Watch Mercury Transit Across the Sun This Veteran’s Day
If you're reading this before 12:30 p.m. EST there's still time to catch an astronomical event that won't happen again for another thirteen years. According to The Verge, Mercury is transiting our Sun today, and you can witness its passage across Europe, Africa, and North and South America.
In astronomy, a planetary transit is what happens when a planet passes between the observer and its host star. In this case, Mercury is passing between the Earth and the Sun. Transits are one way we discover planets in other star systems: astronomers observe these distant stars and wait for "dips" in their brightness that indicate a planet may have passed between the stars and our telescopes.
The transit kicked off around 7:35 a.m. EST and Mercury will be visible on the face of our Sun as a tiny black dot for approximately five and a half hours until roughly 1:04 p.m. EST. It will be visible at sunrise to telescopes on the West coast and throughout the Midwest regions of Canada and the United States, while the East coast of North America and all of South America will be able to witness its full passage. Observatories in Africa and Europe will be getting their glimpse around sunset, and most of Asia and Australia will miss the action entirely since it will be nightfall in those regions.
Staring directly into the Sun is considered a universally bad idea, so there's no way to observe this transit directly. You would need a telescope or binoculars equipped with a special solar filter, and don't even think about trying to use solar eclipses glasses. (Mercury is too small to see with the unaided human eye, anyway.)
NASA's Solar Dynamics Observatory (SDO) will be sharing up-to-the-minute imagery of the transit in progress. You can follow along on their observations here. And there are several astronomy apps you can use to follow Mercury's transit across the sky.
Not that patient? Here's a video NASA made of the 2016 Mercury transit in progress:
Since there are just two planets between Earth and the Sun, we can only witness this astronomical phenomenon according to the orbits of Mercury and Venus. The next transit of Mercury won't happen again until 2032. The last transit of Venus occurred in 2012, and it won't happen again until 2117. When you consider how brief our years are as humans compared against the immensity of time it takes for an ordinary cosmological phenomenon to recur, suddenly something that happens "every" thirteen years seems like something worth watching.
Take a look at the images NASA SDO just released this morning.