An Earth-orbiting spacecraft simply skilled an uncommon phenomenon: a lunar transit and an Earth eclipse on the identical day.
On July 25, at totally different instances, each the moon and Earth handed between NASA’s Photo voltaic Dynamics Observatory (SDO) and the solar.
SDO research the solar‘s exercise, together with the photo voltaic wind (the stream of charged particles flowing from the solar), photo voltaic flares and adjustments within the solar’s magnetic area. These knowledge assist scientists forecast photo voltaic exercise that may have an effect on Earth. The spacecraft launched in February 2010 and has been observing the solar virtually constantly since Could of that yr.
To maintain a relentless eye on the solar, SDO is in a geosynchronous orbit round Earth, that means it circles the planet as soon as day by day. The aircraft of its orbit is angled relative to Earth’s rotational axis, which retains the planet out of the best way of its observations. This implies the spacecraft normally has a view of the solar.
However sometimes, the moon blocks that view. A number of instances per yr, the moon partially eclipses the solar from SDO’s perspective. The July 25 lunar transit, which started round 2:45 UTC, was SDO’s fourth partial eclipse since April, in accordance with SDO’s weblog. It was additionally the deepest, protecting as much as 62% of the solar’s disk and lasting about 50 minutes.
Earth additionally sometimes passes between SDO and the solar. SDO’s orbit is designed to reduce these interruptions to the craft’s common observations, however roughly twice per yr, Earth blocks out the solar for a brief interval every day. Every of those “eclipse seasons” lasts round three weeks, in accordance with NASA. SDO is within the midst of its thirty first eclipse season, which started July 10 and can final till Aug. 7.
Starting round 6:30 UTC, about three hours after the moon completed its transit, Earth fully blocked SDO’s view of the solar. The whole eclipse ended shortly earlier than 8:00 UTC, in accordance with the Photo voltaic Dynamics Observatory weblog.
The 2 occasions look a bit totally different in SDO’s pictures of the solar. As a result of Earth’s ambiance absorbs some daylight, its shadow has a fuzzy edge. In the meantime, the moon, which has no ambiance, carves a crisp circle out of the solar’s disk.
This is not the primary time each Earth and the moon have gotten in SDO’s approach on the identical day. In 2015 — and once more in 2016 — each our bodies eclipsed the solar from SDO’s perspective on the identical time, leading to a “double eclipse.”
Earth-bound eclipse spotters must wait just a few extra weeks to catch the subsequent occasion. A partial photo voltaic eclipse shall be seen from New Zealand and components of Australia on Sept. 21. The subsequent complete photo voltaic eclipse — which shall be seen from components of Greenland, Iceland, Russia, Spain and Portugal — will happen on Aug. 12, 2026.
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