SDO: Learning to Live with our Sun

I am such a happy girl right now. After some 13 hours in the car, (more for some!) George, Aleya, James and I made it to Titusville, Florida. We are here for the SDOisGO TweepUp event, and we’re catching the launch of STS-130 while we’re here! So what exactly is the SDO?

SDO stands for Solar Dynamics Observatory. This is the first mission of NASA’s Living With a Star program. We may think that Earth is the most important place in the solar system, but the Sun is the real powerhouse. We who live on this tiny rock in orbit about its fiery bulk must learn to live with what is, in its own way, a variable star.

The sun goes through a cycle of high and low activity. This manifests itself in a greater number of sunspots, solar flares, and coronal mass ejections about every eleven years. Sunspots are darkened, cooler areas of the sun, but they tell a tale of force and violence underneath. They are often linked with solar flares, which are explosions in the atmosphere of the sun that occur when magnetic energy is released. In an extremely energetic event, a coronal mass ejection can hurl electrons and protons away from the sun at incredible speeds, averaging 500 miles per hour kilometers per second! If a CME or flare is directed at Earth, these can cause power failures and disrupt satellites. As we become increasingly dependent on our power grids, cell phones, GPS, and yes, even your satellite radio, better forecasting is needed to predict such events. Enter SDO.

SDO has three instruments that will send back data on the Sun simultaneously and 24 hours a day. The Atmospheric Imaging Assembly (AIA) has four telescopes, looking at a total of ten bands, or colors, with super-high definition quality. Continually imaging the Sun’s surface and atmosphere, it will allow scientists to track the evolution of surface features and flares with a time resolution as small as 0.75 seconds. The Helioseismic and Magnetic Imager (HMI) will probe deeply into the sun and map the magnetic field structure. (How? Well, that’s so cool, I’ll devote a whole post to it later this week.) My favorite instrument of the bunch is the Extreme Ultraviolet Variability Experiment (EVE). This does just what the name says, measure the variability of the output of the sun at far-UV wavelengths. Why is that so important? UV light from the sun creates and shapes the ionosphere of the Earth. The ionosphere is the outermost layer of the Earth’s atmosphere, and although it has many beneficial effects on life, it’s a pain for low frequency radio astronomers such as myself. (So, let’s just say this will get a devoted post as well.)

SDO will sit in a geosynchronous orbit above Las Cruces, New Mexico, where a dedicated radio station will be ready to gobble up the 130 Mbps of data that this mission will send back. Project scientists are calling this an “avalanche of data.” This fits in with the trend of many modern telescopes, such as the EVLA and ALMA, producing much more data than astronomers have ever dealt with before. New techniques for handling and distributing these data are always needed.

But, don’t just take it from me. Here’s an official SDO video!

Want to get involved in solar research right now? The premier site for citizen science in astronomy, Zooniverse, has a project called Solar Stormwatch. You learn how to look for and identify solar flares, and then look at some real data from previous missions and discover solar flares better than any automated image recognition software can.

Stay tuned for more updates from KSC as we begin our adventure, and join in at a local or virtual TweetUp for the launch! I’ll be blogging here and posting pictures on Flickr. George is posting his gorgeous (and silly) photos as well!

And while we’re wrapped up in all this spacey goodness, won’t you also check out the most recent Carnival of Space at Mama Joules!

SDO Spacecraft Image

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