Mars looks like it’s about to make a U-turn in the night sky – at least, from Earth it looks that way.
Since Dec. 7, 2024, the red planet has been making its westerly retrograde. But on Monday, that all ends, according to Space.com. Mars will appear to stand still in the night sky before it makes its regular eastward retrograde orbit through the solar system.
Retrograde is the backward movement relative to its usual direction, according to NASA. But this cosmic U-turn is from Earth’s perspective. Its stop and turnaround in its orbit is because Earth is passing Mars at a faster rate of speed.
On average, Mars goes into retrograde every 26 months, according to BBC Science Focus.
Mars moves at a slower speed than Earth, at an average speed of 53,979 mph, according to Cool Cosmos, an astronomy website run by NASA and its frequent partner the California Institute of Technology, or Caltech. In contrast, Earth moves around the sun at 67,100 mph.
With one planet moving faster than the other, Mars’ brightness will descend from magnitude -1 to -0.3, with its size through a telescope also shrinking slightly, Space.com reported.
A celestial object’s stellar magnitude describes how bright that object looks in the night sky, with the brightest stars being seen at a magnitude of 1, EarthSky reported. Objects with a negative magnitude appear much brighter without the need for a telescope, according to NASA.
Despite its diminished brightness, Mars will still be visible in the night sky, weather pending. And it will take part in the upcoming planetary parade on Feb. 28, co-starring with Saturn, Mercury, Neptune, Venus, Uranus and Jupiter.
Mars, the fourth planet from the sun, is situated between Earth and the asteroid belt. It has a radius of 2,106 miles and is about half the size of Earth, according to NASA. Mars is 1.5 astronomical units away from the sun, with one astronomical unit being the distance between the sun and Earth.
Within the inner solar system, Mars has the most moons – but a far cry from Saturn’s 146, the most of any planet in the solar system.
These moons, Phobos and Deimos, are believed to be either asteroids captured by Mars’ gravity or debris from the early formation of the solar system, according to NASA. Phobos and Deimos, Greek for “fear” and “dread,” were named by American astronomer Asaph Hall in 1877. Hall named them after the sons of Ares, the Roman god of war and the counterpart to the Greek god Mars.
