For those on the ground during today's total solar eclipse, the period of totality will last at most 2 minutes 40.25 seconds. In order to extend observation time to over seven minutes NASA will fly two of their three WB-57F Canberra research aircraft, based at Ellington Field near the Johnson Space Center in Houston. along the path of the eclipse at an altitude of 50,000 feet.
Researchers will capture the clearest photographs of the sun's corona to date using two telescopes mounted on the noses of each aircraft, possibly revealing nanoflares which are hypothesized as a mechanism for the heating of the corona.
In addition to examining Sol's corona, the flights will capture the first-ever thermal imagery of Mercury, allowing researchers to map the temperature variance across the surface of the planet.
Today's Featured Map illustrates the research portion of the planned flight paths of NASA 926 (red) and NASA 927 (blue). Key points along the paths are marked including the planned mission time (UTC). The black lines mark the edges of the path of totality. Thanks to Dr. Amir Caspi (astronamir on Twitter) of the Southwest Research Institute in Boulder, Colorado, principal investigator of the project, for his generous assistance with this map. Eclipse predictions are by Fred Espenak, EclipseWise.com.
Live video from the flights will be broadcast on NASA TV between when NASA 926 enters totality at 1:16 pm CDT and when NASA 927 exits totality at 1:24 pm CDT. This video coverage may be available on C-SPAN in areas which do not have a NASA channel. The Science Channel, The Weather Channel, and CBS may also carry live coverage of the flights.
The NASA flights will also be featured during two special programs. PBS NOVA's "Eclipse Over America" will air Monday evening, after the eclipse. The Science Channel's "Great American Eclipse" is a two-part special, with the second part airing after the eclipse on Monday. (The first part was broadcast last night.)