One Astronomer's Noise

This post was originally published February 11, 2010. Some links may no longer function, and others have been updated where I can find them.

Today, we could finally, honestly, say… SDO is GO!!! The Solar Dynamics Observatory launched today at 10:23am EST by an Atlas V from Kennedy Space Center.

And there’s video of it as well. I haven’t seen an embeddable version yet, but click to see this one, taken by 13-year-old Anna Herbst from California. The ripples were seen in the clouds as a result of a shockwave just after the craft went supersonic and as it hit “max-Q” or the point at which the pressure on the craft is at its maximum. (I didn’t keep track of the timing, but Nancy Atkinson of Universe Today did!)

Such a shockwave occurs when an object is moving through a medium faster than the speed of sound in that medium (the atmosphere, in this case). The speed of sound sets the limit of how fast information about the gas can travel within that gas in the atmosphere. Sharp discontinuities in temperature, pressure, and density can occur. We could “see” these discontinuities as it reached the cirrus clouds. For whatever reason, it appeared to bust up the cloud material that was creating the sundog.

Little SDO put on quite a show in its first few minutes as a spacecraft! I’ll be writing more on SDO science and our amazing TweetUp adventure, once I get some darn sleep…