Friday, October 9, 2015
Wednesday, October 7, 2015
With the extended mission comes calibration maneuvers. The first is an EVE cruciform today from 1800 UTC (2:00 p.m. ET) until 2230 UTC (6:30 p.m. ET). SDO science data will not available during the maneuver but the AIA images on the SDO website will look like the Sun is zooming around in space.
Congratulations to the SDO Team for the successful proposal and winning another two years of watching the Sun and solar activity!
Monday, September 14, 2015
Check it Out!
HelioViewer. The motion of the Sun is caused by the telescope heating up as the Sun rises. SDO cannot run its fine guidance system without seeing the entire Sun. During an eclipse the fine guidance system is turned off and a little while after the eclipse it is turned back on.
Friday, September 11, 2015
NASA's Eclipse webpage showing the path of the solar eclipse. This is the first time a solar eclipse was visible on the Earth during an SDO lunar transit. SDO cannot see the entire solar eclipse because the Earth gets in the way. The Moon was at perigee (closest point to the Earth) for the Full Moon two weeks ago. That means it is at apogee (furthest point from the Earth) for the New Moon on Sunday. The Moon will appear to be a little smaller than average so a total solar eclipse is not possible this month.
On September 28, 2015 a total lunar eclipse will be visible from most of the United States, Europe, South America and Africa. SDO does not see lunar eclipses because we look the other way. Not to worry, SDO will see another Lunar Transit on October 12, 2015 from 1718 – 1733 UTC (1:18 – 1:33 p.m. ET). It will be a grazing transit. Because SDO will not be near midnight Mountain Time, this transit will not be seen at the surface.
I hope you enjoy the Alignment of the Four Most Important Objects in the Solar System.
Friday, August 28, 2015
Here's the latest from Karl Battams: "As I expected, the comet "pulled an ISON". I won't even describe it as a comet any longer. It's a rubble pile." (SunGrazerComets).
We see comets because they evaporate ices and other compounds from their surface. This cools the comet, but makes it disappear. The water ice that comes off the comet quickly turns into Hydrogen and Oxygen atoms. SDO sees comet tails when the oxygen atoms hit the electrons in the corona. We can use the tails to explore the Sun's magnetic field and corona.
Most Kruetz sungrazing comets are too small to make it to perihelion (Comet Lovejoy in December 2012 was the only exception). We can only watch as this comet goes behind the LASCO occulter disks and hope it continues to evaporate and be seen in SDO/AIA images.