High above Earth, two giant rings of energetic particles trapped by the planet’s magnetic field create a dynamic and harsh environment that holds many mysteries — and can affect spacecraft traveling around Earth. NASA’s Van Allen Probes act as space detectives, to help study the complex particle interactions that occur in these rings, known as the Van Allen radiation belts. Recently, the spacecraft were in just the right place, at just the right time, to catch an event caused by the fallout of a geomagnetic storm as it happened. They spotted a sudden rise in particles zooming in from the far side of the planet, improving our understanding of how particles travel in near-Earth space.
The twin Van Allen Probes orbit one behind the other, investigating clues in a way a single spacecraft never could. In this model, the trailing spacecraft saw an increase in injected oxygen particles (blue), which was unobserved by the first. The increase in particles was due to a geomagnetic storm front that moved across the path of the orbit after the first spacecraft passed.
Credits: NASA’s Goddard Space Flight Center/Mike Henderson/Joy Ng, Producer
The two twin Van Allen Probe spacecraft orbit one behind the other, investigating clues in a way a single spacecraft never could. On one typical day, as the first instrument traveled around Earth, it spotted nothing unusual, but the second, following just an hour later, observed an increase in oxygen particles speeding around Earth’s dayside — the side nearest the sun. Where did these particles come from? How had they become so energized?
Scientists scoured the clues to figure out what was happening. With the help of computer models, they deduced that the particles had originated on the night side of Earth before being energized and accelerated through interactions with Earth’s magnetic field. As the particles journeyed around Earth, the lighter hydrogen particles were lost in collisions with the atmosphere, leaving an oxygen-rich plasma. The findings were presented in a recent paper in Geophysical Review Letters.
The unique double observations of the Van Allen Probes help untangle the complex workings of Earth’s magnetic environment. Such information has provided the very first view of these harsh belts from the inside — and it helps us better protect satellites and astronauts traveling through the region
This optical image shows the Was 49 system, which consists of a large disk galaxy, Was 49a, merging with a much smaller “dwarf” galaxy Was 49b. Image credit: DCT/NRL
A supermassive black hole inside a tiny galaxy is challenging scientists’ ideas about what happens when two galaxies become one.
Was 49 is the name of a system consisting of a large disk galaxy, referred to as Was 49a, merging with a much smaller “dwarf” galaxy called Was 49b. The dwarf galaxy rotates within the larger galaxy’s disk, about 26,000 light-years from its center. Thanks to NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) mission, scientists have discovered that the dwarf galaxy is so luminous in high-energy X-rays, it must host a supermassive black hole much larger and more powerful than expected.
“This is a completely unique system and runs contrary to what we understand of galaxy mergers,” said Nathan Secrest, lead author of the study and postdoctoral fellow at the U.S. Naval Research Laboratory in Washington.
Data from NuSTAR and the Sloan Digital Sky Survey suggest that the mass of the dwarf galaxy’s black hole is huge, compared to similarly sized galaxies, at more than 2 percent of the galaxy’s own mass.
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StarDustatHome and Stall Catchers are interactive ways for folks to help scientists analyze the vast amounts of data from their home computers. The software used for the Stall Catchers game, that is part of the EyesOnALZ is based on the StarDustatHome software.
EyesOnALZ is featured as part of the Crowd and Cloud airing tonight on many PBS stations.
EyesOnALZ is in part One, and airs about 28 minutes into the program. Check your local listings for air times.
It’s all about that bass and lots of it. Deep, deep base—sound at frequencies too low for the human ear to pick-up.
It’s called infrasound, low-frequency soundwaves formed by events as diverse as ocean waves crashing together, volcanic eruptions and earthquakes to rocket launches. These soundwaves, capable of traveling around the world multiple times, have never been recorded from the stratosphere for more than a day and a half and never over the ocean. That is, not until this past year.
NASA’s 2016 Super Pressure Balloon flight from Wanaka, New Zealand, carried the Compton Spectrometer and Imager (COSI) payload, a gamma ray telescope. Tucked behind one of COSI’s solar panels was the Carolina Infrasound instrument, a three-kilogram payload resembling a small styrofoam ice chest on the outside but with a trio of InfraBSU infrasound microphones on the inside. A Boise State University team led by Associate Professor Jeff Johnson originally designed the microphones to record volcanic explosions, but the sensors have found an unexpected new use in the stratosphere.
The Compton Spectrometer and Imager (COSI) payload just prior to launch from Wanaka, New Zealand, on a NASA super pressure balloon in May 2016. The Carolina Infrasound payload hitched a ride on the mission on a pioneering study to measure infrasound from the stratosphere. Credits: NASA/Bill Rodman
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Artist’s concept of a solar storm hitting Mars and stripping ions from the upper atmosphere. Credit: NASA/GSFC
Data collected by NASA’s MAVEN spacecraft in its first two years at Mars confirm suspicions that the solar wind is blasting away the planet’s atmosphere and helped transform the world from a warmer, wetter and potentially habitable world into the barren landscape seen today, scientists said.
The robotic orbiter has been looping around Mars since September 2014, skimming just above the Martian atmosphere at the low point of its elongated orbit and searching for particles streaming away from the planet.
As Mars is bombarded by the solar wind, a stream of solar particles that flow out through the solar system at a million miles per hour, the red planet’s atmosphere is buffeted and eroded, chipping away bit by bit, according to Bruce Jakosky, MAVEN’s principal investigator at the University of Colorado, Boulder.
Researchers examining data from MAVEN’s instruments have identified multiple processes by which Mars loses parts of its atmosphere.
Discover the processes and read the complete article here:
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.
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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.
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