November 16th, 2013
Cue Carl Sagan, reading from Pale Blue Dot.
Cue Carl Sagan, reading from Pale Blue Dot.
Back in 2004 the Cassini probe discovered a tiny, previously unnoticed moon that was designated Saturn XXXII before being given the name Methone.
Such are the orbital mechanics of the Saturn system and Cassini's orbital trajectory that it's taken nearly eight years for the probe to get close enough to take a high resolution image of Methone. It's been worth the wait.
What an odd looking moon.
Emily Lakdawalla has produced a remarkably detailed (and really pretty) picture of Janus and Saturn:
In the last few days as it's rounded periapsis in its current orbit of Saturn, Cassini has taken a lot of great photos of Saturn's moons. One series of photos was taken from pretty close to Janus, a moon about a third the diameter of Enceladus that orbits between the F and G rings. And among those, several were taken with the moon sitting in front of Saturn. I couldn't resist downloading and playing with these; here's the result of a bit of work with an infrared-green-ultraviolet color composite.
Chris Abbas has stitched together a vast number of still images from NASA's Cassini probe to produce Cassini Mission, a stylish, impressionistic piece that looks nothing at all like your typical NASA video. (And I mean that in a good way.)
What would it look like to approach Saturn in a spaceship? One doesn't have to just imagine — the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and thousands more since entering orbit. Recently, some of these images have been digitally tweaked, cropped, and compiled into the above inspiring video which is part of a larger developing IMAX movie project named Outside In.
Spectacular is the only word for it.
Emily Lakdawalla on a possible explanation for Saturn's hexagon:
The hexagon was first observed in Voyager images of Saturn, and immediately excited curiosity among scientists. In the years following Voyager, an oft-cited explanation for the origin of the hexagon was that it was a standing wave in Saturn's atmosphere. In order for it to be persistent, something needs to be driving it; that something was postulated to be a large, solitary storm observed in Voyager images at a latitude just south of the hexagonal feature. There were problems with this explanation, though, the chief one being that Cassini sees no such solitary storm, yet the hexagon is still there.
In an article published in the April issue of Icarus, Ana Aguiar and her coauthors advance an alternative explanation, and test it in the laboratory. [...]
Fascinating stuff, especially the videos of some of their laboratory tests.
I've seen still images of Daphnis causing a perturbation in Saturn's A Ring before, but this Cassini video of Daphnis ploughing through the rings was new to me. Seriously cool.
8. Greg in Austin Says:
February 15th, 2010 at 11:37 am
I can imagine one of the Cassini engineers here on Earth programming in the flight pattern:
Engineer: "Keep your distance, but don't look like you're keeping your distance."
Engineer: "I don't know. Fly casual!"
As Saturn's seasons turn, the rings cast some really interesting shadows.
Emily Lakdawalla demonstrates why it's well worth looking closely at seemingly mundane astronomical photographs: in this case, a image of part of Saturn's ring system…
Why's this image cool? We're looking at the rings, and the long skinny finger coming in to the image from the bottom is clearly the shadow from one of the moons. But wait, this image rewards closer inspection. Let's zoom in…
Follow the link to find out what's so interesting.1
JPL's John Spencer on the proposal to extend the Cassini probe's mission until 2017:
The year 2017 is special because May 2017 marks northern midsummer in the Saturn system, and the more elegant alternative name for the [further extension to the mission] is the Solstice Mission. A Saturn year is 29.4 Earth years, and the considerable 27 degree tilt of Saturn's pole (which, incidentally and bizzarely, can probably be blamed on the planet Neptune), means that the slow progression of the seasons has major effects, especially on Saturn itself and on its giant moon Titan.
We arrived at Saturn in July 2004, in the depths of northern winter, equivalent to January 15th on a terrestrial calendar. The southern poles of Saturn and its entourage of large satellites were brightly illuminated by sunlight, and the northern poles were in darkness. The shadow of Saturn's rings was draped dramatically across most of the planet's northern hemisphere, robbing even mid-latitudes of sunlight. The entire northern hemisphere of Saturn had the winter blues, literally — the yellowish haze that normally gives Saturn its golden color was missing, leaving a clear blue sky that made a striking contrast with the yellow hues of the southern hemisphere.
It's one thing to know, intellectually, that the outer planets have much longer orbital cycles than Earth's: I suppose I must have absorbed that fact when I read about the Pioneer missions back in the 1970s. Seeing the practical implications spelled out – the notion that our probes would have to hang around Saturn for 30 years just to get the chance to observe a year's weather patterns – makes it all more real, somehow.