Where In The Universe Challenge #121

It’s time once again for another Where In The Universe Challenge. This awesome image was sent in by UT reader Paul Nadolny. Name where in the Universe this image was taken and give yourself extra points if you can name exactly what all the different objects are in the image, as well as what instrument is responsible. Post your guesses in the comments section, and check back on later at this same post to find the answer. To make this challenge fun for everyone, please don’t include links or extensive explanations with your answer. Good luck!

UPDATE: The answer has now been posted below.

You all are pretty sharp! Paul and I both thought looked like a star hovering over Earth’s limb. But actually, this is Saturn’s limb, with the nearest star system, Alpha Centauri, hanging above the horizon. Both Alpha Centauri A and B—stars very similar to our own—are clearly distinguishable in this image, which was taken by the Cassini spacecraft.

This image is part of a stellar occultation sequence, during which Cassini watches as a star (or stars) as it passes behind Saturn. Light from the stars is attenuated by the uppermost reaches of Saturn’s gaseous envelope, revealing information about the structure and composition of the planet’s atmosphere.

The view was captured from about 66 degrees above the ringplane and faces southward on Saturn. Ring shadows mask the planet’s northern latitudes at bottom.

Thanks again to Paul Nadolny for submitting this image. If you have an image you’d like to submit to try and stump everyone, send an email to Nancy.

See this JPL Photojournal page for more information.