JUL 23, 2015 01:51 PM PDT

Dartmouth Scientists Studying Potentially Harmful X-Ray Producing Particles Entering Earth's Atmosphere

You've probably heard of the Van Allen Radiation Belts. Though they may leave you wondering why anyone would name radiation belts after a so-so band from the 80's, they're actually really important. Every once in a while the Sun spews out these massive clouds of highly charged particles moving at close to the speed of light. If you ever got a full dose from one of these things, you would die from radiation poisoning. Satellites, which, by the way, provide you with most of your modern technological life: TV transmissions, phone transmissions, GPS, the internet, they can be damaged by these particles too. The particles can also lead to depletion of the ozone layer. Lucky for you, Earth has the Van Allen (not Van Halen) radiation belts, giant concentric layers of charged particles held in place by the Earth's magnetic field, that trap these particles. Well, most of them, at least. Some of them, after rattling around in the Van Allen radiation belts, make it through and enter the Earth's atmosphere. Crazy, right? A team of Dartmouth scientists led by physicist Robyn Millan, has been conducting a unique NASA funded study of this phenomenon called BARREL (short for Balloon Array for Radiation-belt Relativistic Electron Losses) for the past two years, and they've just written a paper about their findings.

NASA researchers releasing a helium balloon part of their BARREL project

How do you study something like this? Well, first, a little more about the Van Allen radiation belts: There are two of them, one orbiting at a distance of some 8,000 to 40,000 miles above the Earth, and another inner band at about 600 to 3,700 miles. NASA has a pair of satellites called the Van Allen Probe satellites which were launched in 2012. Circling the Earth in eccentric orbits around the equator at altitudes of up to 20,000 miles, about once every nine hours, they cover the entire radiation belt region. That gave Milan and her team data about the particles trapped in the Van Allen belts. To gather information about the particles that manage to migrate from the Van Allen belts into the Earth's atmosphere, they've been using a fleet of helium balloons launched from Antarctica, some rising as high as 125,000 feet into the atmosphere. Each balloon carried a sensor array that recorded the X-rays produced as the falling electrons collided with the atmosphere.



"Our paper looked at plasma waves," explains Millan. "These are like sound waves in air except that now you are in an ionized gas so the electric and magnetic fields are affected. ... What the paper shows is that we observed these waves at the location of the Van Allen probes. We saw electric and magnetic field variations that displayed a pattern, matching the variations in the X-rays we were recording in Antarctica. ... We concluded that those waves were causing the electrons to be scattered, yielding a new understanding of how the particles are getting kicked into the atmosphere. We are learning about processes that can affect our lives directly, when active in our planetary environment. These same processes are probably happening throughout the universe and, with the tools at our disposal, we can study them in detail right here."


(Sources: phys.org, NASA, Wikipedia)
About the Author
  • Andrew J. Dunlop lives and writes in a little town near Boston. He's interested in space, the Earth, and the way that humans and other species live on it.
You May Also Like
AUG 08, 2018
Space & Astronomy
AUG 08, 2018
Astronomers Say This is the Most Distant Radio Galaxy Ever Found
Our universe is a mysterious place, and that’s why astronomers are always peering into the depths of outer space in search of clues. Sometimes they f...
AUG 12, 2018
Space & Astronomy
AUG 12, 2018
NASA's Parker Solar Probe Rockets Toward the Sun
There’s been some serious hype regarding NASA’s Parker Solar Probe in recent memory, but now all that hype is now closer than it ever has been...
SEP 04, 2018
Space & Astronomy
SEP 04, 2018
Why It's So Hard to Predict the Shape of the Universe
Astronomers still have many questions about the universe. One of those being: what is the universe’s shape? It may seem like a simple question at fir...
SEP 10, 2018
Space & Astronomy
SEP 10, 2018
The James Webb Space Telescope May Help Astronomers Search for Alien Life
Despite an onslaught of delays that have thus far prevented NASA’s James Webb Space Telescope from being launched into space, the space observatory p...
OCT 23, 2018
Space & Astronomy
OCT 23, 2018
NASA Fixes Hubble's Gyroscope Issue, Tests Planned for Near Future
On October 5th, NASA’s Hubble Space Telescope experienced a troublesome gyroscope malfunction. Onboard software attempted to rectify the issue by kic...
NOV 18, 2018
Space & Astronomy
NOV 18, 2018
International Space Station Receives Fresh Supplies From Back-to-Back Rocket Launches
Both the United States and Russian space agencies share the burden of sending fresh food, fuel, and supplies to the International Space Station every few m...
Loading Comments...