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NASA Launches Satellite to Study How Sun’s Atmosphere Is Energized

NASA’s Interface Region Imaging Spectrograph (IRIS) spacecraft launched Thursday at 7:27 p.m. PDT (10:27 p.m. EDT) from Vandenberg Air Force Base, Calif. The mission to study the solar atmosphere was placed in orbit by an Orbital Sciences Corporation Pegasus XL rocket.

“We are thrilled to add IRIS to the suite of NASA missions studying the sun,” said John Grunsfeld, NASA’s associate administrator for science in Washington. “IRIS will help scientists understand the mysterious and energetic interface between the surface and corona of the sun.”

IRIS is a NASA Explorer Mission to observe how solar material moves, gathers energy and heats up as it travels through a little-understood region in the sun’s lower atmosphere. This interface region between the sun’s photosphere and corona powers its dynamic million-degree atmosphere and drives the solar wind. The interface region also is where most of the sun’s ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth’s climate.

The Pegasus XL carrying IRIS was deployed from an Orbital L-1011 carrier aircraft over the Pacific Ocean at an altitude of 39,000 feet, off the central coast of California about 100 miles northwest of Vandenberg. The rocket placed IRIS into a sun-synchronous polar orbit that will allow it to make almost continuous solar observations during its two-year mission.

The L-1011 took off from Vandenberg at 6:30 p.m. PDT and flew to the drop point over the Pacific Ocean, where the aircraft released the Pegasus XL from beneath its belly. The first stage ignited five seconds later to carry IRIS into space. IRIS successfully separated from the third stage of the Pegasus rocket at 7:40 p.m. At 8:05 p.m., the IRIS team confirmed the spacecraft had successfully deployed its solar arrays, has power and has acquired the sun, indications that all systems are operating as expected.

“Congratulations to the entire team on the successful development and deployment of the IRIS mission,” said IRIS project manager Gary Kushner of the Lockheed Martin Solar and Atmospheric Laboratory in Palo Alto, Calif. “Now that IRIS is in orbit, we can begin our 30-day engineering checkout followed by a 30-day science checkout and calibration period.”

IRIS is expected to start science observations upon completion of its 60-day commissioning phase. During this phase the team will check image quality and perform calibrations and other tests to ensure a successful mission.

NASA’s Explorer Program at Goddard Space Flight Center in Greenbelt, Md., provides overall management of the IRIS mission. The principal investigator institution is Lockheed Martin Space Systems Advanced Technology Center. NASA’s Ames Research Center will perform ground commanding and flight operations and receive science data and spacecraft telemetry.

The Smithsonian Astrophysical Observatory designed the IRIS telescope. The Norwegian Space Centre and NASA’s Near Earth Network provide the ground stations using antennas at Svalbard, Norway; Fairbanks, Alaska; McMurdo, Antarctica; and Wallops Island, Va. NASA’s Launch Services Program at the agency’s Kennedy Space Center in Florida is responsible for the launch service procurement, including managing the launch and countdown. Orbital Sciences Corporation provided the L-1011 aircraft and Pegasus XL launch system.

For more information about the IRIS mission, visit: http://www.nasa.gov/iris

 

 

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Hawaiian Telescope Discovers Ten Thousandth Near-Earth Object

English: Asteroid Toutatis from Paranal

English: Asteroid Toutatis from Paranal (Photo credit: Wikipedia)

 

Timelapse of Asteroid 2004 FH's flyby (NASA/JP...

Timelapse of Asteroid 2004 FH’s flyby (NASA/JPL Public Domain) 2004 FH is the centre dot being followed by the sequence; the object that flashes by near the end is an artificial satellite. Images obtained by Stefano Sposetti, Switzerland on March 18, 2004. Animation made Raoul Behrend, Geneva Observatory, Switzerland. (Photo credit: Wikipedia)

 

 

NASA said the 10,000th near-Earth object (NEO) has been discovered using the Pan-STARRS-1 telescope in Hawaii.

 

Astronomers spotted asteroid 2013 MZ5 on the night of June 18, marking a significant milestone for the NEO search. The space agency said 90 percent of all NEOs discovered were first detected by NASA-supported surveys.

 

“But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth,” said Lindley Johnson, program executive for NASA’s Near-Earth Object Observations Program at NASA Headquarters, Washington.

 

In order to be classified as an NEO, a comet or asteroid must approach Earth at an orbital distance to within about 28 million miles. They range in size from as small as a few feet to as large as 25 miles for the largest NEO. Asteroid 2013 MZ5 is about 1,000 feet across and will never be close enough to Earth to be considered potentially hazardous.

 

“The first near-Earth object was discovered in 1898,” said Don Yeomans, long-time manager of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif. “Over the next hundred years, only about 500 had been found. But then, with the advent of NASA’s NEO Observations program in 1998, we’ve been racking them up ever since. And with new, more capable systems coming on line, we are learning even more about where the NEOs are currently in our solar system, and where they will be in the future.”

 

About 10 percent of the 10,000 NEOs discovered are larger than six-tenths of a mile, which is roughly the size that could produce global consequences if one struck Earth. However, NASA says its program has found that none of these larger NEOs currently pose an impact threat.

 

NASA said scientists predict there to be about 15,000 NEOs that are one-and-a-half football fields in size, or 480 feet. There could be more than a million NEOs that are about one-third of a football field in size. An NEO hitting Earth would need to be about 100 feet or larger in order to cause significant damage in a populated area. The space agency said less than one percent of the 100-foot-sized NEOs have been detected.

 

“These days we average three NEO discoveries a day, and each month the Minor Planet Center receives hundreds of thousands of observations on asteroids, including those in the main-belt,” said Tim Spahr, director of the Minor Planet Center. “The work done by the NASA surveys, and the other international professional and amateur astronomers, to discover and track NEOs is really remarkable.”

 

Earlier this month, NASA announced a grand challenge focused on finding all asteroid threats to human populations. This “Great Challenge” asks citizen scientists, along with industry professionals, to focus on detecting and characterizing asteroids and learn how to deal with potential threats.

 

“We will also harness public engagement, open innovation and citizen science to help solve this global problem,” said NASA Deputy Administrator Lori Garver.

 

The space agency also invited industry and potential partners to offer up some ideas on accomplishing NASA’s goals to locate, redirect and explore an asteroid.

 

 

 

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Supermoon Coming June 24th

The Moon appears to be in a nearly circular orbit around the Earth. But that word “nearly” means that there are slight variations in its motion across the heavens.

As it turns out, the distance from the Earth to the Moon varies by about 30,000 miles. This sounds like a lot, but it only represents about a 6-7 percent deviation from the average distance between the two bodies.

On Earth, the difference between when the Moon is at its closest point (perigee) and its farthest position (apogee) causes the Moon to appear slightly smaller or larger in the sky. [Note: these terms can be a little confusing, because perigee and apogee vary after each orbit, which means they change from month to month and year to year. So they really represent the nearest and farthest points in the lunar orbit over a specific period of time.]

On June 24th, the Moon will be in a nearly full moon phase as it reaches perigee, making it appear slightly larger in the night sky. On that day, the Moon will be the closest to Earth that it will be for all of 2013. Such approaches, when perigee coincides closely with a full moon, are known as supermoons. But the apparent size difference is very difficult to see; only careful measurements reveal the difference.

This particular supermoon is actually not that great. Occurrences in each of the coming years will be even better. The best one of the century won’t happen until December 6, 2052. And the Moon will not cross within 356,400 kilometers until January 1, 2257 (356,371 km), a truly rare approach!

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Mystery of X-Ray Light from Black Holes Solved

In a new study, astrophysicists from The Johns Hopkins University, NASA and the Rochester Institute of Technology conducted research that bridges the gap between theory and observation by demonstrating that gas spiraling toward a black hole inevitably results in X-ray emissions.

The paper states that as gas spirals toward a black hole through a formation called an accretion disk, it heats up to roughly 10 million degrees Celsius. The temperature in the main body of the disk is roughly 2,000 times hotter than the sun and emits low-energy or “soft” X-rays. However, observations also detect “hard” X-rays which produce up to 100 times higher energy levels.

Julian Krolik, professor of physics and astronomy in the Zanvyl Krieger School of Arts and Sciences, and his fellow scientists used a combination of supercomputer simulations and traditional hand-written calculations to uncover their findings. Supported by 40 years of theoretical progress, the team showed for the first time that high-energy light emission is not only possible, but is an inevitable outcome of gas being drawn into a black hole.

“Black holes are truly exotic, with extraordinarily high temperatures, incredibly rapid motions and gravity exhibiting the full weirdness of general relativity,” Krolik said. “But our calculations show we can understand a lot about them using only standard physics principles.”

The team’s work was recently published in the print edition of Astrophysical Journal. His collaborators on the study include Jeremy Schnittman, a research astrophysicist from the NASA Goddard Space Flight Center, and Scott Noble, an associate research scientist from the Center for Computational Relativity and Gravitation at RIT. Schnittman was lead author.

As the quality and quantity of the high-energy light observations improved over the years, evidence mounted showing that photons must be created in a hot, tenuous region called the corona. This corona, boiling violently above the comparatively cool disk, is similar to the corona surrounding the sun, which is responsible for much of the ultra-violet and X-ray luminosity seen in the solar spectrum.

While the team’s study of black holes and high-energy light confirms a widely-held belief, the role of advancing modern technology should not be overlooked. A grant from the National Science Foundation enabled the team to access Ranger, a supercomputing system at the Texas Advanced Computing Center located at the University of Texas in Austin. Ranger worked over the course of about 27 days, over 600 hours, to solve the equations.

Noble developed the computer simulation solving all of the equations governing the complex motion of inflowing gas and its associated magnetic fields near an accreting black hole. The rising temperature, density and speed of the inflowing gas dramatically amplify magnetic fields threading through the disk, which then exert additional influence on the gas.

The result is a turbulent froth orbiting the black hole at speeds approaching the speed of light. The calculations simultaneously tracked the fluid, electrical and magnetic properties of the gas while also taking into account Einstein’s theory of relativity.

“In some ways, we had to wait for technology to catch up with us,” Krolik said. “It’s the numerical simulations going on at this level of quality and resolution that make the results credible.”

The scientists are all familiar with each other as their paths have all crossed with Krolik during graduate school at Johns Hopkins. Schnittman was previously a postdoctoral fellow mentored by Krolik from 2007 to 2010 while Noble was an assistant research scientist and instructor also under Krolik from 2006 to 2009.

The work was supported by the National Science Foundation Grants AST-0507455, AST- 0908336 and AST-1028087.

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