If you think you’ve been seeing more planets shining brighter in the sky than usual for the last month and a half, you’re right.
An astronomical phenomenon known as a “planetary parade”—where multiple planets align in the same region—is currently shaping Gainesville and all northern hemisphere skies. While planetary parades are relatively common with four to five planets lining up, this parade involves all seven planets, with Venus, Mars, Jupiter and Saturn visible to the naked eye.
Although the occurrence climaxed on Jan. 21 with a conjunction—close alignment—of Saturn and Mercury, the planetary parade will culminate on Feb. 28 when all the planets line up. This month’s parade with all seven planets lining up will be the last one for the next 15 years when Saturn and Jupiter are back on the same side of the sky in 2040.
“This is an opportunity for us to encourage people to go outside and look up,” said James Albury, Santa Fe College’s Kika Silva Pla planetarium’s manager. “Most people don’t look up from their cell phones, or they’re busy doing their usual thing in the evening. We astronomers and other science communicators are saying, ‘hey, go outside and look up and you’ll see the planets.’”
Albury said the image of aligning planets as seen from Earth during a planetary parade depends on where Earth is in the solar system compared to the other planets as the Earth rotates, as well as the retrograde of the planets.
Retrograde is when a planet following its typical line of orbit from west to east appears to slow down, travel in the opposite direction and shine brighter. Albury said that figuring out how and why planets move the way they do in retrograde to create formations like planetary parades has evolved over time.
Early explanations started with ancient peoples and astrologers associating the movement of planets with the temperament of their gods. A geocentric—or earth-centered—model of the universe also made it challenging to get to the scientific root.
But once astronomer Nicolaus Copernicus discovered the heliocentric—or sun-centered—model of the universe in 1543, and Johannes Kepler found elliptical orbits of planets around the sun in 1609, the difference in planet speeds explained retrograde.
“It’s like when you’re driving in a car on I-75 and you’re going faster than the car next to you,” Albury said. “Even though you’re both going the same direction, that car looks like it’s going backwards with respect to the background. That’s what’s happening with the planets. Because we’re going faster than Mars and we just passed Mars in our orbit, Mars looks like it’s going backwards against the stars. Eventually, as we start to go around the bend, Mars is going to look like it’s going forwards again.”
While Mars is typically “misanthropic” and isolated from the other visible planets, Albury said it is especially bright right now during the parade of planets because it’s in retrograde and coming back around the sun.
Mercury is also coming into the evening sky after being in the morning sky for the last two months, and Venus can be seen during the daytime as a white dot next to the moon.
Dr. Paul Sell is an associate instructional professor and astronomy undergraduate coordinator at UF. He said that the brightness of the planets right now is just as special to see as their rare alignment.
“Currently, Venus and Jupiter are brighter than any star and Mars is brighter than almost any star, making them stand out quite clearly even from the light-polluted skies of the city,” Sell said.
To view the parade of planets, Albury said viewers only need to look up. Planets can be distinguished from stars because they have a steady light instead of one that appears to twinkle. Twilight or around 6:30 p.m. after the sun sets are the best times to see the alignment and star-tracking apps can also be downloaded for free to help identify any celestial bodies.
Albury runs weekly star shows at 7 p.m. on Fridays at the Kika Silva Pla planetarium (3000 NW 83 St., building X-129). During the Feb. 21 show, he said he will discuss the current parade of planets and take the telescope out for viewers to look through if the sky is clear.