How to Watch This Week's 'Planetary Parade'

Featured on many classroom walls is a poster of our solar system. On most, the planets appear aligned in a tidy row. That doesn’t often happen. But one such “planetary parade” starting Monday will prove the posters right, at least for a little while. 

In the early morning hours of June 3, Jupiter, Mercury, Uranus, Mars, Neptune, and Saturn, in that order, will all form a line in the eastern sky. Most will be hard to see. But stargazers with strong telescopes will be able to track them as a left-to-right diagonal line. The waning crescent moon will be in the middle of it. Those hoping to spot the phenomenon with the naked eye will have to contend with a powerful intruder seeking to spoil the show, though.    

“The sun’s going to be photobombing the parade,” Ronald Gamble told The Associated Press. He's a scientist at NASA's Goddard Space Flight Center.

Still, at least two planets will be viewable: Mars as a tiny red dot and Saturn as a faint yellowish sphere. And later in the week, the moon will clear out of the way. That should make nighttime viewing slightly more rewarding. 

To understand why the planets seem to “line up” in the first place requires a dive into the Ecliptic. That's the path the sun takes across the sky each year. All the planets of our solar system are on the same general plane as they orbit the sun. And while they move at different speeds, they sometimes sync up along the Ecliptic. It happens more often than you might think. That's especially true with 6 of the 8 planets. Getting all 7 (plus Earth) in a line in the sky is more rare. That won’t happen again until February 28, 2025.     

Reflect: Why do you think people get excited about special events in the sky, like seeing planets line up?