The interior of the Clark Telescope Dome, with Mars visible through the observation slit. Credit: Tom Polakis, Lowell Observatory Astronomer
Mars reaches full opposition on December 8, 2022, meaning that it will be at its biggest and brightest in our skies. In addition, the Moon will occult (pass in front of) extra-bright Mars the day before! Read on to learn more about these exciting astronomical events and how to view them from your own backyard.
☆ What is the Mars Opposition?
Opposition occurs when a planet is on the opposite side of the celestial sphere to the Sun, as
observed from Earth. During opposition, the planet in question is at its closest point to Earth in
its orbit and in its full phase. This makes the planet appear larger and brighter in the night sky
than usual, creating ideal observing conditions.
☆ How can I view the Mars Opposition?
Mars will be shining bright when it rises just after sunset (about 5:20pm MST), will be at its very
closest and brightest at 11pm MST on December 8, which will be the moment of maximum
opposition. Even if you miss totality, there’s no bad time to see Mars this month! As long as you
have a clear view of the night sky, you should be able to see the Red Planet in all its glory. After
sunset, look to the eastern horizon — if you see a very bright star with a reddish-orange glow,
you’ve found Mars!
Mars will get higher in the sky throughout the night, reaching its highest point at 12 midnight
local time. It will then move toward the west, where it will set just before sunrise. Mars will be at
its very closest and brightest at 11pm Arizona time on December 8, and will progressively grow
dimmer as it moves away from us in January.
☆ What is a Lunar Occultation?
A lunar occultation occurs when our planet’s Moon passes in front of a planet or a star, making it
disappear for a moment. The Moon occults the planets in our solar system several times a year,
but each occultation is visible from only a small portion of Earth’s surface at a time. The lunar
occultation of Mars on the evening December 7 will be visible for viewers everywhere outside
the East Coast and Southeast in the U.S. — this, in addition to the fact that Mars will be at its
biggest and brightest as it approaches opposition, makes it a particularly exciting observing
opportunity!
☆ How Can I View the Lunar Occultation of Mars?
The areas in which the Mars will seem to completely disappear behind the Moon will actually be
fairly narrow — to those situated in other areas along the occultation line, the Moon will appear
to just barely graze past the red planet (a event referred to as an appulse). To see if you live in
one of the areas where the occultation or the appulse will be visible, please refer to these handy
charts, courtesy of Space.com. Both events can be viewed with the unaided eye, but a telescope
or binoculars will add an exciting amount of detail to your observations.