Mars sometimes appears bright in our sky and sometimes appears faint. In early 2023, Mars appeared as bright as the sky’s brightest stars. By June 2023, Mars will start to fade dramatically in brightness and appear close to the sunset. By October, November and December, 2023, Mars will be lost from our view … behind the sun.
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. But it’s fading now – and appearing in the sky for fewer hours of the night – as Earth races ahead in our smaller, faster orbit around the sun.
How to see Mars in the sky: In April and May 2023, Mars will be in the western evening sky. Mars has faded in brightness and now blends in with the other 1st-magnitude stars. That is, it still appears as one of the brightest stars in our sky. The moon will sweep past Mars on May 24. Mars will be edging toward the famous Beehive star cluster. See the charts below.
Constellations in April and May 2023: Mars is in front of the constellation Gemini this month. It’ll cross the border between Gemini and Cancer in mid-May.
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 about June 2023, Mars will start to fade dramatically in brightness. It’ll disappear in the sunset glare around 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.
First part of May: Mars in Gemini
May 22-23 evenings: Moon will pass Venus, Castor, Pollux and Mars
May 24 evening: Moon will visit Mars and the Beehive
View from above the solar system, April and May 2023
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.
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 and Betelgeuse – are noticeably colorful.
Iron oxide
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 and Betelgeuse? Are they the same color? Do you see any other colors of stars?
Bottom line: Mars is still bright, but it’s destined to fade in brightness and appear for fewer hours of the night … See Mars while you can! Charts for April and May 2023 here.
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
