You are here

Mars Opposition IV

May 21, 2016

Mars is earning its fearsome reputation this month. The planet named for the ancient god of war lines up opposite the Sun tomorrow. As a result, it shines brightest not only for this year, but for the next two years. It looks like a brilliant orange star. It stands close to the right of the full Moon as darkness falls tonight, with the planet Saturn and the star Antares below them.

Mars reaches “opposition” once every 26 months or so, as Earth overtakes the planet in our smaller, faster orbit around the Sun. Mars and Earth are closest around opposition, so Mars presents a bigger target than at any other time. That accounts for much of its brightness. The planet also reflects more sunlight directly toward Earth at opposition, just as the full Moon does, which intensifies its brightness.

Not all Mars oppositions are alike. The planet’s orbit is more lopsided than Earth’s orbit, so the distance from Mars to the Sun varies by more than 26 million miles. The best oppositions occur when Mars is closest to the Sun, as it will be in 2018. The worst occur when Mars is farthest from the Sun.

This year’s opposition is roughly half way between the two extremes, so Mars is putting on a good show. It’s in view all night, and outshines everything in the night sky except the Moon and the planet Jupiter.

Again, look for bright orange Mars quite close to the right of the Moon this evening. We’ll have more about Mars and its companions tomorrow.


Script by Damond Benningfield

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.