Website Maintenence - 12/29/16

We are conducting planned maintenance on the SDO website. There may be outages or interrupted service. We apologize in advance for any inconvenience this may cause and appreciate your patience.

Planned Activities for January 2017

Another New Year is upon us and it is time to plan the next set of SDO calibration maneuvers. This includes the leap second that needs to be applied just before January starts. Why do we care about leap seconds? SDO moves about 3 km each second (about 1.9 miles every second). So does every other object in orbit near SDO. We all have to use the same time to make sure our collision avoidance programs are accurate. So we all add a leap second to the end of 2016, delaying 2017 by one second. 

Our schedule of maneuvers is:

12/31/16:  Apply Leap Second at 235959 UTC

01/04/17:  Momentum management (Delta-H) Maneuver #28, 1950 UTC (2:50 PM ET)

01/11/17:  EVE FOV (1315 UTC) and HMI/AIA Flatfield (1630 UTC) Maneuvers

01/18/17:  EVE Cruciform, 1700 UTC (12:00 noon ET)

01/25/17:  HMI Roll Maneuver, starts 1500 UTC (10:00 am ET)

02/01/17:  AIA GT/PZT Calibration, 1500 UTC (10:00 am ET)

Lunar Transit of October 30, 2016

Looks like the Moon moved across the Sun again yesterday. Not a double eclipse, but a nice example of how the Moon's orbit brings it into SDO's field of view a couple of times each year. Here is the 48-hour movie showing the lunar transit in AIA 304 (a good Halloween choice!)

The Next Two Weeks in SDO History

Today starting at 1700 UTC (1:00 pm ET) SDO will perform the EVE Cruciform calibration maneuver.

Next week, on October 26, 2016, SDO will perform the EVE Field of View calibration maneuver at 1315 UTC (9:15 am ET) and the HMI/AIA Flatfield calibration maneuver at 1630 UTC (2:30 pm ET).

During calibration maneuvers SDO science data may be unavailable, blurry, or otherwise not usable. On the other hand, the images can be fun to look at! At left is an AIA 304 image showing how SDO is tipped up a little during the first leg of the cruciform.

On October 30, 3016, SDO will experience a Lunar Transit between 1956 and 2056 UTC (3:56 and 4:56 pm ET). The Moon will cover about 59% of the Sun at the peak of this transit.

A Beautiful Joint Solar Eclipse!

Today's Joint Solar Eclipse looked beautiful from SDO. Here's a short movie in AIA 193 to show you what it looked like. It starts with the Earth between SDO and the Sun. As the Earth moves out of the way, you can see the disk of the Moon covering part of the Sun. The wobbling of the Sun is due to SDO turning off the fine-guidance system during the Earth eclipse.

Meanwhile, solar physicist Ryan Milligan was traveling in Tanzania and saw the eclipse from the ground. Here is a lovely picture of an annular eclipse — not quite total, but better than partial. This picture is a excellent example of a "Ring of Fire". The different views of the Sun, SDO seeing a partial eclipse of the Sun by the Moon while parts of Africa saw an annular eclipse, come from SDO's position to the East of Africa, a little North, and far out in space.

Thanks to Ryan for letting me show his post. You can see more of his eclipse pictures at https://twitter.com/ryanomilligan.

Momentum Management Maneuver #27 Today, Joint Solar Eclipse Tomorrow

Today at 1857 UTC (2:57 p.m. ET) SDO will do MM #27. Science mode will stop at 1847 UTC and resume at 1917 UTC (3:17 p.m. ET). Science data may be blurry or absent during that time.

Tomorrow morning between 0715 and 0731 UTC (3:15-3:31 a.m. ET), SDO will see a lunar transit as SDO exits an Earth eclipse. Parts of Africa will observe an annular solar eclipse at the same time. While these double eclipses were rare early in the SDO mission, two have happened in the last year. The SDO flight dynamics team cannot yet tell whether we will see another one next year. Even though the Sun and Moon loom large in our images, they are actually quite small and SDO's view may have the Moon outside of the Sun next September.
Enjoy the 2016 SDO Joint Solar Eclipse!

Station Keeping Maneuver Today and the Next Lunar Transit

Today from 2240-2305 UTC (6:40-7:05 p.m. ET) SDO will execute a station-keeping maneuver that keeps us within our assigned longitude box. The instruments may return data during this time, but it could be blurry.

Looking forward to September we have another lunar transit on September 1, 2016 from 0715-0731 UTC (3:15-3:31 a.m. ET). This transit will start while SDO is in the shadow of the Earth. That means when we see the Earth move out of the way the Moon will be covering part of the Sun. While these double transits did not happen the first 5 years of the mission, we may see a couple more as the Moon's orbit slowly shifts.
Here is a movie from the flight operations team showing the double transit.

On August 31, 2016, SDO will perform the EVE field of view and HMI/AIA Flatfield Maneuvers. More on that later.