Jupiter Closest To Earth In 47 Years

Jupiter shines in a moonlit sky last night around 9 p.m. Look to the southeast to find it. Details: 20mm lens at f/2.8, ISO 800 and 25-second exposure. Photo: Bob King

Tonight Jupiter is at opposition and shines more brightly now than at anytime this year. Go out and get an eyeful while it’s so close to Earth. Opposition means opposite the sun, and that’s exactly where the planet will be – when the sun retires in the west this evening, Jupiter will rise 180 degrees opposite in the eastern sky. The king of the planets stays up all night long, inviting sky watchers of all kinds to marvel at his radiance.

Jupiter is located under the Square of Pegasus in the dim constellation Pisces, but you don’t really need a constellation to point you to it. The stars of Pisces and its neighbors can’t hold a candle to Jupiter’s brilliance, which is one the reasons the planet dazzles in the southeast after 9 o’clock. No competition means Jupiter rules.

Once a year, Earth and Jupiter line up on the same side of the sun, when they're closest for the year, an event astronomers call opposition. After tonight, Earth's motion will break the lineup and the distance will slowly increase between the two planets. Illustration: Bob King

When a planet’s at opposition, it lines up with Earth on the same side of the sun. All the outer planets from Jupiter to Neptune reach opposition once a year when the speedier Earth laps the slower-orbiting outer planet. Oh, and there’s Mars. Because it’s the closest outer planet and moves relatively quickly, it takes Earth a while longer to catch up and finally pass the planet; Mars oppositions occur about once every two years.

Planets orbit in ellipses with the sun off to one side. Perihelion is when a planet is closest to the sun; aphelion when farthest. Illustration: Bob King

This particular Jupiter opposition is the closest since 1963 for one very good reason – Jupiter is close to perihelion. Let me explain. All the planets revolve about the sun in ellipses (ovals) rather than perfect circles. This means their distances from the sun vary over time as they curve around one end of the ellipse and then back over to the other. Earth’s elliptical orbit brings it 3 million miles closer to the sun in January than in July. Jupiter takes 12 years to orbit the sun. During that time its distance varies from 461 million miles to 507 million, a difference of 46 million miles from one end of the ellipse to the other.

Jupiter's most prominent belts and regions are seen in this photo taken on September 18. Most of these features are visible in 4.5" and larger telescopes at around 100-150x. The North Equatorial Belt is easiest. Credit: Anthony Wesley

When a planet is closest to the sun, it’s said to reach perihelion. Earth is at perihelion once a year in January. Jupiter reaches perihelion once every Jupiter year which is equal to 12 Earth years.

Turns out, Jupiter’s perihelion is coming up very soon – next March as a matter of fact.  Tonight’s opposition happens to nearly coincide with Jupiter’s perihelion (closest approach to the sun), which means it’s especially close to the Earth. Next year, when Earth swings between Jupiter and the sun again, Jupiter will have moved past perihelion and be a smidge farther away than it is tonight.

“I Saw Her Standing There” from Please, Please Me

1963 seems like a long time ago. That was the year the Beatles released their debut album “Please, Please Me”, zip codes were first introduced in the U.S. and Martin Luther King delivered his “I Have a Dream” speech. Jupiter was in Pisces back then, too, and will when it’s close again in 2022.

A close approach like this one means the planet appears larger than usual and brighter as well. If you own a telescope, this year will be one of the best of the next 12 years to study the planet. And don’t fret if it’s cloudy tonight. Jupiter will appear nearly as bright and large well into the fall. If you’re an early evening sky watcher, look to the southeast, but if you’re out around bar closing, the planet will be high in the south.  In the wee hours before dawn, it drops off into the southwestern sky.

2022? I hope to be alive then, but just in case, I plan to scrutinize the face of the mighty planet at every opportunity this season.

9 Responses

    1. astrobob

      Hi Tina – Yes it is! Although Jupiter’s in the southeast around 9-midnight, by 1 a.m. it’s due south and before dawn, it’s moved into the southwestern sky. It’s up all night right now.

      1. Awesome! That’s been sticking out to me every morning! Guess it’s time to grab the telescope (tell-a-soap as my daughter likes to call it) and go take a peek! 😀

  1. Nice Image Bob! I am the new photographer for the Mitchell Daily Republic and have tried my hand at a few star images and time lapses but that is a truley stunning image of jupiter great work. Thanks for the tip on jupiter I look forward to seeing it in all its glory tonight.

    1. astrobob

      Thanks for the kind words Chris. If you get something nice you’d like to share, please send it along and I’ll try to post it in the blog.

  2. Jim Morrison

    Thanks for the information on Jupiter. I have been interested in the planets since I was small and read science fiction stories about aliens living in our solar system. Although the chance of that now appears small, I’m still fascinated by the thought.

  3. Wow! Just found you and really enjoyed reading about our planets. Just a novice.. Was outside tonite (Crosslake, MN) (hi, Duluth)! and had to find out what that beautiful sparkly thing was. And now I know! Thanks, Page
    Do you have a website?

    1. astrobob

      Hi Page, welcome aboard! I don’t have a separate website – just the blog. Glad you found Jupiter. I just got back in from looking at it myself. — Bob

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