Although it’s much closer to us than many of the other planets, Mercury can be one of the trickiest to view in a telescope thanks to its close orbit around the Sun. The absolute best time to view tiny Mercury is to experience a Mercury Transit like the one coming up on May 9, 2016.
What is a transit?
A transit is like an eclipse in that it involves the alignment of multiple celestial objects. In an eclipse, the Moon passes between the Earth and the Sun. In a transit, a planet moves between the Earth and the Sun. Because the planets are so much farther away, they obstruct much less of the solar disk and appear as silhouetted dots moving across the face of the Sun.
Mercury is the smallest planet, and it’s also very far away from us. When it transits the Sun, it will only appear 1/158th the size of the solar disk. This transit will last approximately 7.5 hours from when it begins at 11:12 a.m. UMT (Universal Time). For more information about what this means for your time zone, keep reading.
When can I view the 2016 Mercury Transit from the United States?
Fortunately, observers in the United States are perfectly positioned to view most—if not all—of the May 2016 Mercury Transit. Depending on your exact location, the transit will begin within 2 hours after sunrise or will already be underway when the sun rises. Here’s when the transit will begin in a few of the largest US cities:
- In New York City, the transit will begin at 7:12 a.m.
- In Chicago, the transit will begin at 6:12 a.m.
- In Denver, the transit will already be underway at sunrise, 5:51 a.m.
- In Los Angeles, the transit will already be underway at sunrise, 5:56 a.m.
To calculate the time that the transit will begin in some other city, you’ll need to know when the eclipse begins in your time zone:
- Universal time (UMT): 11:12 a.m.
- Eastern time: 7:12 a.m.
- Central time: 6:12 a.m.
- Mountain time: 5:12 a.m.
- Pacific time: 4:12 a.m.
From there, you can look up the time of sunrise at your location. Here’s a free calculator you can use. For example, at TelescopesPlus.com HQ in Omaha, sunrise will be at 6:11 a.m. Since we’re located in the Central time zone, the transit will begin at 6:12 a.m. The timing couldn’t be better!
What special equipment do I need to view or photograph the transit?
As you might gather, if you want to view the Mercury Transit, you’ll be viewing the Sun directly. Solar astronomy is a rewarding hobby, but you must take special safety precautions to avoid damaging your eyes and telescope. You’ll find detailed safety information at the bottom of this article.
The good news is, with a proper, full aperture solar filter (like these from AstroZap), you should be able to view the Mercury Transit in most telescopes, even small aperture beginner telescopes. A telescope with automatic tracking is ideal since the transit will take several hours to complete.
If you want to step up your solar viewing experience, you can consider a Hydrogen alpha solar scope. To learn more about H alpha, check out our more detailed article on solar viewing.
As far as imaging goes, you can take surprisingly detailed images of the Sun just by holding your digital camera or smartphone up to the eyepiece. Telescopes.com also carries a wide variety of solar system cameras suitable for imaging the Sun. Combine these with a laptop computer and you’ll be on your way to great images and video.
A Word about Safety
We can’t stress this enough: NEVER attempt to observe the Sun without proper protection for your eyes and telescope. Viewing direct, unfiltered sunlight (even for an instant) causes permanent, irreversible eye damage including blindness.
Do not use a Herschel wedge or projection method when observing the Sun with a nighttime telescope larger than 70mm. Doing so can cause heat buildup inside the telescope, damaging its optics. Always use a solar filter that filters the light before it enters the telescope. Never use a solar filter that attaches to an eyepiece as they can crack with heat buildup, allowing unfiltered light to pass through to the eye. Proper solar filters include: approved solar glasses or solar viewing cards, full aperture solar filters for nighttime telescopes, and specialized solar telescopes.
To prepare for solar viewing, remove finderscopes and secure solar filters to all telescopes before taking them outside. Finally, don’t forget to wear a hat and sunscreen! Although the safety concerns with solar observing are real, once you take these basic precautions, you’ll be ready to have a great time viewing the Sun.
Get Personalized Help
Have questions about what gear you’ll need for the transit? Reach out to our Telescope Experts by phone or email. You can reach our Customer Support line at 1-800-303-5873. We're open 8 a.m. to 8 p.m. Central Time, Monday through Friday and 9 a.m. to 4 p.m. on Saturday.
After hours? Drop us an email at email@example.com. We'll get back to you as soon as possible, usually within 1 business day.
White light solar image taken with a 114mm ED refractor and Canon 350D DSLR. Courtesy Bryan Cogdell/Stellarscapes.