On 2016 March 8 and 9, a solar eclipse took place over the Pacific Ocean. This eclipse was total -that is, the entire solar disk was covered by the Moon- over Indonesia and the central Pacific, starting at sunrise over Sumatra and ending at sunset north of the Hawaiian Islands. Additionally, large parts of South-East Asia, Alaska and Australia witnessed a partial solar eclipse. The path of totality had a maximum width of 155 km and the maximum duration was 4 minutes and 9 seconds at the point of greatest eclipse, which was over the waters of the Pacific Ocean.
Unfortunately, this eclipse took place during night time in Belgium, so it could not be observed from ground here. Luckily, we do have the PROBA2 spacecraft observing the Sun nearly continuously. Due to its sun-synchronous orbit, PROBA2 follows the terminator, the dividing line between day and night on earth, and was thus able to observe a partial solar eclipse. Because PROBA2 has an orbit of only 90 minutes, it passed through the Moon’s shadow and observed a partial solar eclipse two times on March 9: between 00:40 UT and 00:54 UT and again between 02:58 UT and 03:13 UT. Additionally, the Moon appeared two times in the field of view of the solar instruments onboard PROBA2, SWAP and LYRA, without obscuring the solar disk.
A movie simulating the SWAP observations on March 8 and 9 can be found here.
SWAP, an Extreme-Ultraviolet solar telescope, observes the solar corona in a passband centered on 17.4 nm. The structures we see in SWAP images have a temperature of approximately 1 million degrees. LYRA, an X-ray/Ultraviolet radiometer observes the total incoming light levels from the Sun in several wavelength bands.
We have collected all of our SWAP data products for this eclipse in one place for easy access.
Additionally every still image from the eclipse sequence, in all three of the varieties described above, is available via this link: http://proba2.oma.be/Events/2016-Mar-09-SolarEclipse/png_sequences/.
SWAP movies of the eclipse have been updated as soon as data from the spacecraft was available on the ground. Movies are also available in the three varieties discussed above, in MP4 format, compressed for web users and uncompressed for media users. (Media note: All movies are encoded using h264 at 25 fps.)
The two transits of the Moon in front of the solar disk were also captured in LYRA timeseries. For the occasion, we activated our backup unit (unit3) in parallel to the nominal one.
Interestingly, the second transit happened simultaneously to a C1.3 flare, as illustrated below:
All of the latest movies are available at the following link. These files will be overwritten periodically throughout the day as new data arrives, so users who would like the latest/best available movie should refresh the page. Link to the movies: http://proba2.oma.be/Events/2016-Mar-09-SolarEclipse/movies/.
All requests for media comments, data assistance, or planning requests can be directed to the SWAP and LYRA teams via firstname.lastname@example.org.
PROBA2 isn't just useful for eclipse observations! The PROBA2 PI-team welcomes research proposals for the seventh round of its Guest Investigator program for research based on SWAP and LYRA data analysis by scientists outside the SWAP and LYRA PI-teams. Learn more about our 7th GI call here.