We have our best views of Mars only once every 2 years. And that time is fast approaching! Watch a replay of our livestream for more information about Mars.
- Mars can appear bright or faint in our sky. 2024 has been mostly a faint year, but Mars has been steadily brightening, and it’s very noticeable now, nearly as bright as the sky’s brightest star. The time to start observing Mars for this two-year period is here.
- Mars is growing brighter as Earth catches up with Mars, in our smaller, faster orbit around the sun. The coming opposition of Mars – when Earth will pass between it and the sun, bringing Mars closest and brightest – will take place on January 15-16, 2025.
- Start watching for Mars now. It’s up in the east by late evening, following blazing Jupiter across the sky.
Mars in 2024
Opposition for Mars last fell on December 7-8, 2022. That’s when our planet Earth last flew between Mars and the sun. Mars will reach opposition again at 3 UTC on January 16, 2025. Throughout November 2024, Mars has been growing brighter. It’s now easy to spot late at night through dawn.
Mars will be closest to Earth at 14 UTC on January 12, 2025. It’ll be 5.3 light-minutes away at a distance of 0.642 astronomical units (59,703,891 miles or 96,084,099 kilometers).
How to see Mars in the sky: Mars is now nearly as bright as Sirius, the sky’s brightest star. It was near the moon on December 17, 2024. Mars, Jupiter and Sirius will appear as “New Year’s stars” on December 31.
Note: Mars reaches opposition about every 26 months, or about every two Earth years. It’s now racing toward its January 15-16, 2025, opposition. Wait. That’s not quite right. It’s Earth that’s racing up behind Mars, in our smaller, faster orbit around the sun.
Mars in December 2024
Sometimes, Mars is faint
Mars last reached opposition on December 8, 2022. It remained bright through early 2023, then started to rapidly fade through the end of the year. Mars reached superior conjunction – when it passed behind the sun as viewed from Earth – on November 18, 2023. It began 2024 as a faint object, far across the solar system from us. But now Mars is getting bright again.
Sometimes, Mars is bright
Mars’ dramatic swings in brightness (and its red color) are why the early stargazers named Mars for their god of war.
Sometimes the war god rests. And sometimes he grows fierce! These changes are part of the reason Mars is so fascinating to watch in the night sky.
Want to follow Mars? Bookmark EarthSky’s monthly night sky guide.
Mars isn’t very big
To understand why Mars varies so much in brightness in Earth’s sky, first realize that it isn’t a very big world. It’s only 4,219 miles (6,790 km) in diameter, making it only slightly more than half Earth’s size (7,922 miles or 12,750 km in diameter).
On the other hand, consider Mars in contrast to Jupiter, the biggest planet in our solar system. Jupiter is 86,881 miles (140,000 km) in diameter. As an illustration, more than 20 planets the size of Mars could be lined up side by side in front of Jupiter. Basically, Jupiter always looks bright, because it’s so big.
Not so for little Mars, however. Rather, its extremes in brightness have to do with its nearness (or lack of nearness) to Earth.
Future Martian oppositions
As mentioned above, the next opposition of Mars – when will appear at its brightest in Earth’s sky for that two-year period – will be January 2025. Check out the chart at C. Seligman’s Mars oppositions page that lists all oppositions of Mars from 1995 to 2037.
EarthSky Community Photos
Seeing red
Mars appears as a reddish light in the sky and, therefore, is often called the red planet. Other obvious red dots in the sky are reddish-orange Aldebaran and the famous red supergiant Betelgeuse. So, it is fun to contrast Mars’ color and intensity of red with that of Aldebaran or Betelgeuse.
And then there is red Antares. Antares is Greek for rival of Ares (Ares being the Greek name for Mars). Antares is sometimes said to be the anti-Mars due to its competing red color. For a few months every couple of years Mars is much brighter than Antares. Also, every couple of years Mars passes near Antares, as if taunting the star. Mars moves rapidly through the heavens and Antares is fixed to the starry firmament.
What makes them red?
Surface temperature is what determines the colors of the stars. The hottest stars are blue and the coolest stars are red. In fact, from hottest to coolest, the colors of stars range from blue, white, yellow, orange and red. And while the colors of stars might be hard to detect, some stars – like Aldebaran, Antares and Betelgeuse – are noticeably colorful.
On the other hand, Mars appears red for a different reason. It’s red because of iron oxide in the dust that covers this desert world. Iron oxide gives rust and blood its red color. Rovers on Mars sampled the Martian dust and determined it contains three colors: reds, browns and oranges. So those three colors are what you may see when you gaze upon Mars.
Do you see red when you look at Mars, Aldebaran, Antares and Betelgeuse? Are they the same color? Do you see any other colors of stars?
Bottom line: Mars was the bright red “star” near last night’s moon. Earth is racing up behind Mars in orbit now, about to catch up with it, bringing Mars to opposition in January 2025.
Moon and Mars! Fav photos of December 7 occultation
Photos of bright Mars in 2018, from the EarthSky community
Photos of bright Mars in 2020, from the EarthSky community