Topic: Magnetic Field
Greenbelt, MD – New findings based on a year’s worth of observations from NASA’s Van Allen Probes have revealed that the ring current – an electrical current carried by energetic ions that encircles our planet – behaves in a much different way than previously understood.
The ring current has long been thought to wax and wane over time, but the new observations show that this is true of only some of the particles, while other particles are present consistently.
Using data gathered by the Radiation Belt Storm Probes Ion Composition Experiment, or RBSPICE, on one of the Van Allen Probes, researchers have determined that the high-energy protons in the ring current change in a completely different way from the current’s low-energy protons.
Written by Bill Steigerwald
Greenbelt, MD – A powerful combination of observations and computer simulations is giving new clues to how the moon got its mysterious “tattoos” — swirling patterns of light and dark found at over a hundred locations across the lunar surface.
“These patterns, called ‘lunar swirls,’ appear almost painted on the surface of the moon,” said John Keller of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “They are unique; we’ve only seen these features on the moon, and their origin has remained a mystery since their discovery.” Keller is project scientist for NASA’s Lunar Reconnaissance Orbiter (LRO) mission, which made the observations.
NASA’s MAVEN orbiter observes Comet Siding Spring create havoc with Mars’ Magnetic Field during flyby
Written by Elizabeth Zubritsky
Greenbelt, MD – Just weeks before the historic encounter of comet C/2013 A1 (Siding Spring) with Mars in October 2014, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft entered orbit around the Red Planet.
To protect sensitive equipment aboard MAVEN from possible harm, some instruments were turned off during the flyby; the same was done for other Mars orbiters. But a few instruments, including MAVEN’s magnetometer, remained on, conducting observations from a front-row seat during the comet’s remarkably close flyby.
Written by Sarah Frazier
Greenbelt, MD – About 600 miles from Earth’s surface is the first of two donut-shaped electron swarms, known as the Van Allen Belts, or the radiation belts. Understanding the shape and size of the belts, which can shrink and swell in response to incoming radiation from the sun, is crucial for protecting our technology in space.
The harsh radiation isn’t good for satellites’ health, so scientists wish to know just which orbits could be jeopardized in different situations.
Written by Elizabeth Landau
Pasadena, CA – NASA’s Voyager 1 spacecraft made history in 2012 by entering interstellar space, leaving the planets and the solar wind behind. But observations from the pioneering probe were puzzling with regard to the magnetic field around it, as they differed from what scientists derived from observations by other spacecraft.
A new study offers fresh insights into this mystery. Writing in the Astrophysical Journal Letters, Nathan Schwadron of the University of New Hampshire, Durham, and colleagues reanalyzed magnetic field data from Voyager 1 and found that the direction of the magnetic field has been slowly turning ever since the spacecraft crossed into interstellar space.
NASA’s Cassini spacecraft to sample Saturn’s moon Enceladus’s ocean by flying through it’s icy plume
Written by Preston Dyches
Pasadena, CA – NASA’s Cassini spacecraft will sample the ocean of Saturn’s moon Enceladus on Wednesday, October 28th, when it flies through the moon’s plume of icy spray.
Cassini launched in 1997 and entered orbit around Saturn in 2004. Since then, it has been studying the huge planet, its rings and its magnetic field. Here are some things to know about the mission’s upcoming close flyby of Enceladus:
Written by Sarah Frazier
Greenbelt, MD – Thanks to a lucky conjunction of two satellites, a ground-based array of all-sky cameras, and some spectacular aurora borealis, researchers have uncovered evidence for an unexpected role that electrons have in creating the dancing auroras. Though humans have been seeing auroras for thousands of years, we have only recently begun to understand what causes them.
In this study, published in the Journal of Geophysical Research, scientists compared ground-based videos of pulsating auroras—a certain type of aurora that appears as patches of brightness regularly flickering on and off—with satellite measurements of the numbers and energies of electrons raining down towards the surface from inside Earth’s magnetic bubble, the magnetosphere.
Written by Elizabeth Landau
Pasadena, CA – Mysterious objects called brown dwarfs are sometimes called “failed stars.” They are too small to fuse hydrogen in their cores, the way most stars do, but also too large to be classified as planets.
But a new study in the journal Nature suggests they succeed in creating powerful auroral displays, similar to the kind seen around the magnetic poles on Earth.
“This is a whole new manifestation of magnetic activity for that kind of object,” said Leon Harding, a technologist at NASA’s Jet Propulsion Laboratory, Pasadena, California, and co-author on the study.
Written by Janet Anderson
Huntsville, AL – A fast-moving pulsar appears to have punched a hole in a disk of gas around its companion star and launched a fragment of the disk outward at a speed of about 4 million miles per hour. NASA’s Chandra X-ray Observatory is tracking this cosmic clump, which appears to be picking up speed as it moves out.
The double star system PSR B1259-63/LS 2883 – or B1259 for short – contains a star about 30 times as massive as the Sun and a pulsar, an ultra-dense neutron star left behind when an even more massive star underwent a supernova explosion.
Written by Whitney Clavin
Pasadena, CA – Fast-moving magnetic waves emanating from a distant supermassive black hole undulate like a whip whose handle is being shaken by a giant hand, according to a new study using data from the National Radio Astronomy Observatory’s Very Long Baseline Array.
Scientists used this instrument to explore the galaxy/black hole system known as BL Lacertae (BL Lac) in high resolution.
“The waves are excited by a shaking motion of the jet at its base,” said David Meier, a now-retired astrophysicist from NASA’s Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena.
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