Get your observing equipment ready for some world-hunting.
Dwarf planet Pluto will reach its opposition, or brightest appearance in the sky, late on Wednesday (July 20). Stay up until dawn, and you can watch the third-quarter moon approach Mars in the brightening sky Thursday (July 21).
Be forewarned that Pluto is an observing challenge, as it is only visible in the largest of backyard telescopes. Its maximum magnitude will be 14.3, compared with naked-eye stars that shine at -6.
Still, we can at least point you to the area of sky Pluto currently occupies. According to astronomer Chris Vaughan of Astrogeo.ca (opens in new tab), who prepares Space.com’s monthly Night Sky calendar in cooperation with Simulation Curriculum, look for the medium-bright star Omega Sagittarii, which shines well to the left (east) of Sagittarius’ teapot-shaped asterism.
Pluto is roughly three finger-widths (3.5 degrees) north of the star. Or you can seek out the bright globular star cluster Messier 75; Pluto is two degrees to the lower right.
Happily, the moon and Mars are much easier to spot and will be visible to the naked eye.
The moon will rise early in the morning on Thursday as a waning crescent, starting at 12:32 a.m. local time in New York City. (Consult Timeanddate.com (opens in new tab) to find the rise time for your locality.) Mars should rise a few minutes later.
Wait until the moon and Mars are well above the horizon, around 2 a.m. local time. Find the moon, then look several finger-widths (4 degrees) to the upper right to spot Mars. The two worlds will share a single binocular field.
You’ll be able to follow them up at the sky through dawn, around 5 a.m. If you’re clouded out, you’ll be able to spot the two worlds again on Friday morning (July 22), although the moon will now be at the lower left of Mars.
In between, observers in eastern China, Japan and northeastern Russia can watch the moon go in front of (occult) Mars around 1500 GMT on Thursday, according to Vaughan.
Looking for a telescope or binoculars to observe Pluto, Mars or the moon? Our guides for the best binoculars deals and the best telescope deals now can help. Our best cameras for astrophotography and best lenses for astrophotography can also help you prepare to capture the next skywatching sight on your own.