Happy 130th Birthday, Dr. Robert H. Goddard

Robert H. Goddard, the inventor of the rockets that make spaceflight possible and the namesake of the Goddard Space Flight Center, was born this day in 1882. Goddard was born in Worcester, Massachusetts and grew up reading popular science fiction. He received patents for liquid-fueled and multi-stage rockets by 1914. While working at Clark University he used ballistic pendulua to show rockets worked in a vacuum and could be used to travel through space. Further work on rockets meant moving to New Mexico where the wide open spaces were a better place for testing.
Goddard's early work was ridiculed by the press. He once responded to a reporter's question with, "Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace."
When Goddard died on August 10, 1945 he held 214 patents involving rockets and rocket propulsion.
Happy Birthday Dr. Goddard. You left the world a more interesting place.

Goddard and his extreme altitude rocket. Courtesy of NASA/MSFC.

The First of the Fall Maneuvers is Today

Today at 1830 UTC (2:30 pm ET) we will perform the HMI roll maneuver. The images are usually oriented to solar north before we see them, but sometimes we get the watch the Sun appear to spin around. It keeps the instruments in good shape and allows the scientists to study the shape of the Sun. A recent article in Science magazine describes the surprising result that came from combining SDO and other measurements of the solar shape. The Sun is slightly oblate but less so than expected and without a change over the solar cycle.
More data is needed to understand why the Sun doesn't quite behave as we think it should.

Fall 2012 Eclipse Season Ends Tomorrow

The Fall 2012 SDO eclipse season ends tomorrow. Here is a look at the penultimate eclipse in the AIA 1600 bandpass. This wavelength of light is absorbed by the Schumann-Runge continuum of molecular oxygen at an altitude of about 110 km. This creates atomic oxygen, which moves upwards and creates the thermosphere. That atomic oxygen also is ionized by solar EUV to create the ionosphere.
At this wavelength the Sun looks like a ball with a thin, lacy network, bright active regions, and dark sunspots. Many of these features are a little above the visible surface of the Sun. They are held up by the solar magnetic fields. Welcome to the chromosphere, a layer of the solar atmosphere that will be studied by the Iris satellite. The people at LMSAL who built AIA and HMI are building Iris and hope to launch it in January.

Station-Keeping Maneuver Successful!

Last night at 2250 UTC (6:50 pm ET) SDO performed another station keeping maneuver. These short firings of the thrusters keep SDO within the longitude box that defines its inclined geosynchronous orbit. The timing of the maneuver is chosen to affect as little of the science data feed as possible. This means it is often near dusk or dawn so that the velocity of SDO very nearly in the direction of the thrusters. We off-pointed only 1" (less than the size of the Sun) for this maneuver.
We are nearing the end of the Fall 2012 eclipse season on September 29. A few more partial eclipses and we will be seeing the Sun 24/7 until the Spring 2013 eclipse season!
As with any geosynchronous satellite, our ground station experiences radio interference (RFI) near the equinox when the spacecraft appears to pass close to the Sun in the sky. This is because the Sun is a source of radio noise that can overwhelm the signal we are listening to. This years RFI season has passed without loss of any data.

Website is Back, New Sun-Grazing Comet Seen Near Jupiter

The SDO website has returned to service.
A Russian observatory is announcing the discovery of the a new sun-grazing comet, this time out near Jupiter. Comet C/2012 S1 (ISON) will approach close to the Sun in November 2013, possibly as close as 0.012 AU (about 2 Rsun above the surface). It may become visible to the naked eye as well.
Comets become visible because they outgas water and other molecules, which reflect sunlight. The further from the Sun the comet becomes visible the bigger the comet usually is. Let's hope that we can get some nice data from SDO during the perihelion passage of Comet C/2012 S1 (ISON).

Power Outage of SDO Website

The SDO website will be down while a power line is run into the server room at Goddard. It should return to service later this morning.

A "Jovial" Transit of Venus

If you lived on Jupiter you would be able to see a transit of Venus tomorrow. It might look something like the one we saw in June. Here is an example in SDO AIA 171, a time-lapse still of the black disk of Venus moving across the Sun. Even though the transit can't be seen from Earth, the Hubble Space Telescope may be able to see the small decrease in sunlight reflected off Jupiter toward Earth during the transit. SDO will help by telling the scientists how the Sun's brightness changes during the transit. Given how quiet the Sun has been of late, that should be pretty easy for us to do. Jupiter is ahead of the Earth in its orbit around the Sun, so the quiet side is rotating to face Jupiter, even as a new active region rotates into the view of the Earth.
First contact is at 0456 UTC, mid-transit is 0953 UTC and 4th contact is 1451 UTC (all September 20 UTC). That means the transit at Jupiter lasts almost 10 hours (compared to about 7.5 hours for the June 2012 Venus transit at Earth).
It's all part of our search for Earth-like planets around other stars. We see a lot of planets in the Kepler data; how can we determine which ones have water and oxygen?