (2.6 million km) a day, or 66,627 mph (107,226 km/h). Sun and galaxy move, too To blow your mind even more: the sun has an orbit of its own in the Milky Way. The sun is about 25,000 light-years from the center of the galaxy, and the Milky Way is thought to be about 100,000 light-years across. We are thought to be about halfway out from the center, according to Stanford University. The sun and the solar system appear to be moving at 200 kilometers per second, or at an average speed of 515,000 mph (828,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way. The Milky Way, too, moves in space relative to other galaxies. In about 4 billion years, the Milky Way will collide with its nearest neighbor, theAndromeda Galaxy. The two are rushing toward each other at about 70 miles per second (112 km per second). Everything in the universe is, therefore, in motion. What would happen if Earth stopped spinning? There is no chance that you'll be flung off to space right now, because the Earth's gravity is so strong compared to its spinning motion. (This latter motion is called centripetal acceleration.) At its strongest point, which is at the equator, centripetal acceleration only counteracts Earth's gravity by about 0.3 percent. In other words, you don't even notice it, although you will weigh slightly less at the equator than at the poles. NASA says the probability for Earth stopping its spin is "practically zero" for the next few billion years, so you can feel safe in knowing you'll stay in place. Theoretically, however, if the Earth did stop moving suddenly, there would be an awful effect. The atmosphere would still be moving at the original speed of the Earth's rotation. This means that everything would be swept off of land, including people, buildings and even trees, topsoil and rocks, NASA added. What if the process was more gradual? This is the more likely scenario over billions of years, NASA said, because the sun and the moon are tugging on Earth's spin. That would give plenty of time for humans, animals and plants to get used to the change. By the laws of physics, the slowest the Earth could slow its spin would be 1 rotation every 365 days. That situation is called "sun synchronous" and would force one side of our planet to always face the sun, and the other side to permanently face away. By comparison: Earth's moon is already in an Earth-synchronous rotation where one side of the moon always faces us, and the other side opposite to us. But back to the no-spin scenario for a second: There would be some other weird effects if the Earth stopped spinning completely, NASA said. For one, the magnetic field would presumably disappear because it is thought to be generated in part by a spin. We'd lose our colorful auroras, and the Van Allen radiation belts surrounding Earth would probably disappear, too. Then Earth would be naked against the fury of the sun. Every time it sent a coronal mass ejection (charged particles) toward Earth, it would hit the surface and bathe everything in radiation. "This is a significant biohazard," NASA said. Another weird effect: most spots on Earth would have daylight for half a year, and nighttime for the other half. During the day, the surface temperature would change depending on what latitude you're at. The equator would be even hotter than it is now, because the sun's light rays shine directly on it; the poles would not have as pronounced an effect because the rays are slanted. Because there are no more sunrises and sunsets, the sun would just move up and down in the sky during the year according to the Earth's orbit and tilt. "This long-term temperature gradient would alter the atmospheric wind circulation pattern so that the air would move from the equator to the poles rather than in wind systems parallel to the equator like they are now," NASA added. source + time laps video: http://www.space.com/33527-how-fast-is-earth-moving.html
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A new American reconnaissance satellite has made it to orbit to begin the latest secret mission for the U.S. government. The classified NROL-61 satellite launched into space from Cape Canaveral Air Force Station in Florida this morning (July 28) at 8:37 a.m. EDT (1237 GMT), riding into space atop a two-stage United Launch Alliance (ULA) Atlas V rocket. NROL-61 will be operated by the National Reconnaissance Office (NRO), the agency in charge of the United States' fleet of spy satellites. NRO payloads are generally classified, and NROL-61 is no exception; no information is available about the satellite's precise activities or final orbit. (ULA's brief mission description states simply that NROL-61 will operate "in support of national defense.") You can see more launch photos from the Atlas V mission in our full image gallery here. http://www.space.com/33578-spy-satellite-nrol-61-atlasv-rocket-launch-photos.html – A United Launch Alliance (ULA) Atlas V rocket carrying the classified NROL-61 satellite lifts off from Space Launch Complex-41 at Cape Canaveral Air Force Station in Florida on July 28, 2016 on mission for the U.S. National Reconnaissance Office. Credit: United Launch Alliance/Jeff Spotts NROL-61 is the third NRO satellite to lift off this year. The NROL-45 mission launched atop a ULA Delta IV rocket in February from Vandenberg Air Force Base in California, and NROL-37 rode a Delta IV Heavy — the most powerful rocket currently in operation — to orbit from Cape Canaveral last month. The NRO chose a cartoon lizard, dubbed Spike, as the mascot for the NROL-launch, with an image of the reptile launching into space on the Atlas V. Another mission, known as NROL-79, is scheduled to launch atop an Atlas V in December, also from Cape Canaveral. The Atlas V that blasted off today was the "421" configuration, which features a payload fairing 13 feet (4 meters) wide and two solid rocket boosters (SRBs) attached to the central core booster. The rocket reached Mach 1 (the speed of sound) 47 seconds after liftoff, and the two SRBs were jettisoned at 2 minutes and 9 seconds post-launch. The first-stage engine cut off at 4 minutes and 10 seconds, when the rocket was traveling at about 12,550 mph (20,200 km/h), according to a ULA mission video. Four minutes and 16 seconds into the mission, the two rocket stages separated; the upper stage, known as Centaur, then began firing to take NROL-61 to its final orbit. At the request of the NRO, ULA representatives cut of its live video feed from the Atlas V rocket shortly after the successful launch. The NRO was established in 1961 — four years after the Soviet Union launched Sputnik 1, the first-ever artificial satellite — and worked in secret until 1992, when its existence was declassified. Source + video : http://www.space.com/33569-american-spy-satellite-nrol61-launch-success.html
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The sun fired off its strongest solar flare of 2016 during an active weekend that saw three eruptions from the star's surface. The uptick in solar activity occurred overnight on Friday and Saturday (July 22 and 23) when the sun unleashed three relatively moderate solar flares, all of which were captured on video by NASA's Solar Dynamics Observatory. While all three were somewhat minor, they are the first substantial solar events in months, NASA officials said in a statement. The first solar flare registered as an M5.0 sun storm and peaked Friday night at 10:11 p.m. EDT (0211 July 23 GMT). It was followed by a second, more-intense flare, which peaked as an M7.5-class solar storm on Saturday at 1:16 a.m. EDT (0516 GMT). A third, M5.5-class flare peaked 15 minutes later, at 1:31 a.m. EDT (0531 GMT). A closeup of the M7.6-class solar flare that erupted from the sun on July 23, 2016 as seen by NASA's Solar Dynamics Observatory. Credit: NASA The M7.5 flare was the strongest sun storm of 2016, according to Spaceweather.com, a website that tracks space-weather events. But it was still nowhere near the most powerful types of flares the sun can unleash. "These flares were classified as M-level flares. M-class flares are the category just below the most intense flares, X-class flares," NASA officials explained in their statement. "The number provides more information about its strength. An M2 is twice as intense as an M1, an M3 is three times as intense, etc." When aimed directly at Earth, the strongest X-class solar flares can potentially pose a risk to astronauts in space, and may also disrupt GPS and communications-satellite signals. "The sun is currently in a period of low activity, moving toward what's called solar minimum, when there are few to no solar eruptions. So these flares were the first large ones observed since April," NASA officials said. "They are categorized as midstrength flares, substantially less intense than the most powerful solar flares." Source + video from the event : http://www.space.com/33543-strongest-solar-flare-of-2016-video.html
