Skip to comments.Catastrophism
Posted on 04/02/2006 2:13:59 PM PDT by SunkenCiv
Did a planetary wobble kill the dinosaurs?Bruce Runnegar from the University of California at Los Angeles' Center for Astrobiology... and his colleagues used computer models to map out the Solar System for the past 250 million years. In particular, they looked at the perihelion of each planet - the point in its orbit where it is closest to the Sun. The perihelion of Earth rotates around the Sun with a period of hundreds of thousands of years. Because of subtle tugs and pulls between the planets, this period changes slightly with time... Their model suggests one of these blips significantly changed Mercury's orbit 65 million years ago. This wobble would have pulled at the asteroid belt, increasing the chances that asteroids in the Hungarias region would be knocked out of place. Now the researchers are running a fresh set of models to see how much the orbits of these asteroids changed. It wouldn't have been enough to send a shower of asteroids into the Earth, but Runnegar says the wobble could have sent a single asteroid onto collision course with our planet... Now he is planning to run his models forward in time, to see when the next potentially catastrophic planetary wobble will be.
by Nicola Jones
June 27 2001
Did the new moon lose its iron heart?The current theory says that the material that now forms our moon was ejected when Earth was struck by another planet-sized body. But Peter Noerdlinger at Saint Mary's University in Halifax, Canada, says this theory has problems. "The collision has to be implausibly gentle. You practically need someone to hold a Mars-sized object just above Earth and drop it, to avoid messing up Earth's orbit."
January 23, 2007
The simpler idea that Earth and the moon were both created from the same gas cloud had been rejected because it could not explain why Earth formed an iron core and the moon did not. Now, Noerdlinger has an answer for that.
He suggests that the proto-moon did have an iron core, but that the satellite was ripped apart in a close encounter with Earth. His calculations show that iron from the core would be pulled towards Earth, while the remains of its rocky outer shell reassembled into our iron-free moon.
This fits with evidence that the Earth acquired a veneer of iron after it formed, Noerdlinger says. He presented the work at the American Astronomical Society meeting in Seattle, Washington, last week.
From issue 2587 of New Scientist magazine, 23 January 2007, page 16
cosmic ray bombardment:
Astronomy Picture of the Day 9-12-02
NASA | 9-12-02 | Robert Nemiroff and Jerry Bonnell
Posted on 09/12/2002 1:37:17 AM EDT by petuniasevan
Bright star: Four centuries later, fresh insight into historic find
Yahoo (AFP) | Wed Oct 27, 2:00 PM ET
Posted on 10/30/2004 3:09:45 AM EDT by Thinkin’ Gal
Discovery 2008The hypothesis suggests that collisions between large objects like Pluto and Eris and others out in the Kuiper belt played a much larger role in sculpting these objects than anyone previously thought, and, in particular, the collisions removed much of the ice that these cold objects would have had in their interiors... For my hypothesis there are two tests. The first is to show that a giant collision indeed removes ice. The second is to show that an object that has a lot of ice didn't have a giant collision... In my hypothesis, this giant collision that happened on Quaoar long ago should have removed most of the ice inside of Quaoar, meaning that the interior should be much more rock than ice... If Quaoar is heavy and rock-like, [its] moon will be pulled along quickly, while if Quaoar has more ice and is lighter, the moon will take longer to go around... Another giant Kuiper belt objet and dwarf planet, Orcus..., also has a moon... For my hypothesis to be correct, this moon must be captured, because otherwise my hypothesis would predict that Orcus should be rocky, not icy... Like the first test, the results of this second test will be apparent almost instantly. In only a few hours I should be able to figure out what the moon of Orcus has on its surface. If the moon of Orcus looks like it was made in a collision I will again have to toss the hypothesis out. But if the moon appears captured, the hypothesis will have survived two important tests, and it will suddenly have to be considered seriously.
Mike Brown's Planets
Monday, December 31, 2007
I think he's trying to say this is hugh and series, isn't he?
Heh... the whole thing reminds me of “theory, by Anne Elk”.
Oh no, not more homework! Give me a hint...
Monty Python. :’)
Anomalous Trajectories of deep space probes
Thunderbolts.info | 03/04/2008
Posted on 03/16/2008 5:22:27 AM EDT by Swordmaker
The “Galactic Mask” Unveiled
thunderbolts.info | 03/12/2008
Posted on 03/16/2008 6:11:29 AM EDT by Swordmaker
Mira: The Tale of a Giant Star... with a tail
thunderbolts.info | 03/03/2008 | Stephan Smith
Posted on 03/16/2008 5:11:17 AM EDT by Swordmaker
Saturn’s Plasma Ring
Thunderbolts.info | 03/06/2008 | Stephan Smith
Posted on 03/16/2008 5:49:59 AM EDT by Swordmaker
When Winds Collide
thunderbolts.info | 03/07/2008 | Stephan Smith
Posted on 03/16/2008 5:59:55 AM EDT by Swordmaker
Highly recommended if you can tear yourself away from Flagstaff and Canyon de Chelly.
If ever I ride through there again, I plan to check it out. 3/4 a mile across? More than just a big hole in the ground. :’)
Added blam just the one time. A couple of links, no biggie:
Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling
Chicxulub and the Cretaceous Tertiary Boundary
Thanks. Bookmarked to read during the next blizzard.
Vulcan and Comets Related Sites
Comet/Earth Impact Chronology
28 February 2008
The goose that survived crashing into a meteorite only to be savaged by a fox!
February 5th, 2008 - 5:14 pm ICT by admin
London, Feb 5 (ANI): A goose survived being hit by a 9lb meteorite and crashing into a car only to fall prey to a hungry fox.
And, witness to all this was Brit postman Adrian Mannion who was enjoying his morning cup of tea with wife Fiona when the bizarre set of events unfolded.
According to Mannion, the Canada Goose was left dazed when after banging into a meteorite, it fell headlong into his cars roof, causing 2,500 pounds worth of damage.
However, there was no reprieve for the bird, for a hungry fox then grabbed it dragged it away before the Mannions could rescue it.
We heard two almighty thuds and rushed out to see this large, odd-looking rock next to our Mini and a very poorly-looking mangled goose on the car roof, The Sun quoted Mr Mannion, as saying.
A flock of Canada Geese were overhead so the falling stone must have hit the poor creature.
Mrs Mannion added: It has to be the unluckiest bird ever. It survived being knocked out by a meteorite only to be savaged by a fox.
The meteorite is now being studied by researchers at the University of Derby. It is one of only 1,000 asteroid fragments that hit earth each year. (ANI)
from the History Channel:
A FReeper posted this link (thought gleeaikin did, but didn’t see it):
Many astronomical links ping
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