Astronomy buffs have a rare opportunity Monday to enjoy a rare treat in the sky: a view of planet Mercury as it transits in front of the Sun.
Although the closest planet to the Sun orbits every 88 days, the angles of the orbits of Mercury and Earth make Monday's event infrequent. According to Tim Collins, senior presenter at the Whitworth Ferguson Planetarium at Buffalo State College, people on Earth only get to view this, on average, about once per decade.
"The span is from about 7:30 a.m. until 2:30 p.m.," he said about the length of the transit. "It will be a very small dot passing across the face, very similar to how Venus did this back in 2012. It'll be very difficult to see unless you can magnify it."
It should go without saying, but one must never look directly at the Sun. Options for projecting the Sun's disk safely include a technique involving two sheets of paper. Poke a pinhold in one, then hold the second sheet below it, the latter serving as a screen on which the first sheet allows sunlight through the pinhole.
But given the small size of Mercury across the face of the Sun, a better option would be using a telescope that is fitted with a solar filter.
"A solar filter is a coating that is used on a special lens," Collins explained. "They are very easy to acquire. The best way to do it is go online. There are several telescope vendors that sell the appropriate dimension to your telescope. You need to know the diameter of your primary mirror in order to cover it correctly."
Planetarium staff will host viewings for the campus community in the plaza between the Student Union and the library until 2 p.m.
