ARGH!?!?!?!
Why are they dribbling out this info????
I found 3 MORE faces by merely looking at this picture!(I was just looking for ski tracks among the pine trees when I came across them!)
Posted on 03/25/2002 2:42:10 PM PST by vannrox
Asteroid Vesta: The 10th Planet? Discovery Brightens Odds of Finding Another Pluto Nemesis: The Million Dollar Question HOUSTON, TEXAS -- Our solar system may have had a fifth terrestrial planet, one that was swallowed up by the Sun. But before it was destroyed, the now missing-in-action world made a mess of things. The temporary existence of more than 4 planet-sized bodies in the inner Solar System is consistent with the currently favored model for the formation of the Moon. Work by Chambers and Lissauer also supports the view that our Moon is a leftover of a massive collision between Earth and a Mars-sized body 50 million to 100 million years after the formation of the Solar System. Wendell Mendell, a planetary scientist here at NASA's Johnson Space Center, said the new theory is intriguing. "By thinking that the Solar System was really quite different in a major way with an extra inner planet, we might be able to develop some sort of self-consistent scenario that explains a lot of things. But all this is at the very early stages now," Mendell said. "You're going to have to be very, very specific on what sites you go to collect new samples," Schmitt told SPACE.com. "It may be very difficult to get an answer without using missions to fairly large impact craters that penetrate through the ejecta. Those impacts are sort of a drill hole into the lunar crust," he said.
Space scientists John Chambers and Jack Lissauer of NASA's Ames Research Center hypothesize that along with Mercury, Venus, Earth, and Mars -- the terrestrial, rocky planets -- there was a fifth terrestrial world, likely just outside of Mars's orbit and before the inner asteroid belt.
Moreover, Planet V was a troublemaker.
The computer modeling findings of Chambers and Lissauer were presented during the 33rd Lunar and Planetary Science Conference, held here March 11-15, and sponsored by NASA and the Lunar and Planetary Institute.
It is commonly believed that during the formative years of our solar system, between 3.8 billion and 4 billion years ago, the Moon and Earth took a pounding from space debris. However, there is an on-going debate as to whether or not the bruising impacts tailed off 3.8 billion year ago or if there was a sudden increase - a "spike" -- in the impact rate around 3.9 billion years ago, with quiet periods before and afterwards?
This epoch of time is tagged as the "lunar cataclysm" - also a wakeup call on the cosmological clock when the first evidence of life is believed to have appeared on Earth.
The great cover-up
Having a swarm of objects clobbering the Moon in a narrow point of time would have resurfaced most of our celestial next door neighbor, covering up its early history. Being that the Moon is so small, Earth would have been on the receiving end of any destructive deluge too.
Moon-walking astronauts brought back a cache of lunar material. Later analysis showed that virtually all impact rocks in the "Apollo collection" sported nearly the same age, 3.9 billion years, and none were older. But some scientists claim that these samples were "biased", as they came from a small area of the Moon, and are the result of a localized pummeling, not some lunar big bang.
There is a problem in having a "spike" in the lunar cratering rate.
That scenario is tough to devise. Things should have been settling down, according to solar system creation experts. Having chunks of stuff come zipping along some hundreds of millions of years later out of nowhere and create a lunar late heavy bombardment is a puzzler.
If real, what were these bodies, and where were they before they scuffed up the Moon big time? The answer, according to Chambers and Lissauer, might be tied to the the Planet V hypothesis.
"The extra planet formed on a low-eccentricity orbit that was long-lived, but unstable," Chambers reported. About 3.9 billion years ago, Planet V was perturbed by gravitational interactions with the other inner planets. It was tossed onto a highly eccentric orbit that crossed the inner asteroid belt, a reservoir of material much larger than it is today.
Planet V's close encounters with the inner belt of asteroids stirred up a large fraction of those bodies, scattering them about. The perturbed asteroids evolved into Mars crossing orbits, and temporarily enhanced the population of bodies on Earth-crossing orbits, and also increased the lunar impact rate.
After doing its destabilizing deeds, Planet V was lost too, most likely spinning into the Sun, the NASA team reported.
Striking view
"This idea and others within the last few years show that the Solar System is filled with all sorts of gravitational resonances...that a lot of potential orbits in the Solar System are chaotic and unstable," Mendell told SPACE.com. "My sense is that this is a new idea. It's another thing to throw into the pot that's not totally crazy."
The work suggests there's a match up in timing, Mendell said, with asteroids striking the Moon and causing the effects that are seen in the dating of Apollo lunar rocks.
"We're moving into a really new regime," Mendell added, "where the Solar System is not a static dynamic place from day one to now. It really might have had some nuances and synchronicities associated with it that we have not really tried to exploit before."
It takes a drill hole Setting the early Solar System and lunar history record straight means going back to the Moon.
"The Moon is still the keystone to our understanding of the Solar System," NASA's Mendell said.
That too is the view of Apollo 17 astronaut, Harrison "Jack" Schmitt. Getting back to the Moon to sort out the real story is a must, he said.
Dating service
Places on the Moon where older, large basins have deposited ejecta are ideal research zones, Schmitt said. Digging into such sites could yield impact glass formed by basins perhaps dating older than 3.9 billion years old, he said.
Just taking spot samples -- say from the Moon's South Pole Aitken basin -- could be risky, in terms of uncovering the Moon's rocky history, Schmitt said. Such a huge area would take multiple robotic or human exploration missions, each with significant roving abilities.
Also known as the "Big Backside Basin," Aitken is the largest impact crater on the Moon, and one of the biggest in the Solar System.
For the near term, sets of low-cost, mini-robotic landers carrying specialized gear would be ideal in opening up the Moon to further exploration, Schmitt said.
"Numbers of targeted missions could get a lot of great information on some of these fundamental questions that we still haven't been able to answer," Schmitt said.
Getting back to the Moon with a settlement for resource exploitation is another step forward. From such a site, human explorers can survey various lunar locales - even the Moon's side that we Earthlings never see, Schmitt said. "Then we can do the kind of thing that Apollo did for the near side of the Moon," he said.
No, I am joking about the Holiday Inn, but the limit of my geology knowledge is one class that I took for fun a couple of years ago. I did, however, have a good grasp for the concepts. I hope though that if I accidentally mislead you that there will be a real geologist along to smack me upside the head.
Anyway, if I follow the story correctly, the scientists are not claiming that the dated rocks were those that impacted the moon (as you said, that would be foolish). I believe they are following the theory that the moon "seas" were created by collisions big enough to create a break in the moons crust through which magma flowed and then solidified, creating newer, darker rock on the surface. Since the moon mission that gathered the rocks landed in one of these areas, that would be the type of rocks they would be collecting. Also, since there is apparently no plate tectonic activity on the moon, the only way for new rock to be formed would be through these collisions. Note that according to the article, other scientists make a point that the rock samples were not collected from enough sites to warrant a generalization of there having been one huge cataclysmic event.
Back to the isotopes (and keep in mind that my example isotope, though a common one, may not have been the one the scientists were measuring). Potassium is a very common element in igneous rocks (a common example is potassium feldspar - the creamy pink mineral found in some granite). Argon, on the other hand is a noble gas, rarely forming any compounds. So, I am thinking that most of any argon in the magma at the time of rock formation would escaped as gas. So, the argon found in the rock samples would have been created by the radioactive decay of the K-40 after the rock had solidified and would be trapped in the rock structure.
That is about all I can come up with. Hopefully this helps somewhat. If not, I hope a geologist will wander by and enlighten us.
Keep an eye on Mount Malapert. It's on the moon at latitude 86 south and has sunlight almost all the time. Also, it is in walking range of possible water deposits [ice] in the deep craters that never get sunlight. And, it has a view of the entire earthdisc all the time. Expect the Chinese to set up shop there beginning in 2010.
(I was just looking for ski tracks among the pine trees when I came across them!)
![](http://mem.tcon.net/users/5012/7632/faces.gif")
Why not?
After all, the Bible tells us that the moon was created much later than the earth's rocks, seas, and first life.
Everyplace has this many meteorites, its just you can't see the them.
Usually, those walking that area in Antartica get 1 -2 meteorite rocks per 4 square miles ... most of course, are common generic stony. Only a few (less than twenty) are clearly from Martian "splashes" that actually threw Martian rock high enough to go into orbit and eventually pass into the earth's atmosphere.
Nice sketch of Herschel in Parallax, the Race to Measure the Cosmos.
The book cloys due to too many personal anecdotes by the author, but worth reading.
To be fair about it, some people claim that JPL is to blaim and that NASA is more or less innocent. The claim is that a money struggle is involved, and that JPL funding is mainly if not entirely based on unmanned exploration, which would come to a sudden and drastic halt if the political class finally were to twake up to the reality that a city had been discovered on Mars while people were talking about microbes. There would never be another unmanned Mars probe; they'd all be manned.
My own view is that cities are interesting, and germs are not. I can find germs in my toilet; I don't feel any particular need to fund space explorations to look for germs. Thus, it pretty much pisses me off to keep on reading about searches for microbes while evidence of a city having been found is ignored.
Nope. Vulcan was a hypothetical planet closer to the Sun than Mercury. There were even some claimed observations, but none was verified and the "planet" was never seen again.
The (imaginary) counter-Earth (in Earth's orbit but precisely opposite) has no name, as far as I know. Maybe "counter-Earth", or "Balonia" or something.
And "Nemesis" is a hypothetical star which periodically perturbs the cometary belt and causes an increase in cometary debris hitting Earth. It has never been observed.
--Boris
Ah ha! That was the piece of information I was missing. Being a gas, one can assume a static date based on the idea that the gas would not be in the rock at the time it was formed.
This doesn't help date when a rock (or planet) later was broken up into smaller rocks, but it sure looks like it could be used to date the original formation.
Thanks for the answers and the patience.
just a bttt for a moldy old topic.
Mystery Spot On Jupiter Baffles Astronomers
10/23/03
Posted on 10/23/2003 5:41:53 PM PDT by Davea
http://www.freerepublic.com/focus/f-news/1006938/posts
39 posted on 10/23/2003 6:44:20 PM PDT by Swordmaker
http://www.freerepublic.com/focus/f-news/1006938/posts?page=39#39
Read later, gracias.
At that time there wasn't enough on the Earth to drive extinct!
It's too long ago.
From: http://www.space.com/scienceastronomy/solarsystem/nemesis_010320-1.html
Muller's Nemesis theory -- that our Sun has a companion star responsible for recurring episodes of wholesale death and destruction here on Earth -- seems to reemerge periodically like microbes after a mass extinction.
That's what they told me 3 years ago.
Welcome to a Lazarus Thread...
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