Utah Skies: Mars Passes The Pleiades

Mar 10, 2021

Credit Tom Westre

The most famous of all star clusters is the Pleiades Cluster, better known as the Seven Sisters. This beautiful group of stars lies in the constellation Taurus the Bull.

To the casual observer, the Pleiades appear as a tight formation of 6 or 7 stars in the shape of a little dipper. However, under dark sky conditions, observers have reported as many as 11. In fact, the cluster contains hundreds of stars. The cluster lies at a distance of 425 light-years. Compared to our Sun the stars that form the Pleiades are only 100 million years old.

The stars are surrounded by a faint nebulosity that appears blue in long photographic exposures. The nebulosity is seen by reflected starlight from the cluster members. Alcyone is the central star of the group and the brightest member. It’s 10 times the size of the Sun.

The cluster has been observed since ancient times. They are named after Greek mythology. But most ancient cultures have mythologies about the Pleiades.

The Native American legend of the Pleiades includes the Devil’s Tower in Wyoming. To the Kiowa, the Tower was placed there to protect seven Indian maidens pursued by giant bears. Later they were placed in the sky as the Pleiades star cluster by the Great Spirit. The striations on the sides of the Tower are said to be made by the bears’ claws.


As the planet Mars orbits the Sun it moves along the ecliptic, the path the planets follow. On March 3 Mars was closest to the Pleaides and won’t get this close until 2038.


If you go out in the early evening Mars and the Pleiades are high up in the western sky. The Pleiades are just to the right of Mars. The cluster should be visible until later in April.