Well this animation has been a long time coming. Back on the 5th July 2009, Ganymede and Callisto had a close approach – no occultation unfortunately, but it was still great to see them so close together.

Ganymede, at 5,200km diameter (1.7 arcseconds) and Callisto at 4,800 km diameter (1.6 arcseconds) are both over 635 million km away. The seeing was only just above average, but both moons show consistent albedo features throughout many frames of the animation.

Click the image below to view the 15 frame animation which covers just over 2 hours of elapsed time.

Ganymede and Callisto Close Approach Animation. Click to Play.

Please read on to find out more about the capture and processing.

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Last night started like every other – typically below average seeing, but instead of going back to bed, I waited it out – hoping it would get better. And it did!

The seeing peaked at 7 – 7.5/10, on a night when there was a fair bit going on. The GRS transited earlier, followed by the Wesley Impact Scar, along with Ganymede’s shadow and then Ganymede itself.

The image below is the first one I’ve finished processing, and is one of the last of the session. It shows the Wesley Impact Scar at top left, and Ganymede’s shadow and Ganymede on the right.

Jupiter, Ganymede and Shadow

The “Bird Strike” has really elongated out over the past few days, as it gets torn by the jetstream.

Continue reading for more..

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UPDATE: See below for a new colour image of Io and Ganymede.

This morning I was able to capture my first Galilean Moon occultation, when Ganymede passed in front of Io, covering about 40% of the volanic moon.

The seeing was reasonably stable, maybe 6.5/10 and the morning started off beautiful and clear. Some cloud bands came through right at the wrong time, ruining some of the sequences right in the middle of the occultation. Of course it cleared completely after the event was all over.

Despite the annoying clouds almost ruining my chances of capturing anything of the occultation, I was able to image enough of the event to put together this 32-frame animation, covering 33 minutes of elapsed time. Detail and albedo features can be seen on both moons. Click the image to play the animation.

Ganymede Occulting Io - click to play

Continue reading to find about my capture and processing settings for this event, and why it’s even so special at all.

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On the morning of the 12th May, I had some very good seeing – the best I’ve had all year, and I was able to record some images of Jupiter and Ganymede in very good conditions, allowing surface details (albedo features) to be seen on Ganymede – one of the Galilean Moons of Jupiter, 750 million kilometres away!

I’ve created an animation of the best frames from the morning session – click the image below to view the animated gif. Keep reading on to see the best individual images and more technical details.

Jupiter and Ganymede Animation: Click to Play

The animation spans almost 1.5 hours, starting with the last of Ganymede’s shadow as it finished transiting the disc of Jupiter, and ends with Ganymede about 20 minutes away from starting its transit.

Continue reading for more information and to see the best individual frames from the morning session.

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Seeing was great this morning, 12th May local time, the best I’ve had all year. Ganymede was approaching Jupiter, soon to begin transit. 

Here’s one of the 11 images I captured from this morning – the first one to be fully processed and one of the best from the session. The others are still at various stages of processing – more to come in the next day or so – plus an animation of course!

There is an NEB outbreak setting on the bottom left, as well as a large rift on the NEB rotating into view on the right. Ganymede has a number of albedo markings too, including a bright spot on the southern tip.

Jupiter and Ganymede in Very Good Seeing!

After the shocking run of seeing I’ve had this year so far, finally the good seeing is starting to come. I can’t tell you what a joy it was to process this image after the rubbish I’ve been processing for months!

More details to come when the final images and animation are ready.

Thanks for looking.

In the From the Vault series, I feature an older image which hasn’t been seen here before and I talk about the capture and processing and hopefully highlight why this image is special to me.

The feature image in From the Vault this week is a portrait of Jupiter and the Galilean Moons, the Jovian system in high resolution. Captured on May 11th 2007, this was one of my most ambitious projects of that year, and took hours to capture and many many more hours in processing. It shows Jupiter with her 4 Galilean moons, Europa, Callisto, Ganymede and Io all at the same scale, in their correct positions at the time of capture.

It’s a good time for this image to be featured again, in the International Year of Astronomy – 400 years since Galileo first used a telescope to observe Jupiter’s Moons.

Jupiter and the Galilean Moons (click for full size)

I took 6 images to create an animation, showing the rotation of Jupiter and the dance of Jupiter’s Moons as they orbit the gas giant. Please continue reading to read more about this image, and to see the animation.

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In the From the Vault series, I feature an older image which hasn’t been seen here before and I talk about the capture and processing and hopefully highlight why this image is special to me.

The feature image in From the Vault this week shows a Dynamic Jupiter in Motion with an image montage and a 21-frame animation bringing Jupiter alive and is something you must see! You can watch Ganymede and Europa transit across the face of Jupiter, the GRS rotate into view, and the volcanic moon Io pop out from behind Jupiter in the last few frames. Albedo features on Ganymede are visible in practically every frame, including while transiting Jupiter, and icey Europa actually reveals its crescent phase while contrasted against the backdrop of the gas giant.

This montage of images was captured on the morning of the 23rd March, 2007 over a period of more than 2 hours in conditions that peaked in the excellent range. Click the image to see the full-size version.

Dynamic Jupiter (click image for full-size)

Continue reading to see the animation and learn more about the capture and processing of this image.

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New images of Jupiter are always news-worthy, and this is no exception. I received an interesting link on the ALPO_Jupiter yahoo group the other day – it’s a pretty fascinating animation showing Ganymede being occulted by Jupiter.

Here’s a still from the movie:

(NASA, ESA and Erich Karkoschka - University of Arizona)

Read on to see the animation and to see one of my own images taken just a couple of hours later after the Hubble image above!
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I’d been looking forward to this busy night on Jupiter for over a week and was lucky enough to wake to clear skies and above average seeing. Unfortunately though, I’d only captured 3 runs before blanket cloud put an early end to the session. Very disappointing, as I had a feeling the seeing would’ve improved as Jupiter increased in altitude. I woke again for work at 5am to clear skies, but I’ll tell myself that it only cleared a few minutes earlier. It’s less depressing that way.

In this image, captured on the morning of the 26th May, the GRS + LRS and new red spot have just rotated into view, Europa is casting a shadow near Ganymede which is in transit, and Io is heading back towards Jupiter soon to be eclipsed by Jupiter’s shadow. In the NNTZ, the little red spot has a white oval approaching it that may merge (noted by John Rogers in one of Tomio’s recent images).

Jupiter + GRS, Europa + shadow, Ganymede + Io

Regarding my imaging, I’ve also solved the problem I was having with lack of light – I washed both mirrors of my 12″ newt on the weekend which had a dramatic effect and allowed me to capture at 30fps with a full histogram (in green especially). Amazing how much of a haze had built up on the mirrors after months of dewey nights. I also took the opportunity to cut a trap-door in the tube down near the mirror, to help me de-fog the mirror when I start losing transparency in future.

Here also is a a simulation showing Ganymede from both the NASA Solar System Simulator and Starry Night Pro. It shows very well correlated albedo features with my image of Ganymede in transit.

A short 3-frame animation of the session can be downloaded here:

Jupiter animation

Thanks for looking. Comments welcome.