A transit is when the body passing in front of the other body only partially blocks it (like Mercury transiting the Sun and all those \u201ctransiting exoplanets\u201d that ground-based telescopes and Kepler have been discovering).<\/p>\n
Finally, an eclipse occurs when one body passes into the shadow of another body and disappears at least partially.<\/p>\n
So is the Aug 21st Solar Eclipse (who\u2019s shadow path crosses North America) an eclipse? Well, it all depends on your viewpoint.<\/p>\n
When the Moon blots out the Sun, the Earth<\/em>, by falling into the Moon\u2019s shadow<\/em>, is eclipsed<\/em>.\u00a0 The Sun is not eclipsed. It is correct to say is the Moon<\/em> has occulted<\/em> the Sun.<\/p>\n Thus, August 21st perhaps is more correctly categorized as a solar occultation. On the flip side, all Lunar Eclipses are real Eclipses, the Moon disappears in the shadow of the Earth (the Moon dims due to the absence of light caused by the Earth\u2019s shadow).<\/p>\n The event of July 10th<\/sup> had a predicted ground path as described here http:\/\/www.boulder.swri.edu\/MU69_occ\/july10.html<\/a>.<\/p>\n On board SOFIA, we had Marc Buie and Simon Porter, the experts in the computing the path of 2014MU69 who were updating this exact timeline based on the most recent HST measurements of 2014MU69 (as of Jul 4th<\/sup>) just the day before flight.<\/p>\n SwRI Scientists Simon Porter, Marc Buie, and Eliot Young will fly on SOFIA as Guest Observers to catch MU69’s shadow.<\/p>\n At the time of flight takeoff, SOFIA would be hunting a shadow center intercept time of 07:49:11 UTC with an interception position at Lat 16d24.2m S, Lon 175d2.4m W. The duration of the dip in the light curve would be extremely small, less than 2 seconds, as MU69 is a very tiny object (diameter is estimated to be between 10-40 km) a long way away (43 AU; or 10 AU past Pluto). A very challenging occultation to capture.<\/p>\n The flight planners and navigators aboard SOFIA can position the aircraft with the precision need for this measurement (within 10 km; and 1 second). I\u2019m eager to witness first how this type of flight plan unfolds over the night.<\/p>\n Time to board!<\/p>\n July 10, 2017 We have a very different type of science flight tonight, a timed-event. This time the science focus is getting the SOFIA aircraft to be located over a specific latitude and longitude on Earth at a certain elevation at a specific time. We are flying an occultation flight. SOFIA has done this twice … Continue reading Carpe Umbra<\/span> ![\"IMG_5624\"](\"\/KES\/wp-content\/uploads\/2017\/07\/IMG_5624.jpg\")
<\/p>\n![\"IMG_5669-mod\"](\"\/KES\/wp-content\/uploads\/2017\/07\/IMG_5669-mod.png\")
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