This May 2016 offers two unique astronomical experiences, a Blue Moon and a Mars Opposition within days of one another.
A Blue Moon occurs when a Full Moon occurs twice in one month, this year on May 21st. The term has nothing to do with the moon’s visible apperance being blue. Attached is a previous StarscapeScientific article on the occurance of a Blue Moon.
A Martian Opposition occurs every two years and is simply the time in which the Earth and Mars are cloest in orbit. Since Mars has an elliptical orbit, a favorable opposition (with respect to viewing through a telescope) is only once or twice in several decades. This year is a favorable opposition in that the planets disk will swell from less than 11 arc seconds to over 18 arc seconds since early May, with the greatest diameter on May 30th (arc seconds are a means of measuring a celestial bodies apparent size). The planet will be at it’s brightest however in apparent magnitude on May 22nd, at which time it will be almost as bright as Jupiter. Located in the head of Scorpio, Mars will oushine anything in the area being bright red. The brightest star in Scorpio is also a rudy red, but will be much less brighter than Mars.
A small telescope will show Mars as a small ruddy disc, possibly showing the southern polar ice cap. With an intermediate to large backyard telescope under ideal seeing conditions, many albedo features can be onserved and identified. The following image shows some of the features which can be seen with patience and waiting for moments of good seeing.
The brightness of the Full Moon should not interfere, with Mars appearing so bright. The apperance of both in the late evening/early morning sky along with Saturn should make for a notable night sky adventure.