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Cassini Shows Close Up of Iapetus
dazza101 writes "The Cassini spacecraft passed within 72,000 kms of the Saturn moon Iapetus yesterday, taking a series of spectacular images of this intriguing moons rugged surface. An excellent prelude to what promises to be one of the major stories of the new year, the plunge of the Huygens probe into Titan's atmosphere on January 24."
That's a "rebound effect". Whatever caused that crater was so big and hit so hard that it penetrated the moon's crust. The more plastic inner material was violently compressed, then shot out through the center of the crater forming the "mountain". It's a rare phenomenon, but I don't have any trouble believing it's natural.
The world is my oyster. That's why it's always in a stew.
Large impact craters are characterized by central peaks. This type of crater ("complex impact crater") is common on the Moon, Mars, Earth, and all other bodies with impact craters. The peak forms by rebound of the crust. This page has some details: http://www.solarviews.com/eng/tercrate.htm
....also many more images if you go straight to the raw feed.
- "Hear that?! The percolations are imminent! Cease your ingress!"
You can see a similar phenomenon in these high speed photos of water droplets.
Here's a crater on the Moon with such a peak. I guess it really gets around.
They're called rebound peaks and they are a common feature of impact craters, and perfectly natural.
~ radiographite: art by john shepard
The Cassini-Huygens mission is a cooperation between NASA, the European Space Agency and ASI, the Italian space agency.
The Huygens plunge is January 14'th, not the 24'th :) 2 Weeks is hard enough to wait for! :)
Be True, Unbeliever
If by "more accurate detail" you read exaggerated artificial relief done with Photoshop, then by all means, check out the photo.
Isn't Huygens plunging into Titan on Jan 14th??
Also, resolution ain't everything. You can bet that this camera, like the mars landers and unlike your generic handheld digi-camera has a CCD an inch or two wide rather than a few millimetres. Good light sensitivity makes up for a lot. Big chunky pixels in the CCD mean fewer dead black spots from radiation and suchlike as well.
And a similar phenomenon is happening here on Earth too. The Himalayas were formed due to the impact of peninsular India when the continents were formed. Well as a 'repulse' to the imapct, peninsular India is now slowly shifting away from the Himalayas. Can this be called a product of Newton's third law on a much greater scale?
The phonetic spelling can be found on Dictioary.com .
Luckily, also being Dutch myself, I have no trouble at all pronouncing this word.. but I do like that supermodel thought! ;)
It plunges on January 14th, not 24th.
Press Release
--- These are not words: wierd, genious, rediculous
SpaceFlight Now:
With a diameter of about 1,400 kilometers (890 miles), Iapetus is Saturn's third largest moon. It was discovered by Jean-Dominique Cassini in 1672. It was Cassini, for whom the Cassini-Huygens mission is named, who correctly deduced that one side of Iapetus was dark, while the other was white.
Not sure how much that vision of the moon has improved since, but going from that to the idea that maybe something went <SPLAT!> on the moon leaving a black circle isn't what I'd call a stroke of genius. (Regardless of wether a splat really caused the dark region, or some other process). Clarke has come up with many great ideas, and promoted great new ideas of others, but this isn't one of them IMHO.
karma capped
Given that comets are currently thought of as having a coating of dark carboniferous goo IIRC, it doesn't seem too unlikely that if one hit a small moon, it could leave a black residue, if the impact wasn't sufficient to vaporise and degrade whatever the goo is.
Some missions (like Galileo) were indeed crashed onto the target planet to prevent them becoming a problem later, or to use the impact as a science data point. Other missions were crashed quite unintentionally.
karma capped
Those streaks are stars, making trails as Cassini moves during the long exposure of 82 seconds.
A "problem" meaning Cassini could bring microbes from Earth and contaminate another world. The purpose of crashing Galileo into Jupiter was to prevent a possible crash into Europa. Since Europa may have a warm water ocean below its icy crust, it has the possibility of harboring life. It is possible that there is now life on Mars, because it was brought there with the Mars rovers.
I've noticed in a lot of the images, there appears to be a ring of mountains around most of Iapetus's equator: Here, here and here....I'm no scientest, but is it possible that this moon once had a ring system like Saturn itself? Over time the ring particles fell out of orbit and formed the mountains along the equator.
The "ring of mountains" is indeed pretty darn odd. Never seen it on any other moon that I know of, at least not one that extends that far around.
But, I doubt falling ring debri would cause such. The material in Saturn's rings does not add up to much if collected in one spot, for example. My speculation is that it is a shock fault caused by a huge meteor impact. However, these usually end up on the opposite side, not around the middle. Whatever it is, I bet a bunch of planetary scientists are happily scratching their heads for answers.
And I thought the "icy" moons would prove boring. I was wrong.
Table-ized A.I.