Information gleaned form Cassini, Galileo and New Horizons missions seems to indicate that ripples seen in the rings of Saturn and Jupiter were caused by comets. Shoemaker-Levy 9 (famous for a multiplicity of impacts on Jupiter in 1994) left one set of ripples. Saturn’s cometary clues date to a cloud of icy debris passing through the inner rings in 1983.
“What’s cool is we’re finding evidence that a planet’s rings can be affected by specific, traceable events that happened in the last 30 years, rather than a hundred million years ago,” said Matthew Hedman, a Cassini imaging team associate, lead author of one of the papers, and a research associate at Cornell University, Ithaca, N.Y. “The solar system is a much more dynamic place than we gave it credit for.”
Well, I suspect that was already suspected … how likely is it that the rings around these large planets were formed billions or even millions of years ago and have remained untouched? Clearly, they must reform and even re-accrete material over time as varoius snowballs and rocks mess them up now and then.
But, knowing the details is interesting and important, and it is rather impressive that we can see decades old evidence. This may mean that multiple ancient (but how ancient we do not know) events can be reconstructed by studying the rings:
“We now know that collisions into the rings are very common – a few times per decade for Jupiter and a few times per century for Saturn,” Showalter said. “Now scientists know that the rings record these impacts like grooves in a vinyl record, and we can play back their history later.”
The ripples also give scientists clues to the size of the clouds of cometary debris that hit the rings. In each of these cases, the nuclei of the comets – before they likely broke apart – were a few kilometers wide.
“Finding these fingerprints still in the rings is amazing and helps us better understand impact processes in our solar system,” said Linda Spilker, Cassini project scientist, based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Cassini’s long sojourn around Saturn has helped us tease out subtle clues that tell us about the history of our origins.”
Read the whole press release, find out about the published papers, and see the pretty pictures here.
When first discovered in 2010, the Stuxnet computer worm posed a baffling puzzle. Beyond its unusually high level of sophistication loomed a more troubling mystery: its purpose. Ralph Langner and team helped crack the code that revealed this digital warhead’s final target — and its covert origins. In a fascinating look inside cyber-forensics, he explains how.
Continue reading Cracking Stuxnet, a 21st-century cyber weapon
“The human voice: mysterious, spontaneous, primal.” With these words, soprano Claron McFadden invites us to explore the mysteries of breathing and singing, as she performs the challenging “Aria,” by John Cage.
Continue reading Claron McFadden: Singing the primal mystery
The Anti-Evolution Bills in Tennessee have advanced.
Tennessee’s House Bill 368 was passed by the House Education Committee on March 29, 2011, and referred to the House Calendar and Rules Committee, while its counterpart, Senate Bill 893, is scheduled to be discussed by the Senate Education Committee on March 30, 2011. These bills, if enacted, would require state and local educational authorities to “assist teachers to find effective ways to present the science curriculum as it addresses scientific controversies” and permit teachers to “help students understand, analyze, critique, and review in an objective manner the scientific strengths and scientific weaknesses of existing scientific theories covered in the course being taught.” The only examples provided of “controversial” theories are “biological evolution, the chemical origins of life, global warming, and human cloning.”
Read all about it here.
Antievolution bill in New Mexico dies
New Mexico’s House Bill 302 died in committee on March 19, 2011, when the legislative session ended. The bill had been tabled by the Education Commitee of the House of Representatives on a 5-4 vote on February 18, 2011. A version of the currently popular “academic freedom” antievolution strategy, HB 302, if enacted, would have required teachers to be allowed to inform students “about relevant scientific information regarding either the scientific strengths or scientific weaknesses” pertaining to “controversial” scientific topics…
Read all about it here.
For that special organization or person that makes you throw up a little in your mouth when you hear about their latest aggravating attack on our children’s education, by way of making fun of something that is not really all that funny, DontDissDarwn Central annually awards the highly alliterated angs-ridden accolade: The Upchucky. And this year’s award is bestowed, nay, foisted on Answers in Genesis, for their latest dumb-ass venture, the Noah’s Ark Park.
“rooted in outright opposition to science…[this] hostility to science, knowledge and education does little to attract the kind of employers that will provide good-paying jobs with a future.”
Click here to read about all of the nominees and find out what they wore to the ceremony.
“Puppets always have to try to be alive,” says Adrian Kohler of the Handspring Puppet Company, a gloriously ambitious troupe of human and wooden actors. Beginning with the tale of a hyena’s subtle paw, puppeteers Kohler and Basil Jones build to the story of their latest astonishment: the wonderfully life-like Joey, the War Horse, who trots (and gallops) convincingly onto the TED stage.
Continue reading The genius puppetry behind War Horse
As I tune in to NHK live TV, and see the piece on using Twitter to aid in disaster relief being shown for the 20th time over the last 48 hours, I wonder about what appears to be a sudden and dramatic drop in the level of coverage of the Fukushima nuclear power plant disaster. Over the last several days, the IAEA has stopped bothering to note that cooling systems are still not working and have shifted their attention to monitoring the rising radiation levels outside the plant on both land and sea. Meanwhile, TEPCO engineers are speaking of covering the reactor plant with a big blanket of some kind while reasonably credible sources (i.e., those involved in building the plant) seem increasingly convinced that one reactor’s core has breached its containment vessel.
We have mainly been simply reporting what the Internet has been saying, what the Japanese news has been saying, and what the International Atomic Energy Agency has been saying. This is interesting because Ana’s feed is live and catches with its currency and all the quirks and foibles along with the news, the Internet is a diversity of reaction delayed by hours, and the IAEA response is at least a day behind, measured, and we presume most accurate.
And, of course, we have been told to quiet down in a number of ways by a number of people. First we were told to quiet down because there really could not be a disaster here. Radiation could not really escape at serious levels. The buildings that exploded were not really needed. They are supposed to explode, so it is no big deal. The containment vessel is so solid that nothing can get out of it. Anyway, the Tsunami is the real disaster. Automobile deaths are the real problem. Food poisoning is where we should be focusing our attention. And, most recently, asking questions about what is happening during a very current and very real nuclear power plant disaster is offensive to the hard working people who are in danger at the plant.
We are not amused with the screeching monkeys.
Here’s what we’ve got:
Continue reading Japan quake, tsunami, nuke news 13: When in doubt, throw a towel on it.
It is said that it is physically impossible for the nuclear material in any of the Fukushima reactors to melt through the containment vessels. Despite a rumor of a crack in one of the vessels, nuclear power experts have maintained that it is impossible that there could be such a crack. Nonetheless, a US based GE-connected nuclear engineered who has ties to the Fukushima facility has boldly asserted that he thinks that the core in reactor 2 has “melted through the bottom of the pressure vessel … and at least some of it is down on the floor of the drywell.”
Richard Lahey was head of safety research for this kind of reactor for GE at the time that they installed the units at Fukushima. He has told his analysis to The Guardian. You can read it here.
NHK news service has not mentioned this, nor has the International Atomic Energy Agency. This is utterly unconfirmed and probably not true. It is, after all, impossible.
But if it is true, this places the situation at Fukushima on the high side of the TMI tickmark on the scale of badosity. The core at Three Mile island got all messed up but it did not breach its containment.