Imagine your children sitting (safely) on your home’s front steps just after sunset. You drive by at 60mph. Can your spouse catch a picture of your kids’ smiles? (Or their gaping open mouths that you’re roaring down the road at double the speed limit?)
With the Cassini probe moving at 40,000 mph just thirty miles above the surface of Enceladus, that’s the challenge: to get some big-time close-ups of the geyser fields around the south pole. The Cassini team slowly rotated the probe to get a “skeet-shooting” style image. Otherwise, the closeness of the camera would blur the images. Let’s also recall that Enceladus, ten times farther from the sun than our speeding friends, basks in one percent of the light we receive at Earth.
Here’s an even tougher task. You’re on in California remote-controlling a toy airplane flying over a Florida beach. Do you dare dive the plane a half-inch above the sand? In the original Cassini mission, the equivalent parameters were no closer than six inches.
With four years of mission success under their belts, the Cassini navigators have aimed the probe to a handful of gutsy 15-30 mile flybys past the icy moon Enceladus. The second of these close passes was completed Monday and the raw images are up. This one is from 320 miles out:
Notice the contrast of these images from the day/night terminator. Here’s a bit of perspective from a little over 10,000 miles out:
How about 1700 miles up?
Carolyn Porco, the brilliant scientist leading the imaging team, blogged about the images late Tuesday. Her post includes links to some remarkable close-ups, plus very accessible descriptions. I advise a visit over there. As quickly as a 60mph car can circumnavigate your cul-de-sac.