Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA's Van Allen Probes Reveal Zebra Stripes in Space

20.03.2014

Scientists have discovered a new, persistent structure in one of two radiation belts surrounding Earth

NASA's twin Van Allen Probes spacecraft have shown that high-energy electrons in the inner radiation belt display a persistent pattern that resembles slanted zebra stripes. Surprisingly, this structure is produced by the slow rotation of Earth, previously considered incapable of affecting the motion of radiation belt particles, which have velocities approaching the speed of light.


Two giant belts of radiation surround Earth. The inner belt is dominated by electrons and the outer one by protons.

Image Credit: NASA

Scientists had previously believed that increased solar wind activity was the primary force behind any structures in our planet's radiation belts. However, these zebra stripes were shown to be visible even during low solar wind activity, which prompted a new search for how they were generated. That quest led to the unexpected discovery that the stripes are caused by the rotation of Earth. The findings are reported in the March 20, 2014, issue of Nature.

"It is because of the unprecedented resolution of our energetic particle experiment, RBSPICE, that we now understand that the inner belt electrons are, in fact, always organized in zebra patterns," said Aleksandr Ukhorskiy, lead author of the paper at The Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Md. "Furthermore, our modeling clearly identifies Earth's rotation as the mechanism creating these patterns. It is truly humbling, as a theoretician, to see how quickly new data can change our understanding of physical properties."

Because of the tilt in Earth's magnetic field axis, the planet's rotation generates an oscillating, weak electric field that permeates through the entire inner radiation belt. To understand how that field affects the electrons, Ukhorskiy suggested imagining that the electrons are like a viscous fluid. The global oscillations slowly stretch and fold the fluid, much like taffy is stretched and folded in a candy store machine. The stretching and folding process results in the striped pattern observed across the entire inner belt, extending from above Earth's atmosphere, about 500 miles above the planet's surface up to roughly 8,000 miles.

The radiation belts are dynamic doughnut-shaped regions around our planet, extending high above the atmosphere, made up of high-energy particles, both electrons and charged particles called ions, which are trapped by Earth's magnetic field. Radiation levels across the belts are affected by solar activity that causes energy and particles to flow into near-Earth space. During active times, radiation levels can dramatically increase, which can create hazardous space weather conditions that harm orbiting spacecraft and endanger humans in space. It is the goal of the Van Allen Probes mission to understand how and why radiation levels in the belts change with time.

"The RBSPICE instrument has remarkably fine resolution and so it was able to bring into focus a phenomena that we previously didn't even know existed," said David Sibeck, the mission scientist for the Van Allen Probes at NASA's Goddard Space Flight Center in Greenbelt, Md. "Better yet, we have a great team of scientists to take advantage of these unprecedented observations: We couldn't have interpreted this data without analysis from strong theoreticians."

NASA launched the Van Allen Probes in the summer of 2012. APL built and operates the probes for NASA's Science Mission Directorate. This is the second mission in NASA's Living With a Star program, which Goddard manages. The program explores aspects of the connected sun-Earth system that directly affect life and society.

Geoff Brown / Karen C. Fox
APL / NASA's Goddard Space Flight Center, Greenbelt, Md.

Susan Hendrix | EurekAlert!
Further information:
http://www.nasa.gov

Further reports about: APL Earth Flight Greenbelt NASA Space activity atmosphere conditions electrons particles spacecraft velocities zebra

More articles from Physics and Astronomy:

nachricht Witnessing turbulent motion in the atmosphere of a distant star
23.08.2017 | Max-Planck-Institut für Radioastronomie

nachricht Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>