Mars will pull a disappearing act Tuesday
If you want to see magic happen in the heavens, you’ll get that opportunity Tuesday when the moon makes Mars disappear and reappear 80 minutes later.
It’s called an occultation, which makes it sound more mysterious than it actually is. At 4:40 a.m. on Tuesday, give or take a couple of minutes depending on where you are, the moon will appear to pass in front of Mars. At about 6 a.m., Mars will reappear on the other side.
“I usually see it as being orange-ish, in terms of its overall color,” said John Keller, a planetary scientist who is the director of the Fiske Planetarium at the University of Colorado in Boulder. “Other people see red. What’s really interesting is that the moon is going to be a crescent moon. It will be the lit portion of the moon that will first cover Mars. You’ll see the crescent moon with a very bright Mars right next to it, then Mars will fade out. When it comes out the other side, it’s going to be (adjacent to) the unlit portion of the moon.”
Once the occultation begins, Keller said, it will take about a minute for Mars to disappear entirely. Over that minute, you will see Mars grow darker. The same will occur in reverse as the occultation ends; Mars will reappear faintly, gradually growing brighter.
“These things happen all the time in the solar system, but you normally need telescopes to notice the planet going in front of a star, or a moon going in front of another planet,” Keller said. “This is a really great naked-eye opportunity.”
The occultation will begin about an hour and 40 minutes after the moon rises, so look to the east. The crescent will be about a quarter-moon (the halfmoon occurs three days earlier on Saturday). Mars will appear to be on the left side of the moon before occultation, reappearing to the right of it afterward.