Tonight after 10:30, look over to the southeast and you’ll see a remarkable triangle of celestial lights: Mars, Spica and the waning gibbous moon. For those who remember their geometry the threesome will form either an equilateral, isosceles or right triangle depending on the where you live and time of night.
Fiery Mars now outshines Spica and all the nighttime stars except Sirius, the brightest star in the sky. It’s rapidly approaching its April 8 opposition when our two planets will be their closest since early 2008. A closer Mars means a bigger view in the telescope – the planet’s disk has swollen to more than 13 arc seconds wide, large enough that observers with 6-inch and larger telescopes using magnifications of 150x and higher can spy a variety of dark markings on its dusty surface.
One of the most prominent Martian features this season is the north polar cap, but you’d better look quick. With summer underway in Mars’ northern hemisphere, the cap has been steadily shrinking, and now appears as small dab of white along the planet’s northern edge or limb.
For more on interesting things to see on the Red Planet in the coming weeks, please check out a recent article I wrote for Universe Today. You’ll also want to download Meridian, a free and useful program to help you know what features on Mars are facing you at any time of night or day.