Moon photobombs Jupiter, JUICE antenna fixed

Jupiter issue! The Moon blocks it and a spacecraft is fixed on its way to the planet

The edge-on disk galaxy NGC 5866. Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA); W. Keel (University of Alabama, Tuscaloosa)

May 16, 2023   Issue #565

What’s Up?

Look up! There’s stuff to see in the sky!

If you’re an early riser then you may get a treat on Wednesday (tomorrow, May 17) morning: The Moon will occult Jupiter!

That means for some locations, the Moon will appear to pass directly in front of Jupiter, blocking it from our view. I’ve seen a few of these and they’re always cool — I wrote about the Moon occulting Mars last December both here on BAN and for Scientific American, if you want some background.

The event occurs very roughly at 11:30 UTC (so, for example, 05:30 for me in Mountain Time). The exact time changes for different locations, so have a care! The Lunar Occultations website has timings for various locations around the world.

But that doesn’t mean everyone gets to see it. For example, it happens after the Sun is up for the US east coast. The Moon is just 5% illuminated at the time, an extremely thin crescent, so it’ll be tough to spot if the sky is bright. For me, near Denver, it’ll be strong twilight (and likely cloudy, because of course) with the Sun rising just minutes later. If you live on the west coast it’s better for lighting, but Jupiter and the Moon will be lower in the sky, so again that makes it a bit more difficult to observe. Earth and Sky has more info.

The Moon, Jupiter, and Jupiter’s moons just a few minutes before the occultation. This is the view from near Boulder, Colorado. Credit: SkySafari

If you want to try to observe this, get up early so you have time to spare. The pair will be very low in the sky just to the north (left) of due east, maybe just a few degrees off the horizon. Jupiter will appear as a very bright star, and the Moon will be an extremely thin crescent. Jupiter will actually be easier to spot, most likely.

The view by eye will be cool, since it takes almost a full minute for the Moon to slide all the way across Jupiter, so you’ll see the planet dim over that time. If you have binoculars it’ll be better, since the big Jovian moons will be visible, too, and the moon will cover them as well. A telescope is probably best if you use a low power eyepiece.

I’ll note that you should be careful though, because the Sun will be not too far away, and you don’t want to accidentally see it through your binocs or telescope. Be super careful.

Jupiter will reappear on the other side of the Moon (the side not illuminated by the Sun, so it’s tricky to see) about 55 minutes later, again depending on location. By this time the Sun will be fully up for me, so I won’t be watching this part even if it’s not raining where I am.

And if you see it and get photos, post ‘em on social media! I’d love to see them.