Category Archives: aurora borealis

aurora borealis, solar flares, solar physics, space weather, space weather FX

Surviving the Radiation Belts

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Understanding the Sun-Earth Connection

A Solar Dynamics Observatory (SDO) view of a dark prominence crossing beneath a coronal loop on the active surface of the Sun. This is part of a sequence of events that took place August 26-28th. Prominences are long strands of cooler gases that float above the solar surface. The loops are seen in extreme ultraviolet light by SDO. These are magnetic field lines being traced by spiraling particles above active regions of the Sun. Courtesy SDO.

Solar activity has been in the news a lot the past few months. So, unless you’ve been hiding under a rock with a tinfoil hat wrapped around your head, you’ve probably noticed numerous stories about solar flares and coronal mass ejections (CMEs) from the Sun and how they can cause everything from northern lights to power grid failures if they happen to send blasts of energized particles directly at Earth and our magnetic field.

Well, all that’s true.  And, the chances of solar activity affecting us and our technology are pretty high when the Sun is more active, as it is right now.  To be more precise, the Sun is going through a period called solar maximum, where it is more active.  Thus, we see more flares and mass ejections than during periods when the Sun is more quiescent.

This solar activity affects something called “space weather”, which refers to conditions and processes that occur in space that have the potential to affect Earth and its atmosphere.  Solar activity such as coronal mass ejections, solar flares, and the constant action of solar wind bring energy and particles from the Sun across space to Earth. Once they get here, they can disrupt Earth’s magnetic field, and they can cause radiation damage to spacecraft, and interrupt telecommunications, and affect global positioning satellite systems.  On the ground, disruptions to our magnetic field can interrupt power grids.

So, it makes sense that NASA and other space agencies are interested in studying the Sun’s influence on Earth’s radiation belts.  They’d like to be able to predict and understand solar outbursts, with an eye toward protecting us and our technology. And so, they are focusing some special attention on the near-Earth radiation environment.

You may have heard of the Van Allen belts. They were discovered and characterized in 1958 by James Van Allen, and surround our planet in a set of two torus-shaped nested belts that ranges from a thousand to 60,000 kilometers above Earth’s surface. Most of the particles that zip around in the Van Allen Belts come from the Sun, carried there by the solar wind.

Now, the interesting thing about the Van Allen Belts is that it is pretty dangerous to fly spacecraft through this region because of the intense radiation environment they contain. Anything that we want to send up to space either has to cross the belt quickly or stays pretty well away from it.  So, there haven’t been many spacecraft sent specifically to hang around IN the belt and study it for any length of time. One of the reasons is that a probe designed to spend time in the belt would need to have much of its electronics package shielded from the heavy radiation in the belt.

Two identical Radiation Storm Belt Probes will pass through the inner and outer radiation belts that surround our planet. Courtesy JHU/APL/NASA.

All that’s changing with the launch last week of the NASA Radiation Belt Storm Probes (RBSP).  These two heavily-shielded spacecraft will study the Van Allen Belts to figure out how particles get INTO the belts, what happens to them when they’re there, and where they go when they leave the belts.  The probes will also give solar physicists some insight into how such events as coronal mass ejections and solar flares affect the Van Allen Belts.

I think it’s pretty cool that we have a pair of spacecraft that are deliberately and carefully designed to survive in the Van Allen Radiation Belts for at least two years and possibly four years (when the mission is extended) in constant contact with high-energy particles.  They’lll give scientists the most in-depth look at just what’s happening in these dangerous radiation environments.

The Millstone Hill Radar installation at MIT's Haystack Observatory is part of the ground-based component of the RBSP mission. Courtesy MIT/Haystack Observatory.

What I also find interesting about this mission is that the  probes aren’t acting alone.  There is a very important ground-based portion of the RBSP mission that involves my friends over at MIT’s Haystack Observatory.

In about 60 days, when the spacecraft have gone through their commissioning period (that is, when they are tested and calibrated), then the prime science mission begins. At that time, the Millstone Hill installation at Haystack will make collaborative electric field measurements on the same magnetic field line that the RBSP is experiencing during its orbit through the inner and outer belts.  This will give scientists more than one point of view on activity in the radiation belts and help them understand the activities occurring in the belts in response to activity on the Sun.

The current solar maximum is, I think, one of THE most studied maximums in recent history.  Not only do we have spacecraft such as the RBSP probes, the Solar Dynamics Observatory, the Solar Heliospheric Observatory, STEREO and many other missions focused on the Sun and its activity, but places like Haystack Observatory are uniquely positioned to give the ground-based, almost “3-dimensional” view of what’s happening as the Sun sends its fury our way.

If you want to learn more about space weather, the RBSP mission, and others, here are a few links to help you out.  And, by all means, check it all out.  Living with a star like the Sun gives us a great chance to understand other stars and their environments, too.

Space Weather FX podcast series, MIT Haystack Observatory/Loch Ness Productions

MIT Haystack Observatory Atmospheric Physics page

Radiation Belt Storm Probes, NASA Mission to study solar effects on Earth’s radiation belts

Solar Dynamics Observatory, a NASA/JHU mission to study the Sun

STEREO, a twin-probe NASA mission to study the Sun in stereo

SOHO (Solar Heliospheric Observatory), a NASA mission to study the Sun

 

 

aurora borealis, solar flares, space weather, space weather FX, sun, sunspots

Solar Storm!

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What You Should Know

The March 7th CME. Courtesy SOHO.

I see that “big” media has picked up on the idea of solar storms, in the wake of two most recent and very strong X-class events on the Sun. The headlines are breathless and I’ve already spotted some science bloopers on some sites that should know better (sites that used to have good science reporters, but who let them go in order to concentrate on important things, like Snooki’s baby).

Anyway, for all news about solar activity, I first turn to Spaceweather.com. The folks there have noted the impact of the coronal mass ejection was light at first, but warn it could pick up in the coming hours. Thus, people who live at high latitudes — northern regions around 50 degrees north or more — should get to see even MORE auroral displays than usual. If the storms get strong enough, those of us at lower latitudes might get to glimpse some aurorae, too.

All this solar activity is actually pretty much on schedule for the Sun. It goes through cycles of high and low activity, and we’re headed into a time of very high activity called “solar maximum”.  So, increased numbers of flares and coronal mass ejections and sunspots are part of this process.  It’s perfectly normal and nothing to get worried about. But, there will be the big media reports, and there will be some fascinating whack jobs tying this to something mysterious and paranormal.

Check out MIT Haystack Observatory's Space Weather FX vodcasts at the link below!

That, too, is perfectly normal and nothing to get excited about.

Space weather, which is a term that covers all the solar-caused and geomagnetic disturbances that occur in near-Earth space, does have its down sides.  While we gaze at lovely aurorae, giant disturbances in Earth’s uppermost atmospheric layers and nearby space can disrupt power grids, satellite communications, GPS signals, and many other bits of our modern technology. So, that IS of concern,  and during such events you will read reports that warns of GPS outages or communications outages due to space weather (solar storms). This happens because these bits of technology rely on radio signals which bounce off the layers of our atmosphere in order to propagate (travel) long distances on our planet. In the case of GPS, those signals go THROUGH the atmosphere.  So, if the upper atmosphere is disturbed by space weather, those signals can get broken up, delayed, or even lost. It’s an interesting and potentially dangerous side-effect of living near a star.

A while back we worked with MIT’s Haystack Observatory on a series of short videos about space weather. The series is called Space Weather FX. You can watch the whole series here and learn more about the effects that the Sun has on us and our technology.  Also keep an eye on Spaceweather.com for the latest and most accurate info on solar activity.