July 24, 2024

More than half the solar system’s planets will align Monday in a rarely seen spectacle, arcing across a corner of the night sky.

Mercury, Venus, Mars, Jupiter and Uranus will parade across the sky, accompanied by the moon and a possible star cluster. While the scenario will be visible to the naked eye, astronomers recommend breaking out the binoculars or a telescope for a more detailed view.

The planets will be arrayed across the western horizon in an arc about 20 to 25 minutes after Monday’s sunset, according to Space.com, starting with Mercury and Jupiter. However, twilight’s brightness could mask them, Space.com warned, adding that the viewing window is only about 25 to 30 minutes.

The planets will also be so close to the horizon that any structure or sightline glitch could obscure them. “Your best option is looking out over a westward-facing shoreline that is perfectly flat and wide open with nothing to block your view,” Space.com said.

Slightly higher, but more discernible and with a longer viewing window, will be Venus, and above it to the left will be faint, greenish-hued Uranus. Mars is next on the list, higher up and cozying next to a crescent moon, according to Starwalk.

Monday is the best day to observe this phenomenon, but the alignment will be visible in the days leading up to and following the high point.

Before that, though, a massive asteroid the size of a skyscraper will whiz by Earth inside the moon’s orbit. Asteroid 2023 DZ2 is three times the size of the one that jangled nerves and blew out windows over the Russian industrial city of Chelyabinsk 10 years ago.

2023 DZ2 will not come anywhere near that close, but it will cruise about 100,000 miles away, halfway between Earth and the moon, NASA Asteroid Watch reports. This will happen at 3:51 p.m. Saturday, though that timeline could be tweaked as the observations pour in.

The newly discovered asteroid, which NASA estimates is between 141 and 310 feet across, will be traveling 17,426 mph on its way to the sun, EarthSky.org said.

“While close approaches are a regular occurrence, one by an asteroid of this size happens only about once per decade, providing a unique opportunity for science,” NASA said.