Orbiter to Probe Moon's Origins

[WitchBoy]

The European Space Agency took delivery Tuesday of a little device it hopes will unlock one of our biggest mysteries: is the moon a cleaved-off chunk of planet Earth, or was it a vagabond planetoid that got caught in Earth's gravitational embrace?

Scientists hope the D-CIXS — pronounced "dee-kicks" and standing for Demonstration of a Compact Imaging X-ray Spectrometer — will come up with some answers by creating the first complete high-resolution map of the moon after it is launched early next year.

The 3-kilo (6.6-pound) toaster-sized unit was designed by an international team in Britain and its $2.5-million cost was covered by the ESA, the British National Space Center and Britain's Particle Physics and Astronomy Research Council.

The D-CIXS will monitor and record various light-wave readings as it traces an elliptical orbit around the moon that will bring it to within a half a mile of the lunar surface. Its data on magnesium and iron ratios, for example, should provide clues to the moon's origin, while other information will determine whether there are traces of ice at the moon's poles.
There are two main theories about how the moon came to be. One says a huge impact, maybe caused by a meteorite, sheared off a bit of the Earth and sent it spinning off into orbit. The other hypothesizes that a passing body was "grabbed" by Earth's pull.

D-CIXS will conduct its six-month mission from within a satellite to be launched aboard an Ariane-5 rocket from French Guyana in South America next February, called SMART-1, or Small Mission for Advanced Research and Technology.

The project represents Europe's first foray to our natural satellite, which has up to now been the research domain of Russia and especially the United States.

If the technology used in the mission proves successful, it will be used in more ambitious space exploration, including in the BepiColombo probe to Mercury that Europe and Japan plan to launch in 2009.

[Chaos_Childe]

Hmmm the moon is potentialy a chunk of the Earth

Nah I don't believe that in the slightest. Something 1/4 the size of our planet just happens to be lost and we don't see the slightest sign of such a loss???

Also the moon just happens to be round?. A chunk of anything which is a complete shape is improbable to be round. Without the effect of something like a melon baller.

As reported in news.nationalgeographic.com/news/2001/08/0820_moonimpact.html the problems of the moon being from the earth are:

" the mass of the Earth was right, as was the composition of the moon. But the Earth's rotation rate after the collision was unrealistically fast. An improbable second impact would have been required to slow the Earth's spin.

A second scenario suggested that the impact occurred when Earth was only half formed. That idea better explained the Earth's modern rate of rotation and the moon's orbit, but it required Earth to continue accumulating matter after the impact. That material would have been rich in iron, which composes 30 percent of Earth's mass. But the moon, which contains almost no iron, would have simultaneously absorbed similarly iron-rich rock. The model offers no way to explain the moon's confounding dearth of iron. "

I support the theory that the moon was a rogue planetoid which was caught in the Earth's gravitational field.

[jimbo]

Hmmm the moon is potentialy a chunk of the Earth

Nah I don't believe that in the slightest. Something 1/4 the size of our planet just happens to be lost and we don't see the slightest sign of such a loss???

It probably was a comet that impacted in the present-day Pacific Ocean. The impact threw tons of debris into our atmosphere, eventually combining with the chunck of comet orbiting the Earth. Since the debris was mostly fine dust, it settled on the moon in a circular shape.

Also the moon just happens to be round?. A chunk of anything which is a complete shape is improbable to be round. Without the effect of something like a melon baller.

See above...

" the mass of the Earth was right, as was the composition of the moon. But the Earth's rotation rate after the collision was unrealistically fast. An improbable second impact would have been required to slow the Earth's spin.

The dinosaurs were wiped out by a large asteroid moving at about 25,000 mph.

A second scenario suggested that the impact occurred when Earth was only half formed. That idea better explained the Earth's modern rate of rotation and the moon's orbit, but it required Earth to continue accumulating matter after the impact. That material would have been rich in iron, which composes 30 percent of Earth's mass. But the moon, which contains almost no iron, would have simultaneously absorbed similarly iron-rich rock. The model offers no way to explain the moon's confounding dearth of iron. "

I disagree. As on Earth, oxygen is the most abundant element on the Moon's surface but in the form of oxides. There are lots of silicates everywhere. Magnesium, iron and titanium are enriched in the surface of the maria, (as well as other areas, but I didn't want to make this boring for anyone ;D) as is an abundant quantity of pyroxene. The highland rocks consist mainly of feldspar, enriched with calcium and aluminium. Three minerals unknown on Earth have been discovered on the Moon. There are also traces of sulphur, phosphorus, carbon, hydrogen, nitrogen, helium and neon in the soil.

I support the theory that the moon was a rogue planetoid which was caught in the Earth's gravitational field.

Why is the moon not following a large eliptical orbit, then?

[Nemesis]

Jimbo is right.. Moon > chunk of earth. BTW; the reason it's circular is just bcuz earth consisted of hot rock. such an impact would rip out a chunk which could be shaped easily to a ballshaped object (moon ;D).
The impact DID leave a scar on Earth.. ill try to find the image for ye

[Nemesis]

The crater i meant is the Chicxulub crater, which is believed to be the largest meteorcrater on the earth. Its found off the Yucatan Peninsula in the Gulf of Mexico. The Chicxulub crater is 150-300 km in diameter. Tho it's not the crater caused by the meteor which caused to break off a chunk of earth, it IS supposed to be the meteor which caused the extinction of dinosaurs.

artistic impression (pic by NASA):


3D map:

[Chaos_Childe]

I am not denying that a metor's have hit the earth in the past. I also support the theory that one caused the destruction of the dinosaurs.

I just find it hard to believe that one could have removed a 1/4 of a planet without it destroying the planet. I could be wrong but that is the way that I see it.

I also accept that there are many minerals that exist on the moon that exist on Earth. But those elements can be found on the other planets that exist within our solar system. Those planets are not part of the Earth. Yet the question of why there is such a lack of Iron on the moon still remains unsolved.

Three minerals unknown on Earth have been discovered on the Moon.

Which supports my theory that it has more than just an Earthly origin.

It also seems likely that debris from the various meteor strikes on this planet (like from the Chicxulub crater) could have settled on the moon. After all it is the closest body to the earth and has a gravitaional pull of its own. The moon's gravitational pull even effects our planet today.

This doesn't mean that it's entire origin was a piece of the Earth.

chunck of comet orbiting the Earth

A point that you seem to slightly agree with.

(b.t.w. Nem thats a great picture of the Earth)

[Nemesis]

This better? ;D

[Frink]

Chaos_Childe said:

Also the moon just happens to be round?. A chunk of anything which is a complete shape is improbable to be round. Without the effect of something like a melon baller.

Something as large as the moon must be round.

I support the theory that the moon was a rogue planetoid which was caught in the Earth's gravitational field.

The celestial mechanics behind such a scenario are so improbable as to be mind-boggling.

[Nemesis]

The moon only MUST be round if the material would be fine dust or viscose while being 'shaped', and it's gravitation is coherent to its spinning movement. If the centrifugal force caused by its spinning movement is too heavy itll be more disc-shaped..
The 'caught in'-scenario is only improbable bcuz of the Earth-Moon size relation. Our Moon pretty large for Earth, thus leading to the conclusion that Earth's gravitational pull is too weak to grab a moon-sized moving object into its orbit. When ye compare Jupiter or Saturn to its moons, you'll notice they differ very much in size. When a planet got a moon more than 1/3 of its size, it's more common to consider those double-planets (or brothers) than planet-moon.
The scenario of a moon as a captured object isnt impossible, actually, its even more possible than other scenario's. Take Mars for example. Deimos and Phobos are both planetoids..

[Frink]

Nemesis said:

The moon only MUST be round if the material would be fine dust or viscose while being 'shaped', and it's gravitation is coherent to its spinning movement. If the centrifugal force caused by its spinning movement is too heavy itll be more disc-shaped..

Anything with that much mass must pull itself into a round shape. Even pulsars, spinning several times per second, are round.

The 'caught in'-scenario is only improbable bcuz of the Earth-Moon size relation. Our Moon pretty large for Earth, thus leading to the conclusion that Earth's gravitational pull is too weak to grab a moon-sized moving object into its orbit.

The moon would have had to have come in very near the correct angle at the correct velocity to avoid smashing into the Earth (or entering the Roche limit) or escaping Earth's gravitational pull altogether. I wouldn't expect an object as large as the moon to have so little momentum.

It's not impossible, but it's very unlikely.

[Nemesis]

Frink said:

Anything with that much mass must pull itself into a round shape. Even pulsars, spinning several times per second, are round.

The moon would have had to have come in very near the correct angle at the correct velocity to avoid smashing into the Earth (or entering the Roche limit) or escaping Earth's gravitational pull altogether. I wouldn't expect an object as large as the moon to have so little momentum.

It's not impossible, but it's very unlikely.

Isnt that what I said? Very unlinke. But possible.
Anyway, if everything what spins must be round, then tell me how the heck it is possible that most stelarsystems are unshaped or discshaped...

[CatBreath]

they are not A large chunk of matter
they ARE large chunks of matter

[Frink]

Nemesis, spinning has nothing to do with such masses necessarily being round. They must be round because their own gravitation pulls them into spherical shapes; corners aren't allowed. As you said, fast spin rates tend to make spinning bodies bulge in the equatorial regions, but they are still spherical.

[Nemesis]

They are spheres only because a sphere is the most simple shape possible in a 3D world. Otherwise the smallest particles would be cubes ;D
No offence, but you started about spinning:

Anything with that much mass must pull itself into a round shape. Even pulsars, spinning several times per second, are round.

Disc-shaped stelarsystems are round/disc shaped due to high-speed spinning. Unregular systems are not because they dont spin. So spinning DOES cause the shape to be different.