Parade! Parade! How to see the Feb. 28 ultra-rare six-planet show

On the evening of Saturday, Feb. 28, a rare “planetary parade” will form in the western sky as six of the solar system’s planets appear together shortly after sunset, offering stargazers, students and the public a striking celestial show. 

Mercury, Venus, Jupiter, Saturn, Uranus and Neptune will form an arc across the horizon, an alignment caused not by literal straight-line ordering in space but by their positions along Earth’s line of sight. The event provides a vivid reminder of the dynamic nature of our solar neighborhood and an accessible opportunity for skywatchers to connect with astronomy.   

SDSU NewsCenter’s Zoe Glotzer asked Douglas Leonard, a professor in the San Diego State University Department of Astronomy, to explain the science behind this celestial spectacle and what makes this alignment in the sky special, how to view it, and another reason to look up this Tuesday, March 3. 

What exactly is a planetary parade, and what makes the Feb. 28 event special compared with an ordinary night sky?

A planetary parade is a popular term that simply means a whole bunch of the planets are all above the horizon and in our night sky at the same time. Not including the Earth, there are seven major planets in our solar system; on a typical night, perhaps three will be above the horizon and in our sky at any point during the night.

When four or five or more are there, people start calling it a parade, and the more there are, the more rare the event becomes. Currently, there are six above our horizon for a short time after sunset, making it a quite rare parade. This Saturday, Feb. 28, represents the best day to see it, although any day within about a week of Feb. 28 is also fine.

From your perspective, what should observers know before they look up on the evening of the parade — from timing to visibility challenges — so they don’t miss the show?

Well, they should know that, while interesting to look at, nothing dramatic will be happening on Feb. 28; planets move quite slowly night to night, and this particular alignment will still be visible for the next several days afterwards, although it gets trickier to see as the days go by. In fact, on Feb. 28, several of the planets will be tough to see since they will be setting very shortly after the Sun sets.

Basically, for the best bet at seeing the most planets, you want to be in a nice, dark location with a very clear western horizon. When the sun sets in the west, at about 5:45 p.m., let about a half hour go by so that the sky darkens enough, and then look hard again toward that western horizon. Clustered in a little group will be three stars. They are the planets Mercury, Venus and Saturn. Since they are very close to the horizon, though, they will be tough to see. Most likely, you will just see the brightest one, which is Venus. 

Then look nearly straight up, and that very bright star you see nearly directly overhead is Jupiter. Nearby you will also see the moon. Rounding things out, Uranus and Neptune are also up, but you will need binoculars or, better, a telescope to see them as they are too faint to see with the naked eye. So, bottom line, of the six planets that are up, you most likely will be able to spot two or three!

Why do planetary parades happen, and what does this celestial choreography tell us about the nature of our solar system?

As we have known since the time of Copernicus in 1543, all planets orbit the Sun, and they do so with different speeds and periods. The time it takes to go once around ranges from 88 days for Mercury to 165 years for Neptune. They also orbit the Sun in very nearly the same plane. This means that the particular planets that will be in our nighttime sky changes a lot over time.

Only once in a while will five or more be there all at once. That is what makes this six-planet event quite unusual. The next time this many planets will all be above the horizon at the same time during the night will not be until 2034, when all seven will be there, although several will be very tough to see, as they will be very close to the horizon.

Fun fact: If you can spot Venus, Jupiter and the moon on Feb. 28, you will see that you can draw roughly a line in the sky connecting them. This is telling you that all of these objects orbit in nearly the same plane as the Earth orbits the Sun.

In your experience, what is the most surprising or awe-inspiring thing about these kinds of astronomical events?

I think it's just that it gets regular folks to look up and perhaps think about their place in the universe for a moment, and also appreciate the cosmic dance that occurs above us every day.

What other celestial events should skywatchers be on the lookout for this week?

Glad you asked: a total lunar eclipse next Tuesday morning, March 3. This is a truly spectacular event. Starting at 1:50 a.m., the shadow of the Earth will begin passing over the full moon, completely covering it at 3:04 a.m. The moon will remain fully covered by the shadow but will actually glow a deep crimson red or orange due to some light reflecting off its surface after being filtered through Earth’s atmosphere, until 4:02 a.m., at which point it begins to get uncovered once more. The eclipse then ends at 5:17 a.m. 

I know people may be reluctant to stay up or wake up to see it, but lunar eclipses are awesome and well worth losing a little sleep for, especially if you have never seen one. The next one in San Diego after this isn't until June 25, 2029!