Mars at Opposition 2022: The Full Moon Occults Mars Wednesday Night

A rare event transpires Wednesday night, as the Full Moon occults Mars near opposition.

Have you checked out Mars lately? The Red Planet currently rides high to the east at dusk, rising as the Sun sets. We call this opposition season, the biannual span when Mars passes closest to the Earth and offers observers optimal views of the planet. Mars opposition 2022 is special however, as three events converge in one night: Mars at opposition, the Moon reaches Full, and the Moon occults (passes in front of) Mars, all on the evening/morning of Wednesday/Thursday, December 7th/8th.

Celestial Dates with Destiny

You can see how the action around Mars stacks up in the first week of December:

1st- Mars passes nearest Earth (2:00 Universal Time/UT)

8th-Full Moon (4:00 UT)

8th-Mars Lunar Occultation (4:00 UT)

8th-Mars at Opposition (5:00 UT)

Note that Mars is closest to the Earth a week prior to opposition. This occurs for two reasons: while the Earth is moving towards perihelion in January (that is, we’re moving towards the Sun in December, but away from Mars), the Red Planet is doing the opposite, headed towards aphelion on May 30, 2023, just under six months after this week’s opposition. This makes up for the 900,000-odd kilometer difference as Mars is 0.55 Astronomical Units (AU, or 81.5 million kilometers) from Earth on the 1st, but sits 82.4 million kilometers from Earth at opposition.

Mars from November 21st as it nears opposition. Image credit and copyright: Damian Peach.

In fact, we’re currently trending towards a cycle of unfavorable oppositions for Mars now, which will bottom out in February 2027 when Mars only reaches an apparent diameter of 13.8” as seen from the Earth. After 2027, Mars oppositions will slowly start to become more favorable again.

No Missions to Mars

Unfortunately, this Mars launch window also marks a sad milestone: for the first time since 2009, no mission will catch the biannual pre-opposition window to head to Mars. The European Space Agency’s ExoMars Rosalind Franklin rover was set to make the trip until Russia invaded Ukraine early this year, forcing ESA to look for another launch carrier and lander. ESA still hopes to get the rover to Mars by 2030.

The occultation visibility footprint for Wednesday night’s event. Credit: Occult 4.2.

‘Standing in the Shadow’ as the Moon occults Mars

But it’s Wednesday night’s occultation of Mars by the Full Moon that makes the 2022 opposition special. Opposition and the occultation plus the Full Moon all occur within an hour of each other. This is pretty rare: the near-Full Moon hasn’t occulted a naked eye planet or bright star since July 2019 (Saturn) and won’t do so again until May 24, 2024 (Antares), This is also the last of two occultations of Mars by the Moon for 2022, The Moon will occult Mars five times in 2023, though none are as favorable as the December’s event. The December ‘Long Night’s Moon’ nearest to the southward equinox also rides high in the sky for northern hemisphere observers, another plus.

Tuesday, December 6th at dusk, looking eastward. Credit: Stellarium.

This is also the closest Mars opposition versus a Full Moon with a lunar occultation for the 21st century. 21st century occultations of Mars near (less than 24 hours) from Full Moon also occur on December 24, 2007, January 14, 2025, February 5, 2042, May 28, 2048, February 27, 2059, and finally on April 27th 2078, which also features a shallow penumbral lunar eclipse.

The lunar occultation ‘footprint’ for Wednesday night’s occultation spans most of North America and Europe, with only the southeast U.S. missing out. Mars is 17” across during the event, shining at magnitude -1.9. The Moon will take just over half a minute to cover Mars during the occultation.

A sped up view of Wednesday night’s occultation event. Credit: Stellarium.

When to Watch

Here’s a table for select North American and European cities in the path of the occultation, with ingress/egress times. You can see an extensive list of sites and times here.

Detroit3:20UT/10:20PM EST4:09UT/11:09PM EST
Dallas2:54UT/8:54PM CST3:28UT/9:28PM CST
Los Angeles2:30UT/6:30PM PST3:30UT/7:30PM PST
Seattle2:51UT/6:51PM PST3:50UT/7:50PM PST
London5:00UT/5:00AM BST6:00UT/6:00 AM BST
Helsinki4:55UT/6:55AM EET5:39UT/7:39 AM EET
Table credit: Dave Dickinson.

Mars will be bright enough to follow riiiiiight up to the limb of the Full Moon during the event. The occultation occurs in the early morning hours for Europe on Thursday December 8th, and late in the evening of December 7th for North America. The disappearance of Mars behind the Moon will be visible even to the unaided eye, though binoculars or a small telescope will definitely help you enjoy the view.

Looking back from Mars, you’d be treated to an even stranger view, as the Moon transits the slim crescent Earth, just scant degrees from the Sun.

The Moon transits the Earth Wednesday night, as seen from Mars. Credit: Starry Night.

The Moon occults Mars: Weather Prospects, Watching Live

As of writing this, weather prospects for the contiguous United States (CONUS) look to favor the central northern states and the U.S. southwest.

Weather prospects across CONUS for Wednesday night’s occultation. Credit: NOAA.

Clouded out or simply live outside of the occultation footprint? Astronomer Gianluca Masi has you covered, with a live webcast as the Moon occults Mars, starting at 4:00 UT/11:00 PM EST Wednesday night.

Mars near the crescent Moon from 2020. Image credit and copyright: Efrain Morales Rivera.

The Moon Occults Mars: Spotting a ‘Daytime’ Red Planet

Finally… ever seen Mars in the daytime? It’s certainly possible near opposition… and the nearby Full Moon offers an excellent guide to complete this unusual feat of visual athletics. In North America, I’d start looking for Mars near the Moon just before local sunset, while in Europe, your best bet is to follow Mars near the Moon low to the West, after local sunrise.

Good luck, clear skies, and don’t miss this week’s unique, triple play dance of the Moon and Mars.

David Dickinson

David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe as he travels the world with his wife.

Recent Posts

Astronomers See a Black Hole Wake Up from its Ancient Slumber

Four years ago, the supermassive black hole hidden in the heart of galaxy SDSS1335+0728 roared…

4 hours ago

Venus is the Perfect Place to Count Meteors

Watching meteoroids enter the Earth’s atmosphere and streak across the sky as the visual spectacle…

23 hours ago

Do Protons Decay? The Answer Might be on the Moon

Does proton decay exist and how do we search for it? This is what a…

1 day ago

It’s Not Just Rocks, Scientists Want Samples Mars’s Atmosphere

Mars holds a very special place in our hearts. Chiefly because of all the other…

2 days ago

Something’s Always Been Off About the Crab Nebula. Webb Has Revealed Why!

The Crab Nebula has always fascinated me, albeit amazed me that it doesn’t look anything…

2 days ago

Lake Shorelines on Titan are Shaped by Methane Waves

Distant Titan is an oddball in the Solar System. Saturn's largest moon—and the second largest…

2 days ago