Data Outages Have Ended

The data outages caused by snow and ice ended Monday morning when the Sun melted the last pieces of ice off of the SDO antennas.
Many thanks to the FOT members who worked to keep the antennas pointed at SDO through a holiday weekend.

Data Outages Due to Snow in Southern New Mexico

Since last night, the SDO science telemetry downlink has been severely degraded due to snow and ice in southern New Mexico. The telemetry files being delivered to the SOCs have been partial for all three instruments. Accumulations of ice and or snow have probably collected on both SDO1 and SDO2 dishes. At the moment, conditions are still poor. The data outages will stop when the severe weather ceases.

Today's Occultation of Venus and the 2016 Mercury Transit Across the Sun

Today Venus will disappear behind the Moon at varying times across the United States. It will not be visible from SDO as we do not have a lunar transit today. Please see the front page of SpaceWeather.com for details on when to watch this occultation. You will need a pair of binoculars for the best view. Just find the Moon (a little ahead of the Sun in the sky) and watch as the bright dot of Venus goes behind it at about 12:30 p.m. ET.

But that brings up occultations that SDO will see. Next year we will see a transit of Mercury across the disk of the Sun on May 9, 2016. Here is a movie of the transit (using our predicted ephemeris, but it should be fairly close.)

The 2016 Mercury transit will last 7.5 hours. Mercury will touch the edge of the Sun at 1112 UTC (7:12 a.m. ET, called first contact), move completely into the disk at 1115 UTC, cross the center of the Sun at 1457 UTC, touch the far edge of the Sun at 1839 UTC, and leave the disk at 1842 UTC (2:42 p.m. ET, fourth contact). Unlike the 2012 Venus Transit, which was only visible in Alaska and Hawai'i, this transit will be visible throughout North America. People in the USA will be able to see most, if not all, of this transit.

Mercury is smaller and further from the Earth, so, compared to the transit of Venus in 2012, it will be a smaller disk as it passes between SDO and the Sun. Due to the shorter orbital period, transits of Mercury are more common than transits of Venus.

Johannes Kepler predicted a transit of Mercury would occur in November 1631. The first observed transit of Mercury was on November 7, 1631 by Pierre Gassendi. This was the first observed planet transit and showed that Kepler's equations of planetary motion could be used to predict the positions of planets.

SDO will provide near-realtime pictures of the Mercury Transit at a dedicated webpage. More details as the time approaches.

While you are waiting, grab your binoculars and go watch Venus disappear behind the Moon!

See SDO 4k Movies and Projected over Dublin

Trinity College Dublin (Ireland) is running a campaign in Dublin called City of Physics, showing the city of Dublin the beauty of physics. For their opening nights at the end of October, they projected images from the SDO instrument onto a city centre building. A short video is available to show the reaction of people in the city is at https://www.youtube.com/watch?v=mpEj_4aanDA. Check out the undergraduate students busy talking to Dubliners about SDO.

When SDO was launched TVs were displaying 720p resolution. In the five years since we have seen TV screens at 1080p and now UltraHD (3840 pixels by 2160 pixels.) This means we can show half of the Sun in full SDO resolution on commercially available screens. As a result, NASA has released a new of 4k ultra-HD movies of SDO imagery. These are also on YouTube. But to get the full impact of the UltraHD resolution you need to download the movies from SVS website.

The SDO webpage also has a list of UltraHD movies. We are planning to start releasing daily UltraHD movies.

If only UltraHD allowed us to show the entire disk of the Sun at the native resolution of the SDO imagers! But that must await the next generation of screens.

Today is Calibration Maneuver Day!

SDO will perform two calibration maneuvers today. The EVE field of view maneuver will run from 1315-1557 UTC (9:15 am-1:57 pm ET) and HMI/AIA Flatfield will run from 1630-1907 UTC (2:30-5:07 pm ET). SDO science data will not be available from 1315-1910 UTC (9:15 am-5:10 pm ET), although the AIA near-realtime images on the SDO website will show the Sun running back and forth across the images.

Another Lunar Transit Today

SDO will see another lunar transit today from 1718 UTC (1:18 p.m. ET) until 1733 UTC (1:33 p.m. ET). Although this is a very short transit, the Moon will occult part of the fine guidance system in AIA so we will turn off the fine guidance during the transit. That means the AIA images will drift a little and the HMI Dopplergrams and magnetograms will not be created.

SDO Website is back up

The maintenance on the SDO web and data servers is complete the website is back up and running normally. Thank you.