Mercury is gliding across our view of the sun today in a rare celestial treat.
This event is called a “transit,” and it happens when a planet passes between Earth and its star. Within our own solar system, we only see transits of Venus and Mercury, since those are the only planets between us and the sun. But when it comes to other star systems, NASA telescopes can hunt for new exoplanets by watching for tiny dips in a star’s brightness caused by transits of orbiting planets.
We won’t see a Mercury transit again until 2032. Mercury only makes this transit about 13 times per century.
The last transit was in 2016; NASA satellites recorded footage of the tiny planet crossing the blazing disk of the sun.
Mercury is the smallest planet in our solar system, so to watch the transit, you’ll need special equipment as well as protection for your eyes.
Mercury will take five-and-a-half hours to cross in front of the sun on Monday.
You should not try to watch this event directly, since you’d risk severe eye damage.
Many local museums and astronomy clubs are hosting viewing parties with all the safety equipment you need.
Don’t get your hopes up for a Venus transit next — that won’t happen until 2117.