As the sun begins to rise on Tuesday, the moon will wedge itself into Earth’s orbit to put on a celestial show — part of one, anyway.
A partial solar eclipse will be visible from Europe, northern Africa, the Middle East and Asia. The eclipse will become visible first in Reykjavik, Iceland, at 8:58 a.m. local time; where the sun will eventually be about 20 percent covered (sunrise is at 8:30 a.m.). By 11 a.m. in London, the moon will block 15 percent of the sun. The shadow will be peak around 4 p.m. in Chelyabinsk in Russia’s southern Ural region, which is expected to get 79 percent coverage, before waning in New Delhi at 5:30 p.m. with 44 percent coverage.
Because the moon is smaller than Earth, the moon’s shadow covers only a small part of Earth’s surface and is visible only from certain regions. (Sorry, America, this one’s not for you. But your time is coming.)
How does a solar eclipse work?
A solar eclipse occurs when the moon blocks the sun either in part or in totality, as seen from Earth. As the moon makes its orbit around Earth, and as Earth orbits around the sun, the moon gets caught in the middle and casts a shadow on Earth. Anyone standing in that shadow will be able to see the solar eclipse.
Robert Massey, the deputy executive director of the Royal Astronomical Society in the United Kingdom, said the “wow” factor varies depending on where you observed it.
In London, he said, the eclipse will be “a bit wow,” but in Chelyabinsk, which is no stranger to astronomical events, the eclipse will produce a “medium wow.” In India, eclipse viewers will get to see the moon take a bite out of the sun as the sun begins to set, “which in itself is a spectacular thing to see,” Dr. Massey said.
Either way, Dr. Massey said, “if you’ve never seen one before, it’s a great experience.”
Of course, it all depends on the weather forecast. A cloudy day will ruin any hopes of viewing.
How does this eclipse stack up against others?
The alignment between the moon and the sun is relatively rare. Because the moon’s orbit is slightly tilted, solar eclipses occur only when the moon crosses the plane of Earth’s orbit during a new moon. Eclipse windows happen six months apart. (The last partial eclipse was in April.)
That said, partial eclipses occur more frequently than total eclipses, when the moon fully blocks out the sun. But this particular partial eclipse will not produce a dramatic event, Dr. Massey said. For many, it will look like a cloud covering the sun.
“It will basically be a bite coming out of a sun,” he said. “It’s not going to be noticeably darker, even if you’re out. Your eye is so good at adapting.”
Grab your eclipse glasses.
If you’re planning to watch the eclipse in person, there is one important thing to remember: Never look directly at the sun. Solar eclipses can be especially dangerous because the sudden changes in luminosity do not give your eyes a chance to adapt. To view the show safely, you can either purchase a pair of special glasses that have solar filters or build a pinhole projector. You are guaranteed to feel like a child either way, but it’s worth the precaution.
“People need to understand it is not safe to look at the sun,” Dr. Massey said. “Even if it is 20 percent covered, that’s still leaving an enormous amount of uncovered sun.”
Eclipse glasses block out almost all of the sunlight, Dr. Massey said, so you’re able to see just the bite out of the moon as it comes in front of the sun. Telescopes with special solar filters are also an option.
Dr. Massey also recommended reaching out to a local astronomical society, which may have plans to host watch parties and can also answer questions. Or you can watch from the comfort of home. The Royal Observatory is hosting a watch party on its website. The Virtual Telescope Project will livestream the event from Rome. Everyone — even Americans — is invited.
Plan ahead, pack your bags.
People in the United States will get their chance to see an eclipse next month. A total lunar eclipse, when the moon passes through Earth’s shadow, will occur from Nov. 7 to Nov. 8 and will be visible from North America, South America and Eastern Asia. This will be the last total lunar eclipse for three years.