Mercury, our solar system’s smallest planet, made a big mark on astronomical observations today when it transited the Sun for the first time since 2016. The transit, which occurs when Mercury passes between Earth and the Sun, lasted for almost six hours in total, offering skywatchers ample time to scope the perfectly round black dot against our home star’s roiling plasma surface. Check out glimpses of the phenomenon below to tide you over until the next viewing, which won’t happen until 2032.
On Monday, Nov. 11, beginning at about 7:35am ET (12:35 UTC), the planet Mercury will pass directly in front of the Sun. This event is called a transit, and the next #TransitofMercury visible in the U.S. won’t be until 2049. See how to watch, safely: https://t.co/tWbYjf1v1P pic.twitter.com/FlZwKx3yCt
— NASA Solar System (@NASASolarSystem) November 7, 2019
According to a NASA blog post describing the event, a transit of Mercury only occurs 13 times a century, and is significant not only because of the show it puts on—watching the jet-black speck cross the Sun’s surface is a brilliant reminder of how tiny planets are relative to our star—but also because the event has helped to facilitate numerous scientific breakthroughs. The NASA blog post notes that the transit of Mercury has helped to determine the absolute distance from the Earth to the Sun, for instance, and gives us a better sense of how planets and stars move through space.
Transits can even reveal the location of planets far beyond our own solar system. Instruments on observatories like @NASA_TESS can detect the dimming of a star when planets cross its face. We’ve discovered thousands of worlds this way — follow @NASAExoplanets for the latest. pic.twitter.com/JNtgQiTKkB
— NASA Solar System (@NASASolarSystem) November 7, 2019
Along with helping to determine distance measurements and movements of celestial objects, the transit of Mercury also helps to inform astronomers as to how much a given star’s light dims when a planet passes between it and our telescopes here on Earth. This is a big deal because it stands as a reference that can be used when determining whether or not exoplanets are transiting stars in other solar systems.
For the next few hours, Mercury will pass between the Earth & the Sun, silhouetting it against our home star. As you watch the #MercuryTransit:
? Use solar viewing glasses
☀️ Don’t look directly at the Sun
? Use a telescope with solar filtersMore: https://t.co/ezQOp4BQ7T pic.twitter.com/HmDGbC7ypm
— NASA (@NASA) November 11, 2019
All the cool science aside, however, the show the transit puts on really is magnificent. Check out the GIFs and clip above for a sense of the wonder the event inspires, or a longer video (below) of the 2016 transit made available by NASA.
What do you think of this 2019 transit of Mercury? Are you amazed by how tiny an entire planet is against the backdrop of the sun, or are you just waiting for the next solar eclipse? Transit the comments section with your opinions, people!
Images: NASA/Bill Ingalls
