Wednesday, July 20, 2016
Wednesday, July 13, 2016
Wednesday, July 6, 2016
Friday, June 24, 2016
The impact of the CME was not very dramatic when it reached Earth a few days later. But the energies of the radiation belt protons and electrons were increased enough that they caused an electronic component to arc and fail. There were several attempts to revive Telstar 401, but it was eventually declared a loss.
According to the Union of Concerned Scientists, there are almost 500 satellites currently operating in geosynchronous orbits about the Earth. Most of them are in the geostationary belt that allows them to appear stationary in the sky. There are about 100 defunct satellites in graveyard orbits further away from the Sun. But it is the failed satellites and spent boosters that blunder along and show up on the SDO conjunction report every month or so.
Telstar 401, a true ghost of space weather!
Monday, June 20, 2016
Today I would like to share another picture from the May 9, 2016, Mercury transit. This is a composite created by Monica Bobra at Stanford University. It's an excellent view of the transit from 2nd contact to 3rd contact, with an image every 20 minutes. Creating these composites takes a good bit of art. You can't just add the images together as that blurs the background image of the Sun. You have to take cutouts around the planet and reinsert them in a selected background image.
You can see the paths of Mercury are slightly different in the two images. The MDI path is closer to the solar equator and tilted at an angle to the path in the HMI image. These differences are caused by the different viewpoints of the transit from the two spacecraft. Similar differences are what were measured to determine the size of the astronomical unit (AU) during the Venus transits of the 1700 and 1800's.
Friday, June 10, 2016
Friday, June 3, 2016
Congratulations to the EVE team for re-flying the payload after last year's lunch problems. Thanks to the Wallops flight crew and the White Sands Missile Range personnel who actually do the launch and recovery.