Remember, Mercury is tiny a world, just 1.4 times the diameter of our Moon, at 4,880 kilometers across. At about 9″ arc seconds across during the transit, it took Mercury seven and a half hours to race across the 30′ (over 180 times the apparent size of Mercury as seen from the Earth) disk of the Sun.
The video has an ethereal three dimensional quality to it, as we seem to race along with the fleeting world. You can see the granulation in the dazzling solar photosphere whiz by in the background.
Big Bear Solar Observatory Telescope Engineer and Chief Observer Claude Plymate explains some of the technical aspects of the captured sequence:
“John Varsik assembled (the video) from our speckle reconstructed broadband filter images. The images were taken with a high speed PCO2000 CCD camera. Bursts of 100 frames were taken at a cadence of 15 seconds. After flat fielding and dark subtraction, speckle reconstruction is used on each burst to generate the final single frame. Exposure time was 1.0 ms through a broadband TiO (7057A, 10A FWHM) filter.
Our actual primary science data was data taken with a fast scanning spectrometer that very quickly produces 2D Na D-line maps. The objective was to measure the Na distribution in Mercury’s exosphere in absorption.”
So there’s some science there as well, as measurements taken from Big Bear will make a fine comparison and contrast with NASA’s measurements of the tenuous exosphere of Mercury measured by the MESSENGER spacecraft.
Based on the shores of Big Bear Lake in the San Bernardino Mountains 120 kilometers east of downtown Los Angeles, the Big Bear Solar Observatory employed the 1.6-meter New Solar Telescope (NST) to follow the transit. The NST is the largest clear aperture solar telescope in the world currently in use. Capable of resolving features on the Sun just 50 kilometers across, the mirror blank for the NST was figured at the Mirror Lab at the University of Arizona in Tucson and served as a proof of concept for the seven mirror Giant Magellan Telescope currently under construction.
The Big Bear Solar Observatory is managed under the New Jersey Institute of Technology and is funded by NASA, the United States Air Force and the National Science Foundation.
The Big Bear Solar Observatory is also part of the GONG (Global Oscillation Network Group), a series of observatories worldwide dedicated to observing the Sun around the clock. It’s strange to think, but in a sense, we live inside the outer atmosphere of our host star, and knowing just what it’s doing is of paramount importance to our modern technology-dependent civilization.
An awesome capture, with some amazing science to boot. Big Bear will also get a sunrise view of the November 11th, 2019 transit of Mercury as well:
The BBSO operation is supported by NJIT, US NSF AGS-1250818, and NASA NNX13AG14G grants, and the NST operation is partly supported by the Korea Astronomy and Space Science Institute and Seoul National University and by the strategic priority research program of CAS with Grant No. XDB09000000″.
On May 9, 2016, Mercury passed directly between the Sun and Earth. No one had a better view of the event than the space-based Solar Dynamics Observatory, as it had a completely unobstructed view of the entire seven-and-a-half-hour event! This composite image, above, of Mercury’s journey across the Sun was created with visible-light images from the Helioseismic and Magnetic Imager on SDO, and below is a wonderful video of the transit, as it includes views in several different wavelenths (and also some great soaring music sure to stir your soul).
Mercury transits of the Sun happen about 13 times each century, however the next one will occur in only about three and a half years, on November 11, 2019. But then it’s a long dry spell, as the following one won’t occur until November 13, 2032.
(Note: Awesome images are being added as they come in!)
Update: Here’s two more amazing videos of yesterday’s transit of Mercury that have come our way. First: double solar transits featuring Mercury, the International Space Station and a low flying plane right here in the skies of good old planet Earth courtesy of (who else?) Thierry Legault:
And here’s one of the very few sequences we’ve seen of the transit with foreground, captured at sunset by Gadi Eidelheit based in Israel:
Special Guest: Howard Trottier, a physics professor at Simon Fraser University (SFU) in British Columbia, Canada. Dr. Trottier has recently devoted his time to the development of SFU’s unique Astronomy public outreach program. In the heart of SFU’s main campus is a “”Science Courtyard,”” a high-profile public space devoted to astronomy and anchored by a state-of-the art outreach and teaching observatory. You can learn more about this amazing program here.
We’ve had an abundance of news stories for the past few months, and not enough time to get to them all. So we’ve started a new system. Instead of adding all of the stories to the spreadsheet each week, we are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!
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