July has been like Christmas-come-early for stargazers and space fan, but the astronomical grand finale is still to come. This weekend, some Earthlings will be graced with a total lunar eclipse while Mars will be the closest to Earth that it’s been in 15 years. Here’s the low-down on what to look for, when, and how best to see it all.
What’s Going On?
If you’ve been paying attention, July has provided some truly excellent stargazing. Throughout the month, the night sky has been on rare display. Saturn and Jupiter are putting on brilliant shows, while the red star Antares and the bluish star Spica have been extremely visible.
However, Mars has been the real showstopper, causing many astronomers to dub this “The Month of Mars.” Because the Martian orbit does not track a perfect circle around the sun, its distance from the Earth changes dramatically over time. This month, it will pass incredibly close to Earth (in astronomical terms) and simultaneously cross adjacent to the eclipsed moon in the sky. The combination of these two events will provide some of the best Mars-viewing of the last century.
When Is This Month’s Best “Mars-gazing”?
This Friday, July 27, Mars will fall perfectly in line with the sun, the Earth, and the eclipsed moon. From our perspective, this is when it will be at opposition to the sun and at peak brightness. It will be the fourth brightest object in the sky after the sun, the moon, and venus. In geek speak, it will top out at a -2.8 magnitude, which Skymania describes as “unmissable.” North Americans should look low in the southern sky where Mars will appear near the faint Capricornus constellation around 1 a.m. ET.
Four days later, on July 31, Mars will be its closest to Earth — less than 36,000,000 miles away — since July 2003. That year, the planet was nearer to us than it had been in 60,000 years. It won’t pass this close to us again until 2035, so this might only be a thrice-in-a-lifetime event.
What Can I Expect to See?
At peak visibility, even with the naked eye, Mars will appear as a brilliant, red-orange ball just above the southern horizon. Those with even basic, backyard telescopes could easily make out the details of major features like Syrtis Major, as well as the red planet’s polar ice caps, pock-marked red deserts, and black volcanic plains. Sadly, however, most of these are currently obscured by a dramatic, global dust storm on Mars. Still, it will be a spectacular and rare display.
Folks in the southern hemisphere are guaranteed the best show with the least amount of atmospheric interference from the Earth. In addition to witnessing Mars at its brightest, they’ll also be treated to the longest lunar eclipse of the 21st century. But, just about everyone on Earth will be able to see the dramatic display in some form.