This post is part of a series related to the Sun Earth Day 2011 NASA Tweetup at Goddard Space Flight Center on March 19th, 2011
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Yup! That's the Sun for you, zapping satellites, blowing hundreds of tons of the Earth's atmosphere into space, and on occasion displaying, a dazzling light show called aurora, in the upper atmosphere around the poles. To be more specific it's really an eruption from the Sun, called a Coronal Mass Ejection or CME, that causes these things.
OK, that's nice, you say, but so what? Why do I care about what the Sun is doing? Well, let me ask you these questions first. Do you like your TV, internet, cell phone, GPS, weather forecast, and your electricity? What about in-flight safety? Do you care about the massive investment made in the ISS or for the safety of astronauts living and working there? If you answered YES to any of these, then you NEED to care about the Sun, it's activity, and these Coronal Mass Ejections.
When a CME erupts it bombards the planet, our atmosphere, and the magnetosphere with a massive burst of solar wind made up of billions of tons of charged particles. Now, you're probably thinking what is nut writing about? Is he trying to scare me with this talk of bombarding the Earth with particles (electromagnetic radiation!), question whether flying is safe, and what's this about blowing the air off the planet into space? Really! Well, all of these things are true. But fortunately for us, the Earth is very well suited to handle these CME's and we are very much protected (the exceptions are satellites and the power grid which do have some vulnerabilities). This has been happening for billions of years and will continue for billions more. But, (yes there is always a but) we do need to better understand these Coronal Mass Ejections. We know these bursts of energy are slamming into us at a millions miles per hour and can affect electronics (think fried satellites), our power grid (think blackouts), and humans at high altitudes (think airplanes and astronauts). Since a CME can cause disruptions to power transmissions, do serious damage to electronics, or potentially impact your health, we really should understand when they happen, why they happen, and what can we do to better protect from the potential damage they can cause.
Thankfully the gang at NASA, scientific institutions, and universities around the globe are on the job. There are many active missions, observations being made, and models are being built to help answer the questions above.
NASA's STEREO is one such project. What does a NASA radio have to do with the Sun you ask? Nothing, STEREO is not a radio, it's an acronym for the twin (nearly identical) spacecraft launched from Cape Canaveral Air Force Station near Kennedy Space Center on October 25th, 2006 aboard a Boeing (it wasn't until December 2006 that Boeing and Lockheed formed the United Launch Alliance JV) Delta II rocket.
Below this really cool video of the launch, are a few facts about these orbiting observatories that came from the Stereo website. These are followed by a summary of Coronal Mass Ejections (CME's), a couple of links to two other significant solar missions, and a brief introduction to the IMAX film "3D Sun", or as I like to call it, the story of STEREO.
Link to the full site: STEREO Mission - Goddard Space Flight Center
The launch!
Video courtesy of NASA Kennedy YouTube Channel
The Mission:
STEREO is an acronym for Solar Terrestrial Relations Observetory. The mission is made up of two spacecraft placed on opposites sides of the Earth in order to capture stereoscoptic measuremnts of the Sun. STEREO will be capturing Coronal Mass Ejections (CME's) in stunning 3D.
The Spacecraft and Science Instruments:
1) Picture of the spacecraft with the instruments labeled.
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| Credit: JPL |
2) The two observatories are stacked for launch getting placed on a spin table to check balance & alignment.
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| Credit: NASA/George Shelton |
3) The spacecraft are loaded into the fairing on top of the launch vehicle in preparation for launch from CCAFS Space Launch Complex (SLC-17) Pad B.
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| Credit: NASA/George Shelton |
4) The Delta II stack with the twin STEREO spacecraft tucked safely inside the fairing for launch.
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| Credit: NASA/Kim Shiflett |
What are Coronal Mass Ejections?
According to the STEREO Mission and NASA websites: "CMEs are large clouds of charged particles that are ejected from the Sun over the course of several hours. These are powerful eruptions can blow up to 10 billion tons of the Sun's atmosphere into interplanetary space. They travel away from the Sun at speeds of approximately one million mph."
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Image Description: When a Coronal Mass Ejection erupted (Jan. 13, 2011), it also triggered a wave of compressed plasma across a wide portion of the lowest reaches of the Sun's outer atmosphere, the corona. As seen in extreme UV light, after repeated bursts within the bright [white] magnetic active region, the compression wave races outward, leaving a dark area behind it. This outward propagating wave of compression, like a blast on an air horn, can travel across almost the entire surface of the Sun. To generate enough force to travel such distances of hundreds of thousands of miles across the surface of the Sun suggests the enormous magnetic energy release that triggers such a storm in the first place. Credit: NASA |
This is a pretty brief explanation on CME's. I strongly encourage you to check out these links for more detail information and explanation:
Other NASA missions are studying the Sun:
There are many missions being run by NASA centers and I encourage you to go to NASA.gov and search on Missions. But here are two Sun related missions being run out of Goddard Space Flight Center that I want to highlight:
- SOHO - Solar & Heliospheric Obseratory: "SOHO cooperative effort between ESA and NASA. SOHO was designed to study the internal structure of the Sun, it's extensive outer atmosphere, and the origin of the solar wind."
- SDO - Solar Dynamics Observatory: "SDO will help us understand where the Sun's energy comes from, how the inside of the Sun works, and how energy is stored and released into the Sun's atmosphere."
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| Credit: NASA/SDO AIA 171 taken 2011-03-25 19:45:01 UT |
What about this "3D Sun" IMAX movie anyway? What's that all about?
As you know from my other posts (and if you don't, check them out after this) our Sun Earth Day tweetup started at the Smithsonian National Air and Space Museum. We climbed onto two WiFi enabled buses and headed to DC. We were quickly ushered into the Lockheed IMAX theater for a special showing for "3D Sun" which was a privilege since it is not currently being shown there. Guess what it's about? Yup, the STEREO mission! This was a fantastic 3D movie explaining the mission and bringing massive Coronal Mass Ejections into the theater in all their 3D glory. This was a great way to demonstrate the power and awesomeness of what we were about to learn during this tweetup. I would recommend this movie to you all but according to the IMAX website it is not playing anywhere at this time. Here is the 3D Sun website, maybe you can contact them for more information on possible showings. Or ask your local IMAX theater if there is a way to bring it back.
So, that's all I have for this time. Please be sure to check the links in this post, take a look at some of my past posts, and most definitely come back for future posts.
Thanks reading!
- Aaron
Disclaimer: I am not a scientist nor in anyway am I considered an expert in the topics above. I get most facts from NASA websites, NASA related publications, and general internet research. I do use books from my personal collection as well as books from the local libaray. As a reader I have some of the data stored in my head. I will cite all facts as best I can. If a fact or claim is wrong, it is completely unintentional and if it is brought to my attention, I will correct it ASAP.
- Thanks, AC
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