In June, Venus, the brightest planet, will continue to dominate the western sky after sunset and move away from the Twin Stars of Gemini, Pollux and Castor. It will reach greatest elongation – 45 degrees – from the sun on June 4th. Mars, nearby, continues to fade in brightness as we race away from it in our orbit around the sun. Don’t miss Mars buzzing through the Beehive star cluster on June 1 and 2, 2023. Later in the month, the moon will sweep past these 2 inner planets on June 21 and 22. The red arrow shows Mars’ position along the ecliptic – or path of the sun, moon and planets (shown as a green line on our chart) – for the month of June. With the white arrow showing Venus’ path. Note how Venus and Mars get closer together over the month. On June 1st, the planets appear 10 degrees apart, and by month’s end they appear less than 4 degrees apart. Both planets are moving toward Regulus in Leo the Lion. Venus and Mars will set around midnight (your local time) at the beginning of June and around 11 p.m. at month’s end. Check out our video about Venus and Mars. Chart via John Jardine Goss/ EarthSky.
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 June 2023, Mars will be in the western evening sky. Mars will fade in brightness – to 1.7 magnitude – and now dimmer than 1st-magnitude stars. Yet, it still appears as one of the brightest stars in our sky. Mars will be passing through the famous Beehive star cluster on June 1 and 2. The moon will sweep past Mars on June 21 and 22. See the charts below. Constellations in June 2023: Mars crosses in front of the constellation Cancer then Leo later in 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 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.
June 1 and 2 evenings: Mars buzzes the Beehive
The Beehive star cluster in Cancer the Crab will get a visit from reddish Mars on June 1 and 2, 2023. Point your binoculars at the red planet to see the glittering background stars of the Beehive cluster. Bright Venus and the Twin Stars of Gemini, Pollux and Castor, are nearby. Read more about Mars and the Beehive here. Chart by John Jardine Goss/ EarthSky.
June 19 and 20 evenings: Moon near Venus, the twin stars and Mars
On the evenings of June 19 and 20, 2023, the waxing crescent moon will float near the twin stars of Gemini, Castor and Pollux. Even though the twin stars are easy to pick out as 2 bright stars very close together, you’ll notice they don’t look exactly alike. Castor shines with a bright white light. And Pollux is a bit brighter than Castor and appears golden in color. Also nearby will be brilliant Venus and the steady red light of Mars. They’ll be visible for a few hours after sunset. Chart via John Jardine Goss/ EarthSky.
June 21 evening: Moon, planets and stars on the solstice
June 21, 2023, is a notable date because it marks the June solstice, the 1st day of summer for the Northern Hemisphere and 1st day of winter for the Southern Hemisphere. 2023’s solstice will feature the waxing crescent moon glowing next to brilliant Venus with the much, much dimmer Mars nearby. Above them will be the bright star Regulus in Leo the Lion. And below them will be the twin stars, Castor and Pollux, in the constellation Gemini. Look low in the west shortly after sunset for this beautiful scene in the darkening twilight. Chart by John Jardine Goss/ EarthSky.
June 22 and 23 evenings: Moon near Venus, Mars and the Sickle
The waxing crescent moon will glow near the planets Venus and Mars, plus the bright star Regulus in Leo the Lion, on the evenings of June 22 and 23, 2023. It will also lie near the dim star pattern – or asterism – known as the Sickle. You can catch the moon and the Sickle until around midnight. Chart via John Jardine Goss/ EarthSky.
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.
The geometry of Mars’ orbit is such that it spends much longer periods of time at large distances from the Earth than it does close to us, which provides added incentive to observe it in the weeks around opposition. When it passes opposition, every 2 years, Mars appears large and bright for only a few weeks. The panel above shows the month-by-month change in Mars’ apparent size from October 13, 2022, to February 2, 2023. Mars appeared 17 arcseconds wide on December 8, 2022. It’ll be 5.4 arcseconds on May 1, 2023. Image via Dominic Ford/ In-The-Sky.org. Used with permission.
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.
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.
Mars isn’t very big, so its brightness – when it is bright – isn’t due to its bigness, as is true of Jupiter. Mars’ brightness, or lack of brightness, is all about how close we are to the Red Planet. It’s all about where Earth and Mars are, relative to each other, in their respective orbits around the sun. Image via NASA.
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.
There’s a 15-year cycle of Mars, whereby the Red Planet is brighter and fainter at opposition. In July 2018, we were at the peak of the 2-year cycle – and the peak of the 15-year cycle – and Mars was very, very bright! In 2020, we were also at the peak of the 2-year cycle; however, Earth and Mars were farther apart at Mars’ opposition than they were in 2018. Still, 2020’s opposition of Mars was excellent. So, in December 2022, Mars had a good opposition but appeared smaller and dimmer than in 2020, since we were farther away from it. Diagram by Roy L. Bishop. Copyright Royal Astronomical Society of Canada. Used with permission. Visit the RASC eStore to purchase the Observer’s Handbook, a necessary tool for all skywatchers.View at EarthSky Community Photos. | Miguel Ventura in Fafe, Portugal, captured this image on August 28, 2022, and wrote: “Every now and then and in addition to its natural beauty, the night sky and the whims of the universe offer us moments like this. With some planning and luck in the mix (truce from the clouds) I was able to photograph this magnificent alignment. We can see the Pleiades and the constellation of Taurus with the planet Mars between these 2 … below near the horizon the imposing constellation of Orion appears, announcing the autumn sky.” Thank you, Miguel!
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 June 2023 here.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.
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