Two nights ago, Jupiter reached a point in its orbit known as ‘opposition‘. This essentially means that it lies in the opposite direction to the Sun – rising as the Sun sets, and reaching its highest point in the sky at around midnight. This configuration also means that the Earth is about as close to Jupiter as it’s going to get this year – making it the ideal time to break out the binoculars or telescope for a look, or even perhaps a camera for some planetary imaging.
In the above image – taken one day after opposition (blame the clouds!), and a couple of days after the rare triple transit – the largest planet in the solar system is escorted by a moon with the highest level of volcanism in the solar system; Io. Io is a fascinating place, constantly spewing sulfur compounds into space which fall into orbit around Jupiter. These interact with the planet’s enormous magnetic field, forming structures known as the Io plasma torus and flux tube. It is the innermost of the four Galilean moons, all of which are easily visible through binoculars or a telescope, and which even show up when using a DSLR and moderate focal length lens. When observing or photographing Jupiter, a planetarium program like Stellarium (which is free) will help you to work out which moon is which.
For those interested, the image was taken using a monochrome ZWO ASI120MM Astronomy camera, and Celestron CPC 800 Telescope, plus the 2x Barlow lens found in the Celestron Accessory Kit. I recorded about 1500 frames, then stacked the best 150 using Registax 6. Some final processing (brightness, contrast, sharpening, etc.) was then done in Adobe Photoshop.
The cloud bands and Galilean moons of Jupiter are always a treat to observe (or photograph), though obviously opposition means the view is just that much better. The largest planet in the solar system is hard to miss, being the brightest “star like” object in the eastern sky during the evening, and shining high overhead around midnight.
(NB: For those of us in the southern hemisphere, Jupiter will cross the mid-high northern sky, while our upside-down friends in the northern hemisphere should look to their southern sky).
Disclosure: Please note that some of the links on this site are “affiliate links”. If you click on these links and make a purchase, we receive a small commission, however the price to you is not affected. This helps us keep the price of our outreach activities as low as possible. See the Affiliate Disclosure section of the website terms and conditions for more details.