Mars sometimes appears bright in our sky and sometimes appears faint. In early 2023, Mars appeared as bright as the sky’s brightest stars. Mars had disappeared from our view in October 2023, … it was close to the sun. And it won’t be back until next year when it will appear in the morning sky.
Mars in 2023
Opposition for Mars last fell on December 8, 2022. That’s when our planet Earth last flew between Mars and the sun. As 2023 began, Mars was still bright. By September 2023 Mars had faded and was difficult to catch in the evening twilight. Mars will reach opposition again in January 2025.
How to see Mars in the sky: In December 2023, Mars is too close to the sun to see. It reached solar conjunction at 6 UTC on November 18.
Constellations in December 2023: If we could see Mars, it would be crossing in front of the constellation Scorpius this month. And then, Mars moves in front of the constellation Ophiuchus and Sagittarius by the end of the month.
Note: Mars reaches opposition only about every 26 months, or about every two Earth-years. So Mars alternates between appearing bright and faint in our sky. It was bright in late 2022 and early 2023. But by September 2023, Mars faded dramatically in brightness and disappeared in the sunset glare in October 2023. It’ll pass behind the sun on November 18. It’ll come back into view, in the east before sunrise, in early 2024.
Sometimes, Mars is faint
Mars was in our evening sky for much of 2021. But, around October, the red planet disappeared from our sky for a time. Its superior conjunction – when it was most directly behind the sun as seen from Earth – was October 8, 2021. Then, some weeks afterwards – as both Earth and Mars moved in their respective orbits around the sun – Mars returned to our sky as a faint red dot in the east before sunrise. To be sure, it remained inconspicuous throughout the early months of 2022.
Sometimes, Mars is bright
Mars steadily brightened in the first half of 2022, first as a morning object. But later, during the second half of 2022, Mars shone as a bright red ruby in the evening sky. Ultimately, it reached opposition – when Earth flew between Mars and the sun – on December 8, 2022.
Indeed, 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! In fact, 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 Mars isn’t a very big world. Indeed, 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
So, when is the next opposition of Mars? The next time Mars will appear at its brightest for that two-year period in our sky? You guessed it. In January 2025! Check out the chart on this page that lists all oppositions of Mars from 1995 to 2037.
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 compare 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, meaning rival of 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 is no longer visible in our night sky. It is too close to the sun to see for the rest of 2023. It’ll return in January 2024 as a light in our morning sky.
Moon and Mars! Fav photos of December 7 occultation
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