Over these past months, the planets Mars and Saturn – along with the star Antares in the constellation Scorpius – have made a prominent triangle on our sky’s dome. But then Mars began moving with respect to the star background, shifting rapidly eastward. It’s passing in between Saturn and Antares this week, around August 23 and 24, so that the three objects appear in a straight line in our sky. Very fun to see!
Enjoy these photos from the EarthSky community. The newer ones are closer to the top of the page. And remember that Mars and Saturn are planets, while Antares is a star. Right now, Mars is about 7 light-minutes from Earth (79 million miles, or 127 million km). Saturn is about 82 light-minutes (914 million miles, or 1,470 million km). Antares – being a star, and not an object in our own solar system – is vastly farther away at about 550 light-years.
After the Mars-Saturn conjunction on August 24, be sure to keep an eye on this trio of objects as darkness falls each night. Mars will travel farther and farther east of Saturn and Antares.
Before they were a line, they were a triangle. The photos below are in descending order, chronologically. If you look at them from the bottom up, you can see Mars get closer to the line between Antares and Saturn, and finally pass between them!
By the way, three other planets – Jupiter, Mercury and Venus – are also up after sunset. If you see them, you’ll be seeing all five planets visible to the unaided eye from Earth. Look soon, though. Mercury will soon disappear, especially as seen from Northern Hemisphere skies (it’ll stay visible a few more week’s from Earth’s Southern Hemisphere).
Meanwhile, Jupiter and Venus are about to have a spectacular conjunction! It’ll come on August 27. Read more about the Jupiter-Venus conjunction, check out the chart below … and check back at this link later for more photos and details.
Bottom line: Mars has been moving in between Saturn and the star Antares n the sky’s dome. On August 23 and 24, these three shining objects will make a nearly straight line on our sky’s dome. Then mark your calendar for August 27, when Jupiter and Venus – the sky’s two brightest planets – will be in conjunction.
Deborah Byrd created the EarthSky radio series in 1991 and 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.