Astronomy 101

Excelent thread.

Do you know any "common science" materials about how our moon
got there in the first place?

S&F

[]´s
RP

reply to post by RobertPaulsim


Yes,actually there are three theroies.........

1.Our moon is a trapped planetoid.
2.Our moon was created when about 3.5 billion years ago a massive asteroid or comet slammed into primordial Earth and took a chunk out of what is now the Pacific Ocean(pretty large uh)and the resulting debris were trapped in Earths gravitational pull and accredited into our moon,which would account for traces of ice under the Moons regolith(top layer of 'soil').This theory is pretty much believed true,and I agree.
3.Our moon formed side by side with the Earth from the initial accretion of the sol. system.

Theory two is 95% likely,especially because the moons crust is very similar and identical in some respects with ours.

Hope that helped!

[edit on 4/10/2009 by jkrog08]

reply to post by jkrog08


Great!

[tin foil hat on]

On a conspiracy theory side, i thought that the moon is last final plan
of the illuminati - the all seen "eye" of the piramid could be the moon,
and since their actions all always shown before but people cant see because of all manipulation, the eye is the moon and the moon is
filled with aliens.... who controls them!



[tin foil hat off]


Who knows?


[]´s
RP


[edit on 10-4-2009 by RobertPaulsim]

[edit on 10-4-2009 by RobertPaulsim]

reply to post by RobertPaulsim


LOL,I don't know about that!

Very nice thread, thanks for taking the time and effort to put it together.

Was expecting to see Pluto listed as a planet but im glad it isnt

Alright,for all you Pluto lovers out there I have compiled a few photographs of the dwarf planet as well a comparison picture of sizes of planetoids in relation to Earth and Luna(our Moon).
Here is the best resolution NASA has been able to get of a true color picture of the dwarf.....

Pluto is mostly brown. This picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. No spacecraft has yet visited this most distant dwarf planet in our Solar System. The above map was created by tracking brightness changes from Earth of Pluto during times when it was being partially eclipsed by its moon Charon. The map therefore shows the hemisphere of Pluto that faces Charon. Pluto's brown color is thought dominated by frozen methane deposits metamorphosed by faint but energetic sunlight. The dark band below Pluto's equator is seen to have rather complex coloring, however, indicating that some unknown mechanisms may have affected Pluto's surface

See bottom of post for source of this and all pictures.
Here is an artist rendering with moon Charon(pretty good right?).....



Here is a comparison of some major planetoids......






space.about.com

[edit on 4/10/2009 by jkrog08]

reply to post by jkrog08


Have you ever tryed "Celestia" ?

Its a great software... and free. You can use the cursors and simulate
a starship... see the planets and all, even zoom out of the milky way..

I sometimes turn everything all lights off and go full screen....

If a starship sim is what you're after, this is the best imho:
orbit.medphys.ucl.ac.uk...
You're confined to the solar system for the moment (save for "jump drive" add-ons and extra solar system add-ons). Still, they have all kinds of spaceships and starships to play with:
www.orbithangar.com...
www.orbithangar.com...
www.orbithangar.com...
It's a great way to learn the physics of interplanetary travel too.

[edit on 10-4-2009 by ngchunter]

reply to post by ngchunter


Also a good way to crash into the ISS while hopelessly out of control.

reply to post by jkrog08


Congrats for putting out a whole bunch of information that is sorely needed!!!

Perhaps NOW we who understand these concepts can direct people's attention to THIS thread....I just need to learn how to do the linky thingy...

Good, informative thread.

Like you, I always wondered how so many people knew so much about aliens, their types, their names, known associates, aliases, and all this . . . stuff.

I wouldn't know a reptilian from an escapee from Uranus. I'm sorry but every time I see that name, I snicker.

Seriously, it would appear that a lot more is known about these aliens than Uranus. Sorry. . . Did it again.

And all without photos, interviews, autopsies (which would be required if I was ever approached by an alien), or any tangible proof at all.

Interesting thread, and I find our own solar system to be a constant wonder.

Good work.

reply to post by dooper


That's why we now pronounce the name of the planet as 'Your-an-ass'

OK...badly formed joke....really, the prefereed pronounciation is Ur-en-us.

Emphasis on the first syllable.

Ok, back to our regularly scheduled entertainment.....

In regards to our moon, it's interesting to note that it is actually larger than many of the Dwarf planets - meaning that by some measures, our Moon/Earth system is a dual-planet system based on size and density. However, it's only ever considered a moon because the barycenter of gravity between the two objects is well inside of the Earth's crust.

Also, Sedna has a roughly 12,000 year orbit around the sun - reaching well over 900+ Au at it's furthest distance... yet still well within the Oort Cloud.

reply to post by Lasheic


Thanks, Lasheic, for mentioning the 'dual planet' concept....I'd mentioned it on another thread, it's good to be verified!

As to the Earth-Moon system....the current scientific analysis is that the smaller body (that's the Moon) is gradually, with each orbit, spiralling farther away. At this time, is is about 3 cm/year. A billion years ago, when the Moon was closer, the center of mass of the Earth-Moon system would have been deeper under the Earth's crust than it is today...the combined effect of the 'dance' of the celestial bodies is a perfect example of the Law of conservation of momentum.

Imagine an ice-skater, spinning. She pulls her arms in close to her body, she spins faster....she changes her angular momentum by spreading her arms outward, she slows down...arms in, speed up, arms out, slow down...

This is a small-scale, real-world example that I hope people can understand. It is, of course, an oversimplification of celestial mechanics, but it helps to provide a mental image for people to grasp.... I hope.

Very cool and informative thread

One thing I find interesting is that Pluto has the biggest moon relative to it's host in the solar system, Charon is about half as big as Pluto. With the next largest being the Earth & Luna pair.

I have a question regarding the order of the planets, rocky planets in the inner solar system followed by the gaseous planets. Then there's the rocky planetoids. Do you think they formed in that order or is it more likely that they formed in the inner ss and then flung out to the outer ss?

Thanks, S&F

reply to post by ngchunter


WOW,I didn't know about that sim.Now you've just gave me yet another reason(besides ATS) to stay glued to the computer!lolThanx for the links.

I wish to personaly applaude the creator of this thread,, adn alll the info ...i myslef an am amateur astronomer, been into astronomy since i was 11, im going on 34 now. I once did a report in 8th grade so good, the shcool added my report, to their library. again, this was outstandingly done!!!!
I did notice notice, about Venus. Venus rotates in retrograde(west to east) and rotates in about 243 days to make one full rotation.
This should be star and flagged! hell! archive it!!

reply to post by yizzel

have a question regarding the order of the planets, rocky planets in the inner solar system followed by the gaseous planets. Then there's the rocky planetoids. Do you think they formed in that order or is it more likely that they formed in the inner ss and then flung out to the outer ss?

"Another factor in the development of the four inner terrestrial planets and the outer gaseous planets was temperature. After the protoplanets had formed, the central regions of the solar nebula were collapsing and forming the Sun, as described in Module 2. The young Sun caused the temperature of the closer inner protoplanets to be higher than the outer protoplanets. As a result, the kinetic energy of the gaseous molecules was too high for them to coalesce, and they simply dissipated. At the outer planets, however, the molecules were cold, and were moving slowly enough for gravity to overcome their movement. Over the course of several million years, the planets grew into the planets we know today. "

physicsforums.com

As far as the planetoids..........they are just 'leftovers' to far and to small to do really anything,or as some theorize remnants of a planetary collision in the primordial solar system.

It is odd though because we have found many exosolar planets with Jupiter sized planets in a Mercury range orbit.The explanation for them being gas giants is that they were pulled towards their star somehow(either due to lack of terrestrial planets,star mass,or close passes with other objects).Lol,I was trying to remember my professors explanation for your question but couldn't so I just looked it up for you(it's late here).



[edit on 4/10/2009 by jkrog08]

reply to post by ziggy1706


Thank you,I too love astronomy(obviously,lol) as well as cosmology and physics(theoretical mainly).Do you have a telescope?

reply to post by jkrog08


jkrog....many kudos for an excellent thread!!!

About the exosolar planets so far discovered that show a planetary system that is so different than what we are accustomed to, here in OUR Solar System.

These Star systems that have been observed depend, so far, on the ability to see the 'wobble' of the star in question, and to infer from the observations the mass and rotational period of the body causing the star's 'wobble'.

I entertain the possiblilty of many, many star system configurations....not all of them conducive to life, of course.

The accuracy of our observational techniques will continue to improve, given enough time.....