Mars Eclipsed by the Moon

January 13, 20205

When the Moon covers the Sun, we call it an eclipse. When the Moon covers anything else, we call it an occultation, but it means the same thing: the Moon is closer to us than any other celestial object and so it can pass between us, making the more distant object disappear.

The Moon occults Mars on January 13, 2025. Moon’s position shown every 15 minutes. You won’t see most of the background stars because the Moon’s glare is too bright. I’ve removed that from the image to make it easier to see the motion. This view shows the field of view of typical household binoculars. (Image: Stellarium)

The Moon will occult Mars on Monday, January 13, 2025, and much of North America will be able to see at least part of the event. While you might be able to watch it with the unaided eye, an ordinary pair of binoculars will give you a better view.

For southern Manitoba, the Moon will begin to cover Mars at about 8:17 p.m. Central Time. (For times for other locations, see the link below.) It will take more than 30 seconds for the Moon to move far enough to cover Mars completely, so it will “fade out” rather than disappear in a flash. The Moon will keep moving and begin to uncover the red planet at about 9:06 p.m. Central, with a similar “fade-in” period.

Observing Tips

Use binoculars mounted on a tripod or a telescope if you can - you’d hate to have your arms get tired from holding the binos just at occultation time. Dress very warm!

Another point: The Moon is slightly past Full Moon, and so the left edge is fully illuminated, but the right edge has a very slight shadow. This means that while Mars will disappear behind the Moon’s visible edge (or “limb”), it will actually reappear a little bit away from the visible edge. This caught me by surprise during the last Mars occultation.

If it’s clear I’ll be live-streaming the event on my Facebook page and YouTube Channel. Join me!