Scientists have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, a region of super-energetic, charged particles surrounding the globe called the Van Allen radiation belts. Scientists knew that something in space accelerated particles in the radiation belts to more than 99 percent the speed of light but they didn’t know what that something was. New results from NASA’s Van Allen Probes now show that the acceleration energy comes from within the belts themselves. Particles inside the belts are sped up by local kicks of energy, buffeting the particles to ever faster speeds, much like a perfectly timed push on a moving swing.

The discovery that the particles are accelerated by a local energy source is akin to the discovery that hurricanes grow from a local energy source, such as a region of warm ocean water. In the case of the radiation belts, the source is a region of intense electromagnetic waves, tapping energy from other particles located in the same region. Knowing the location of the acceleration will help scientists improve space weather predictions, because changes in the radiation belts can be risky for satellites near Earth. The results were published in Science magazine on July 25, 2013.

In order for scientists to understand the belts better, the Van Allen Probes were designed to fly straight through this intense area of space. When the mission launched in August 2012, it had top-level goals to understand how particles in the belts are accelerated to ultra-high energies, and how the particles can sometimes escape. By determining that this superfast acceleration comes from these local kicks of energy, as opposed to a more global process, scientists have been able to definitively answer one of those important questions for the first time.

“This is one of the most highly anticipated and exciting results from the Van Allen Probes,” said David Sibeck, Van Allen Probes project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “It goes to the heart of why we launched the mission.”

The radiation belts were discovered upon the launch of the very first successful U.S. satellites sent into space, Explorers I and III. It was quickly realized that the belts were some of the most hazardous environments a spacecraft can experience. Most satellite orbits are chosen to duck below the radiation belts or circle outside of them, and some satellites, such as GPS spacecraft, must operate between the two belts. When the belts swell due to incoming space weather, they can encompass these spacecraft, exposing them to dangerous radiation. Indeed, a significant number of permanent failures on spacecraft have been caused by radiation. With enough warning, we can protect technology from the worst consequences, but such warning can only be achieved if we truly understand the dynamics of what’s happening inside these mysterious belts.

“Until the 1990s, we thought that the Van Allen belts were pretty well-behaved and changed slowly,” said Geoff Reeves, the first author on the paper and a radiation belt scientist at Los Alamos National Laboratory in Los Alamos, N.M. “With more and more measurements, however, we realized how quickly and unpredictably the radiation belts changed. They are basically never in equilibrium, but in a constant state of change.”

Read Full Story NASA’s Van Allen Probes Discover Particle Accelerator in the Heart of Earth’s Radiation Belts | NASA.

On Thursday, July 18, 2013 the team initiated exploratory recovery tests on the spacecraft’s two failed wheels. The recovery tests are a series of steps to characterize the performance of Reaction Wheels (RW) 4 and 2, and to determine if either could be returned to operation.

The initial test began on Thursday, July 18, 2013, with RW4. In response to test commands, wheel 4 did not spin in the positive (or clockwise) direction but the wheel did spin in the negative (or counterclockwise) direction. Wheel 4 is thought to be the more seriously damaged of the two.

On Monday, July 22, 2013, the team proceeded with a test of RW2. Wheel 2 responded to test commands and spun in both directions.

Over the next two weeks, engineers will review the data from these tests and consider what steps to take next. Although both wheels have shown motion, the friction levels will be critical in future considerations. The details of the wheel friction are under analysis.

Kepler requires extremely precise pointing to detect the faint periodic dimming of distant starlight— the telltale sign of a planet transiting the face of its host star. Too much friction from the reaction wheels can cause vibration and impact the pointing precision of the telescope.

Via Kepler Mission Manager Update: Initial Recovery Tests | NASA.

P-M Heden of The World at Night took this photo from Uppsala, Sweden in Sept. 2012. This deep landscape shot required only a wide aperture and filter to boost contrast.Image: P-M Heden / Clearskies.se / The World at Night

One of the pleasures people can get out of stargazing is noticing and enjoying the various colors that stars display in dark skies.

These hues offer direct visual evidence of how stellar temperatures vary. A good many of the summer luminaries — such as brilliant Vega which this week stands nearly overhead at around midnight — are bluish-white, but we can easily find other, contrasting colors there as well.

Look at reddish Antares, which is due south at around 10 p.m. EDT, and the yellowish-white Altair, which stands high in the south at 1 a.m. EDT. Considerably removed from this summer retinue, brilliant yellow-orange Arcturus holds forth in solitary splendor about halfway up in the west-southwest as darkness falls on these balmy July evenings.

Double color

Probably the most colorful double star in the night sky can now be found about two-thirds of the way up from the eastern horizon to the point directly overhead at 10 p.m. local daylight time: Albireo in the constellation of Cygnus, the swan, also known as the Northern Cross. Albireo supposedly marks the swan’s beak, or the base of the cross.

A small telescope or even a pair of steadily held binoculars will readily split Albireo into two tiny points of light of beautiful contrasting colors: the brighter one a rich yellowish-orange, the other a deep azure blue, both placed very close together.

Astronomer Garrett P. Serviss referred to Albireo as “… unrivaled for beauty, the larger star being pale topaz and the smaller a deep sapphire.”

via Starry Night: Colors of Summer Stars Explained: Scientific American.