Jupiter and the Great Red Spot


Yay finally got the Great Red Spot!  Throughout the years observing and taking photos Jupiter, I’ve always wondered if the darker detail I was observing was the Great Red Spot.  Based on date and time it’s possible to determine if the GRS is in view, plenty of software and tables out there for that.  But now I’ve captured my first picture of Jupiter where the GSR is unmistakable, 672 million km away.

Jupiter and the Great Red Spot

Jupiter and the Great Red Spot – March 27th, 2016

April is prime Jupiter observing time, as Jupiter reaches the meridian just before midnight.  And we happen to be at time when the Earth-Jupiter distance is at its shortest, so don’t miss out!  As it’s high in the sky, there is less turbulent atmosphere to peer through and the seeing is better.

Jupiter at 10pm mid-April

Jupiter at 10pm mid-April

The chart above is the sky due south at 10pm local time on April 15th.  And if you have a set of binoculars, camera zoom lens or telescope you’ll easily be able to see four of Jupiter’s moons all lined up next to the planet.

Above photo of Jupiter:
Skywatcher 80ED with Televue 3x
Philips Vesta 675 webcam (yes it’s old…)
Registax for alignment and wavelet
Gimp for post-processing

Jupiter’s Great Red Spot – Could it be gone in 20 years?

One of the great targets for backyard astronomers is Jupiter, and spotting its moons, the cloud bands and the Great Red Spot is always a treat. Observations over a few days provides a good view into the dynamic nature of the clouds and the orbits of the Moon.  I haven’t yet managed to capture the Great Red Spot on photo, but maybe this fall as Jupiter comes back into view in the evening sky, I should make the effort to spot the GRS.  This is because ever since it’s discovery in the 1800s, it has been shrinking in size.  And at the current rate, it could be gone all together in as little as 20 years!

Jupiter's Great Red Spot (1995 and 2014) - NASA

Jupiter’s Great Red Spot (1995 and 2014) – NASA

In the last 10 years it has shrunk by 3000km, taken a more circular form and increased its rotational speed.  Amateur observations since 2012 have revealed that this phenomenon is even accelerating, shrinking by as much as 930km per year.  Current measurements have the GSR now pegged at under 15,000km in diameter.

As we head into the fall, Jupiter will become easier to observe.  By December Jupiter will be high in the sky around midnight. On February 6th, Jupiter will be at Opposition, fully illuminated by the Sun and at its closest to the Earth.

The photo in the title bar was taken by me back in September 17th, 2010, only 4 days before its closest approach, which shows that even with a small 80mm scope, quite a bit of detail can be captured when the conditions are right.