An Earth-orbiting spacecraft simply skilled an uncommon phenomenon: a lunar transit and an Earth eclipse on the identical day.
On July 25, at completely different instances, each the moon and Earth handed between NASA’s Solar 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 modifications within the solar’s magnetic area. These information 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 nearly repeatedly since May of that 12 months.
To maintain a continuing eye on the solar, SDO is in a geosynchronous orbit round Earth, which means it circles the planet as soon as day by day. The airplane of its orbit is angled relative to Earth’s rotational axis, which retains the planet out of the way in which of its observations. This means the spacecraft normally has a view of the solar.
But often, the moon blocks that view. Several instances per 12 months, 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 blog. It was additionally the deepest, masking as much as 62% of the solar’s disk and lasting about 50 minutes.
Earth additionally often passes between SDO and the solar. SDO’s orbit is designed to attenuate these interruptions to the craft’s common observations, however roughly twice per 12 months, Earth blocks out the solar for a brief interval every day. Each of those “eclipse seasons” lasts round three weeks, in accordance with NASA. SDO is within the midst of its 31st eclipse season, which started July 10 and can final till Aug. 7.
Beginning round 6:30 UTC, about three hours after the moon completed its transit, Earth utterly blocked SDO’s view of the solar. The complete eclipse ended shortly earlier than 8:00 UTC, in accordance with the Solar Dynamics Observatory blog.
The two occasions look a bit completely different in SDO’s pictures of the solar. Because Earth’s ambiance absorbs some daylight, its shadow has a fuzzy edge. Meanwhile, 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 similar time, leading to a “double eclipse.”
Earth-bound eclipse spotters must wait a few more weeks to catch the following 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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