Will We See A Redder Red Spot On Jupiter This Season?

Look for Jupiter in Gemini to the right of Orion in the eastern sky at dawn. Stellarium

Jupiter’s catching the attention of morning skywatchers. It rises around 2 a.m. and shines at a comfortable height in Gemini at the start of dawn. You can’t miss it. Just face east – it’s the brightest planet visible at that hour.

Jupiter on Aug. 21 photographed by Damian Peach. The Great Red Spot is visible at lower right. The black dot is the shadow of the moon Ganymede on Jupiter’s cloud tops. Credit: Damian Peach

Recently, astrophotographer Damien Peach shot a picture of the giant planet through his telescope that shows the classic dual “tire track” stripes across the globe called the North and South Equatorial Belts. His photo is one of the best taken so far during the new observing season. It clearly shows the Great Red Spot (GRS), an enormous high-pressure hurricane-like storm that’s persisted for centuries in Jupiter’s southern hemisphere.

The most amazing thing about this tempest is how big the thing is. Although its diameter fluctuates, the GRS is currently about 2 1/2 times the size of Earth.

Earth vs. the Great Red Spot comparison. The GRS is about 20,000 miles across. Credit: NASA

Whenever people want a look at Jupiter through my telescope, they’ll invariably ask if they can see the Great Red Spot. Even when it’s out on the front side of the planet however, it’s notoriously hard to see. Over at least the past decade the GRS’s color has been closer to pale pink than red. Because of low contrast compared to the surrounding clouds, the spot takes an effort to see.

That might be changing. Peach added this observation along with the photo:

“The GRS is notably darkened in colour from last apparition – this was also easily apparent visually at 340x.”

News of the spot’s darkening is most welcome. When I was a teen, the GRS stood out a bold red-orange; anyone looking through my little 6-inch reflector could see it. As Jupiter rises higher in the sky and becomes easier to view at a more convenient hour, let’s hope we’re in for a redder red spot this season.

5 Responses

  1. Edward M. Boll

    Jupiter may almost be easier to see than Venus now. I was surprised at how early Venus sets now. Of course, Fall is not a good time for evening planets. I have seen Venus at midnight in April. There are only 2 objects brighter than Venus, the Sun and Moon. Except on Jan. 12, 2007 I could clearly see that Comet McNaught was brighter than Venus. If ISON gets that bright, and the sky is clear, I will be looking at Comet ISON after sunrise on Thanksgiving Morning. Proper eye care will be necessary.

  2. les

    hi i was curious to know if you could explain what that blue light near the sun is..i guess it only shows sometimes… someone posted a picture on fb of it and was curious to know if its something strange or something you know of. thanks

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