Relativistic Electrons Uncovered with NASA’s Van Allen Probes

Earth’s radiation belts, two doughnut-shaped regions of charged particles encircling our planet, were discovered more than 50 years ago, but their behavior is still not completely understood. Now, new observations from NASA’s Van Allen Probes mission show that the fastest, most energetic electrons in the inner radiation belt are not present as much of the time as previously thought. The results are presented in a paper in the Journal of Geophysical Research and show that there typically isn’t as much radiation in the inner belt as previously assumed — good news for spacecraft flying in the region.

Past space missions have not been able to distinguish electrons from high-energy protons in the inner radiation belt. But by using a special instrument, the Magnetic Electron and Ion Spectrometer — MagEIS — on the Van Allen Probes, the scientists could look at the particles separately for the first time. What they found was surprising —there are usually none of these super-fast electrons, known as relativistic electrons, in the inner belt, contrary to what scientists expected.

“We’ve known for a long time that there are these really energetic protons in there, which can contaminate the measurements, but we’ve never had a good way to remove them from the measurements until now,” said Seth Claudepierre, lead author and Van Allen Probes scientist at the Aerospace Corporation in El Segundo, California.

The complete article is found here:

NuSTAR Helps Find Universe’s Brightest Pulsars

NGC 5907 ULX is the brightest pulsar ever observed. This image comprises X-ray emission data (blue/white) from ESA’s XMM-Newton space telescope and NASA’s Chandra X-ray Observatory, and optical data from the Sloan Digital Sky Survey (galaxy and foreground stars). The inset shows the X-ray pulsation of the spinning neutron star.Credit: ESA/XMM-Newton; NASA/Chandra and SDSS

There’s a new record holder for brightest pulsar ever found — and astronomers are still trying to figure out how it can shine so brightly. It’s now part of a small group of mysterious bright pulsars that are challenging astronomers to rethink how pulsars accumulate, or accrete, material.

A pulsar is a spinning, magnetized neutron star that sweeps regular pulses of radiation in two symmetrical beams across the cosmos. If aligned well enough with Earth, these beams act like a lighthouse beacon — appearing to flash on and off as the pulsar rotates. Pulsars were previously massive stars that exploded in powerful supernovae, leaving behind these small, dense stellar corpses.

The brightest pulsar, as reported in the journal Science, is called NGC 5907 ULX. In one second, it emits the same amount of energy as our sun does in three-and-a-half years. The European Space Agency’s XMM-Newton satellite found the pulsar and, independently, NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) mission also detected the signal. This pulsar is 50 million light years away, which means its light dates back to a time before humans roamed Earth. It is also the farthest known neutron star.

The complete article is here:

NASA’s MAVEN spacecraft avoids potential collision with Martian moon

NASA’s MAVEN spacecraft maneuvered Feb. 28 to avoid a “high probability” of colliding with the moon Phobos March 6. Credit: NASA – See more at: http://spacenews.com/nasa-spacecraft-avoids-potential-collision-with-martian-moon

NASA’s MAVEN spacecraft in orbit around Mars maneuvered out of the path of Phobos earlier this week after navigators predicted the spacecraft could run into the Martian moon in the near future, highlighting the challenge of tracking an international fleet of Mars probes set to double in size by 2021.

The MAVEN orbiter, in its third year studying the Martian atmosphere, performed a minor rocket burn Feb. 28 to change its speed by less than 1 mph (0.4 meters per second), NASA said, tweaking its trajectory enough to dodge a projected collision with Phobos a week later.

On its new path, MAVEN will miss the irregularly-shaped moon by around two-and-a-half minutes. The rocket burn was MAVEN’s first collision avoidance maneuver to move out of the way of Phobos, NASA said.

Phobos is located around 3,700 miles (6,000 kilometers) above Mars, higher than the altitude of NASA’s other operational orbiters — Mars Odyssey and the Mars Reconnaissance Orbiter. But MAVEN is positioned in an elliptical orbit, carrying it as high as 3,800 miles (about 6,100 kilometers) on each lap around the planet before skimming the Martian atmosphere at the orbit’s lowest point.

See the complete article here.

10 Years Strong with NASA’s THEMIS Mission

Our THEMIS mission just marked its 10th anniversary in space, discovering how mass and energy move through the near-Earth environment to determine how auroras form. The mission is still making new discoveries.

The magical night lights of the aurora are known to be caused by a space weather phenomenon known as a substorm. But prior to THEMIS, no one understood what triggered these substorms. Thanks to the mission, scientists now understand how the constant outpouring of solar material, called the solar wind, tangles Earth’s magnetic field, initiating the substorms that cause auroras. Scientists also understand the mysteries of why there are different type of auroras – like diffuse and pulsating auroras – much better now.

Learn More Here.

THEMIS by the numbers (infographic)• 5 – Number of spacecraft (two now part of ARTEMIS mission)• 2 – Number of orbits (one around Earth, one near the moon)• 25 – Number of scientific instruments aboard• 20 – Number of ground-based observatories working with THEMIS• 37 watts – Average amount of power each spacecraft needs• 282 pounds – Weight of each spacecraft• 365 GB Data – Average amount collected annually and made publicly available
Credits: NASA

GRIPS Balloon Recovered in Antarctica

The recovery of the GRIPS Balloon Gondola was staged from Amundsen-Scott South Pole Station and took place over a series of day trips out to the gondola landing site. We were able to recover all the high priority science and electronic components, although bad weather and a fuel crisis at the Pole prevented us from being able to recover the main gondola frame.

All of the recovered equipment is currently on its way back to the United States on the yearly resupply vessel from McMurdo Station. Hopefully we’ll see it all back in Berkeley in a couple of months!

A video of the GRIPS Balloon Launch, Flight and Recovery can be viewed,

The Complete NASA Article is here.

What will the ICON spacecraft do?

Years of development and testing will come to fruition when the ICON spacecraft launches from Kwajalein Atoll in the South Pacific this summer. The UC Berkeley Space Sciences Lab’s ICON team has made several videos describing the long path towards launch — and the hundreds of people involved in building this unique observatory that will study the boundary between our atmosphere and space. The second video describes what ICON will actually do and study while in orbit around the Earth.

What Will ICON Do?

How NASA is planning to touch the sun – Solar Probe Plus

An explosion on the sun shoots fiery plasma out into space.
NASA/Goddard/SDO

Our sun might not seem as enigmatic as more exotic, distant stars, but it’s still a marvelously mysterious miasma of incandescent plasma. And it’s certainly worthy of our scientific attention: Curiosity aside, a violent solar event could disrupt satellites and cause $2 trillion in damages for the U.S. alone. Yet, despite living in its atmosphere, we don’t understand some of its defining phenomena. For sixty years, we haven’t understood why the surface is a cozy 5,500 Celsius, while the halo called the corona—several million kilometers away from the star’s surface and 12 orders of magnitude less dense—boasts a positively sizzling 1-2 million Celsius.

To figure out why, NASA needs to fly a little closer to the sun—and touch it. We know that magnetic reconnection—when magnetic field lines moving in opposite directions intertwine and snap like rubber bands—propels nuclear weapon-like waves of energy away from surface. Meanwhile, magnetohydrodynamic waves—vibrating guitar string-like waves of magnetic force driven by the flow of plasma—transfer energy from the surface into corona. However, without more data, our understanding of phenomena like coronal heating and solar wind acceleration remain largely theoretical…but not for long.

A look behind the scenes of NASA’s advanced solar probe by Ian Graber-Stiehl, care of Popular Science is here.