About 13 times each century, the closest planet to the sun passes between Earth and our star, treating us to a rare transit event. Your next chance to catch this astronomical wonder is Nov. 11. This won’t happen again until 2032.
Why are these Mercury transits so rare? It has to do with the planet’s highly eccentric orbit and how it meshes with Earth’s orbit. Mercury’s distance from the sun can vary quite a bit, and its orbit has an incline of 7 degrees compared with ours. That means the three of us don’t come into line very often.
The transit will be visible for a large part of the globe, including most of North America, South America, Europe and Africa. Sorry, Australia, you won’t be able to witness it in person.
If you want to get pumped about this cosmic event, then check out this NASA video of the 2016 Mercury transit.
Time the transit
Mercury will kick off the festivities at 4:35 a.m. PT. Don’t set your alarm too early if you’re on the West Coast of the US, though. You’ll have to wait for the sun to rise before the transit is visible.
Mercury will take its sweet time strolling across the face of the sun: The transit will last about 5.5 hours.
Tools of the transit
Important: Don’t look at the sun with the naked eye. You’re going to need the right equipment to see the transit.
Mercury appears as a dainty dark spot moving across the sun, so your regular solar eclipse glasses won’t work here. “Because Mercury is so small from our perspective on Earth, you’ll need binoculars or a telescope with a sun filter to see it,” says NASA.
However, you can’t just slap on your eclipse glasses and then hold up your binoculars. The space agency warns: “Do not combine solar viewing/eclipse glasses with binoculars. You can severely damage your eyes!” This can cause the solar film in the glasses to melt, so don’t cook your eyeballs.
If you don’t have the gear (or an astronomy buddy with the gear), then look for a transit viewing party in your area. Astronomy clubs and museums are likely places. Check out NASA’s searchable guide to clubs and events to find local space fans.
Your view of the transit will also depend on weather. Here’s hoping for clear skies. If you can’t get access to the right equipment or if clouds threaten to ruin your Mercury viewing, then head online for the next best thing.
Watch the transit live online
The other way to catch the transit action is to kick back in your home or office and enjoy a livestreamed event. The Virtual Telescope Project will offer an online observation session starting at 4:30 a.m. PT.
NASA’s Solar Dynamics Observatory team will share an almost-live version of the transit using SDO images.