The Great 2018 Mars Opposition

(NASA | JPL-Caltech | USGS)

This is the real deal – one of the big nights of the year. It’s the most famous, most feared planet coming extraordinarily close to Earth. Bang the drums. Bring your in-laws to Mayan pyramids and toss them off. Or just pull up a chair and dig the science.

The fun and games begin Friday night, July 27. That’s the date of the Great 2018 Mars Opposition. That’s when the Sun, the Earth and the planet Mars form a straight line in space. Mars rises just as the Sun sets. Mars, now very close to Earth, is exceptionally brilliant. And it’s out all night long.

By coincidence, Friday night is also the July Full Moon. So the brilliant orange planet and the Full Moon float next to each that night. Talk about easy astronomy.


The eccentric and tilted Martian orbit delays the time of that planet’s very closest approach until Tuesday night, July 31 – not that you’ll notice any difference in its appearance. Look for Mars either night or both nights. But don’t miss it. It hasn’t come this close to us in 15 years, and it won’t again approach this near until the year 2035.

Maybe a little background is in order: Fast-moving Earth catches up to slower Mars every two years and two months. So, after that 26-month interval, Mars returns to our neck of the woods and comes close again, making it brighter than usual. But such Martian oppositions are not created equal. If the meeting of our two worlds happens between July and September, as it does this time around, then Mars is exceptionally close and exceptionally bright. That’s because this is the month when Earth is always farthest from the Sun, while Mars is in the part of its orbit that is closest to the Sun and the Earth. This is what causes the gap between our two orbits to be narrowest in summer.

So Mars is now even brighter than Jupiter, which doesn’t happen very often. 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 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.

I’ll be honest with you: It’s a challenging telescope target. It may be larger than normal, but Mars still has a small disc that looks only about half the width of Jupiter, and it appears wiggly and blurry in our region’s typically smudgy air. So just gawking at it with the naked eye may offer the easiest and best method for celebrating this extraordinary approach of the Red Planet.