Wednesday, August 20, 2014
“Certain wavelengths either do not make it through Earth’s atmosphere or cannot be seen by our eyes, so we cannot use normal optical telescopes to look at the spectrum,” said Dean Pesnell, the project scientist for the Solar Dynamics Observatory, or SDO, at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
read the rest of the article here...
We are looking forward to eclipse season starting August 29, 2014, giving us another opportunity to see the Earth's limb against the Sun. Eclipse season ends September 21, just in time for a lunar transit on September 24 from 0650-0720 UTC (2:50-3:20 a.m. ET).A station-keeping maneuver will happen on September 3, 2014, at 2245 UTC (6:45 p.pm. ET).
Saturday, July 19, 2014
This week we have the EVE cruciform maneuver on Wednesday, July 23. On Saturday, July 26 we will have a lunar transit. Here is a short movie showing how the Moon moves through the SDO field of view. The transit lasts from 1457–1542 UTC (10:57-11:42 a.m. ET).
The Sun had a spotless day on July 17! According to the SIDC there were no sunspots on the Sun that day. The average sunspot number for 2014 remains at 90, even though the daily value has been as high as 150. This was the first spotless day since 2011. Unlike the spotless days in 2009-2011, several small sunspots appeared that day. They weren't seen at the earlier time used by the official observer. Here is an HMI with the sunspot circled.
Thursday, July 10, 2014
A magnetic field is one of the fields used to track forces. It gives us a recipe to describe magnetic forces around the source of the field.
Gravitational fields are used to describe the orbits of planets around the Sun. Electric fields describe how currents flow in the power grid and how radios work. A magnetic field is how we keep track of the magnetic force created by many moving particles (or electrical currents). There are two nuclear fields as well. Fields are not simple concepts. They do not follow our usual experiences. A concept like Newton’s law of motion, that force is equal to mass times acceleration, can be seen every day. But even though they are invisible, fields are as real as the forces they allow us to calculate.
Magnetic fields come from electrical currents, whether in the Sun or a magnet. The strength of magnetic forces can be greater than the force of gravity (that’s why magnets work) but it is weaker than the electric forces between charges. It also works when the source of the magnetic field is electrically neutral!
What is a magnetic field? A magnetic field is the region of space near a body where magnetic forces due to the body can be detected. It’s the reaction of the particles that counts, not the region.
Edited 08/05/2014 to fix the bar magnet picture.
Thursday, June 12, 2014
@NASA_SDO was one of the first Twitter feeds providing updates about a NASA mission. It was where the first NASA TweetUp for launch was posted. The First Light press conference was attended by several Twitter correspondents, who sent out their impressions on this feed. @NASA_SDO was where Comet Lovejoy reappeared as the Phoenix comet and where Comet ISON never even showed up. I hope the 17K followers keep up with the SDO updates on @NASASunEarth and @TheSunToday.
Many thanks to @AleyaJean for bringing Twitter to SDO! #SadToSeeItEnd
Wednesday, June 11, 2014
Makes you want to get up early in the morning just to see what's happening on the Sun!
Tuesday, June 10, 2014
It's going to be an interesting week on the Sun!