We’re about to see one of the truly great sky events of 2018. First, Mars’ best opposition in 15 years happens July 26–27. Second, Mars comes closest to Earth on July 30–31. And finding it requires no sky knowledge. It’s extremely bright and very red!
In the Martian opposition, Mars is aligned with the Sun with Earth right in the middle. This alignment causes Mars to be very close to us, and to rise in the east just as the sun sets, climb to its highest point at midnight, and shine brightly all night long. The Red Planet shines at its brightest best in Earth’s sky.
Technically, the opposition is on July 27 (05:00 UTC), but this means it happens during the night on July 26 (1 A.M.EDT, 10 P.M.PDT). Translate UTC to your time.
If you missed it, no worries, because Mars will still hover near the full Moon the night of July 27. It’s that very bright red object shining all night long on Friday night. Could finding it be any easier?
Mars Closest Approach to Earth
The very closest approach of Mars actually unfolds a few nights later, July 30–31. Technically, Mars be a hair brighter then, but nobody will notice the difference.
Either night finds Mars brighter than even Jupiter, which does NOT happen very often!
You can actually be lackadaisical and look for Mars anytime this entire next month. But don’t ignore it. It hasn’t come this close to us since 2003, and won’t again approach this nearby for another 17 years.
Image: In 2018, Mars will appear brightest from July 27 to July 30. Its closest approach to Earth is July 31. That is the point in Mars’ orbit when it comes closest to Earth. Credit: NASA
Why is it so close? Well, Earth meets up with Mars every 26 months, but when that happens, the gap between our orbits can be as wide as 70 million miles or as narrow as half that. So happens, July is when Earth is always farthest from the Sun and thus potentially closer to Mars. And August is when Mars is closest to the Sun and hence unusually near to us. Thus a summertime opposition offers the best close-up meeting between our two worlds.
How to View Mars
At opposition, the Red Planet will line up with the Sun and rise just as the Sun sets on the horizon. Look for the Red Planet ascending in the southeastern skies, creeping up towards the Moon, then moving across the sky during the night.
After Venus sets in the West at around 10 p.m., Mars is actually the brightest star in the entire sky for the rest of the night. Plus it’s distinctly orange-yellow. You just can’t miss it.
But remember: if you were trying to miss it, you couldn’t succeed on Friday night because it’s that brilliant orange star next to the Moon. And it will remain the most brilliant starlike object for most of the night for the remainder of the summer.
So, what to do with Mars? It’s not an easy telescope target because even now, Mars has a small disc about half the width of Jupiter, which requires a fair amount of magnification, which in turns magnifies any wiggles in the air. Bottom line: It usual appears smudgy through telescopes, though it’s definitely worth a shot on slightly hazy nights when stars are not twinkling.
But just staring at it with the naked eye may offer the most satisfying and certainly the most venerable way to salute this unusually close approach of the Red Planet.
This is a great time to check out Mars, especially if you’re a beginner sky gazer!