Monthly Archives: July 2010

astronomy, European Space Agency, solar studies

Solar Dance

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The Interactions Between the Sun and Earth

Space Weather FX -- a series about the interactions between the Sun and Earth's magnetosphere. Courtesy MIT Haystack Observatory.

Earlier this year Mark and I completed work on a series of video podcasts called Space Weather FX. It was funded by NASA through MIT’s Haystack Observatory, and is aimed at helping people understand the interactions between the solar wind and Earth’s geomagnetic system. The series is getting some serious play around the world and we’re pleased about that. It means that people are learning just what the effect of solar activity can be on our fragile planet.

An artist's conception of the four Cluster spacecraft flying in formation to study the effects of the solar wind. Courtesy ESA.

What’s just as cool is that the European Space Agency’s Cluster series of satellites — each named after a different saucy dance: Samba, Salsa, Tango, and Rumba, have been operating for a decade, giving scientists a constant stream of data that allows them to construct a virtual 3D “picture” of how the solar wind (that stream of charged particles that moves constantly out from the Sun), affects our planet and its protective magnetic shield called the magnetosphere.

Cluster’s keen observations of magnetic field interactions have revealed how the solar wind can often penetrate the magnetosphere whipping up giant magnetic whirlpools that can spread highly energetic particles (called plasma) into the upport part of our atmosphere called the ionosphere. What’s more, it has looked carefully at a strange phenomenon called “black auroras” — a sort of “anti-aurora” that sucks electrons from Earth’s ionosphere.

The action of the solar wind and its interaction with the magnetic field of our planet generates huge electrical currents that can be measured. There are also collisions of massive, strong magnetic fields during those interactions. When those collisions take place, there’s a huge release of energy. But there’s also the creation of a central region called a “null point.”  Cluster has given scientists a way to study such a null point, helping them better understand the physics of a magnetic reconnection event.  Now, everything that Cluster studies is mostly invisible to us. We can’t stare at the solar wind and see these magnetic reconnection events.  But, Cluster’s sensitive instruments can track the interactions that so fascinate solar physicists.  It’s a great leap forward for solar physics and I hope that the mission continues for another decade — probing the often violent interactions between Sun and Earth’s magnetosphere.

solar studies, sun, sunspots

Sinuous Solar Ropes

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An Active Solar Region

Sunspot 1087 as imaged by Britta Suhre, a Germany amateur observer who took this image from her backyard in Germany. Credit: Britta Suhre, via Spaceweather.com

No, this isn’t a picture of an animal fur up close and personal — it’s a fantastically detailed image of an active area on the Sun’s surface.  The image is a highly magnified view of sunspot 1087. You can see a filament winding across the surface of the sunspot region, which is many times wider than our own planet.  Observers are monitoring the solar flares emanating from this area.  Click on the image to enlarge it and you’ll be amazed at the detail.  And, this is just one tiny region of the Sun!

You might wonder how people can get such wonderful images of the sun’s active regions. Of course, they don’t do it by looking directly at the Sun — that’s a recipe for disaster if you plan on using your eyes for anything else during your lifetime.  Of course, there are those folks who think it’s okay to look at the Sun for a few seconds — but even a short glance can do damage to your retina. And, forget about looking through a telescope or binoculars — that’s an even bigger risk to your eyesight. But, if you have a special filter for your telescope, or you have eclipse viewer glasses (which allow you to look safely at the Sun), you can do some solar observations.  People like Britta Suhre use specialized filters and cameras attached to telescopes to capture these views — and really, looking at those images is the very safest way you can enjoy the gorgeousity (technical term) of the active solar regions that the Sun is presenting to us as it ramps up to its maximum active state.  Want to see more solar images, there are plenty of places to do it:

Spaceweather.com frequently posts images of the Sun. Also check out the National Solar Observatory, the STEREO Mission site, the Solar and Heliospheric Observatory Homepage, the Wilcox Solar Observatory, the Institute for Solar Physics in Sweden , the Solar Dynamics Observatory and many others that you can find by simply Googling the term “solar observatory”.  Happy hunting!

P.S.  By the way, there’s a chance for people living at high latitudes to see possible aurorae action from solar activity. Check Spaceweather.com for more details.