This week offers multiple opportunities to get a great look at the Red Planet.
On Wednesday (Dec. 7), the full moon will be in close proximity to a bright Mars during an event known as a lunar occultation. And on Thursday (Dec. 8), Mars will be at opposition, meaning that in Earth‘s skies, it will be found directly opposite the sun. These events also happen to coincide with Mars being close to perigee (its closest point to Earth), which occurred on Nov. 30.
The perfect storm of astronomical events means that this is a wonderful week to watch Mars in the night sky, appearing larger and brighter than usual and making itself easy to spot next to a full Cold Moon. And even if you have cloudy skies or can’t make it outside, you’re still in luck: There are plenty of opportunities to see Mars at its best this week thanks to several free online livestreams.
How to see Mars in person this week
For many parts of North America, Europe and some parts of North Africa, the lunar occultation will be visible in the night sky on Dec. 7 and Dec. 8.
The spectacle begins roughly an hour after sunset in the Taurus constellation on Dec. 7 for North American skywatchers as the full moon and Mars move close together (in Europe, the event will happen just before sunrise on Dec. 8). Depending on one’s location, the Red Planet will then disappear behind the moon before reappearing an hour later.
Sky and Telescope has put together a guide on when and where you can see Mars (opens in new tab)disappear behind the moon this week during lunar occultation.
Griffith Observatory livestream of the lunar occultation of Mars
On Wednesday (Dec. 7), the Griffith Observatory in Los Angeles, California will host a free online livestream (opens in new tab) of the lunar occultation of Mars. The broadcast will begin at 9:00 p.m. EST (0200 GMT on Dec. 8), weather permitting. Mars will disappear behind the moon at 9:31 p.m. EST (0231 GMT) and reappear one hour later.
The observatory will also upload a time-lapse recording of the event on Thursday (Dec. 8) at 11:00 a.m. EST (1600 GMT).
McDonald Observatory livestream of Mars at opposition
The McDonald Observatory at the University of Texas at Austin, in conjunction with the Lowell Observatory in Arizona, will host a livestream of Mars at opposition. The broadcast begins on Thursday (Dec. 8) at 9:00 p.m. EST (0200 GMT on Dec. 9) and can be found on the McDonald Observatory’s YouTube channel (opens in new tab).
Hosts from both observatories will provide commentary during the event that will include discussions of Martian geology and history as well as spaceflight missions to the Red Planet. If weather permits, the livestream will include live views of Mars at opposition from telescopes at both observatory sites.
The Virtual Telescope Project livestream of the moon occulting Mars at opposition
The Virtual Telescope Project (opens in new tab) will host a free livestream of the moon occulting Mars at opposition. The broadcast will begin at 10:00 p.m. EST on Thursday (0300 GMT on Dec. 9) and can be found on the project’s YouTube channel (opens in new tab).
What does it mean when Mars is at opposition?
When astronomers say that a planet is at opposition, it means that the planet, Earth, and the sun are all in a straight line, with Earth in the middle. This arrangement means that the planet is literally opposite the sun, hence the term “opposition,” making the planet appear brightly lit from our vantage point on Earth.
When the Red Planet is in opposition, it is much brighter than usual and therefore much easier to see in the night sky. This event only happens every 26 months, and the planet’s elliptical orbit means during some oppositions Mars is closer to Earth than others.
During this week’s opposition, Mars will be closer to Earth than it will be until 2033. The Royal Astronomical Society has put together a great explainer (opens in new tab) on the event, including the video below.
What is a lunar occultation of Mars?
The word “occult” means to conceal or hide from view; when astronomers refer to an occultation, they mean an event in which one celestial object passes in front of another from an observer’s perspective, hiding the object behind it. In the case of this week’s lunar occultation of Mars, it means that from Earth, the moon will appear to conceal or “cover up” the Red Planet. For many viewers, Mars will disappear behind the moon for roughly an hour before reemerging into view.
There are enough occultations throughout any given year that there is an International Occultation Timing Association (opens in new tab) which provides detailed information such as exact locations and times of other occultations.
The Griffith Observatory has published a video explainer (opens in new tab) of the event, found below.
Read more: What is an occultation?
Whether you’re new to skywatching or have been it at for years, be sure not to miss our guides for the best binoculars and the best telescopes to view the occultation of Mars and other incredible things in the night sky. For capturing the best Mars or moon pictures you can, check out our recommendations for the best cameras for astrophotography and best lenses for astrophotography.
Editor’s Note: If you snap a great photo of either Mars at opposition or the lunar occultation and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to email@example.com.