Step outside shortly after sunset on Monday, Jan. 13, and look low in the east-northeastern sky.
There you’ll see the rising full moon, and just below it you may notice a glowing orange “star.”
This isn’t a star at all; it’s the Red Planet Mars.
Mars now appears against the stars of Gemini, the Twins, which of course lie trillions of miles farther and appear only roughly along the same line of sight.
The planet reaches its closest to Earth during this orbital cycle on that night, when it lies only about 59.7 million miles away, much farther than the moon at only 236,192 miles distant.
Because the moon will be so brilliant on that night, you may need binoculars to spot Mars so close to the lunar disk.
Of course, if you own a small telescope or can visit your local planetarium or amateur astronomy club, you’ll get quite a close-up view of Mars at this time.
With even the lowest magnification you’ll easily see its orange disk, but a larger telescope with higher magnifications will show some dark features on the planet’s surface.
Mars will be in a great position for viewing all month long.
On the evening of Jan. 13, however, don’t just glimpse at Mars and quit because, if you’re patient, you can watch the moon play a game of hide-and-seek with the Red Planet.
What you will see (and when) depends on where you live, but if you’re in North America you’ll be able to watch the show.
Why? Because on that evening the moon will drift in front of Mars and create what astronomers call an “occultation.”
When and where you watch it will determine whether you’ll see Mars or if it will be hidden behind the solid disk of the moon. The occultation will be visible to skywatchers throughout North America, weather permitting.
Stargazers on the West Coast, for example, will see the planet’s vanishing act (its “ingress”) behind the moon’s eastern limb around 5:49 p.m. PST.
From the Denver area, the ingress will occur at around 6:57 p.m. MST. From the Chicago area, watch for the planet to disappear around 8:07 p.m. CST, and from New York City, Mars will vanish at around 9:21 p.m. EST.
It’s not only the planetary disappearing act that will be of interest. Not long after the planet vanishes, it will reappear on the opposite side of the moon.
Spotting this, however, will be more challenging since it’s tough knowing exactly where Mars will emerge from behind the moon’s western limb.
From the West Coast, this “egress” will occur at around 6:45 p.m. PST.
From Denver, watch for it around 7:56 p.m. MST. From the Chicago area, around 9:16 p.m. CST, and from New York City, around 10:36 p.m. EST.
Because the exact times of this occultation depend precisely on your location, and the ingress and egress occur quite fast, you’d be wise to get more accurate times for your location by calling your local planetarium, observatory or amateur astronomy club.
And, of course, always plan to begin your watch at least 15 minutes early so you don’t miss either event!
