Author Topic: Theia (Read 21722 times)

Andreas · « **on:** March 06, 2009, 12:46:17 PM »

Hey why not add a Theia-Protoearth Simulation into Universe Sandbox?

Andreas · « **Reply #1 on:** March 07, 2009, 10:38:53 AM »

For the ones here, who donÂ´t know what iÂ´m talking about:
Theia was a planet as big as mars, that crashed into earth 4,3 Billion years ago. A result of that Crash is the moon and earth tilt.

Chaotic Cow · « **Reply #2 on:** March 07, 2009, 11:22:45 AM »

could of just editted your last post.

BUT

Cool idea.

FGFG · « **Reply #3 on:** March 07, 2009, 04:47:04 PM »

we will return on the termodinamic, planet vs planet collision, hard to implement in Universe Sandbox bla bla bla...

However is avery cool idea: It would be so interesting collide 2 planets and watch if one or more moons will be created, or if the 2 planets will be totally destroyed

Naru523 · « **Reply #4 on:** March 11, 2009, 02:44:58 PM »

In Greek mythology, Theia, goddess or divine, (sometimes written Thea or Thia), also called Euryphaessa, wide-shining, was a Titaness. The name Theia alone means simply, "goddess"; Theia Euryphaessa (Θεία Εὐρυφάεσσα) brings overtones of extent (eury-, wide) and brightness.

In 1.d of The Greek Myths by Robert Graves, he relates that in the Pelasgian creation myth, she was the child of Eurynomeâ€”the creator called the goddess of all thingsâ€”who created Theia as a Titaness ruling the sun. The Pelasgian culture is identified by some as pre-Hellene or early Hellene. In 42.a Graves also relates that later Theia is referred to as the cow-eyed Euryphaessa who gave birth to Helius, the sun, in myths dating to Classical Antiquity.

Once paired in later myths, with her Titan brother Hyperion as her husband, "mild-eyed Euryphaessa, the far-shining one" of the Homeric Hymn to Helios, was said to be the mother of Helios (the Sun), Selene (the Moon), and Eos (the Dawn).

Pindar praises Theia in his Fifth Isthmian ode:

"Mother of the Sun, Theia of many names, for your sake men honor gold as more powerful than anything else; and through the value you bestow on them, o queen, ships contending on the sea and yoked teams of horses in swift-whirling contests become marvels".

She seems here a goddess of glittering in particular and of glory in general, but Pindar's allusion to her as "Theia of many names" is telling, since it suggests assimilation, referring not only to similar mother-of-the-sun goddesses such as Phoebe and Leto, but perhaps also to more universalizing mother-figures such as Rhea and Cybele.

In the sciences
Main article: Giant impact hypothesis

Theia's mythological role as the mother of the Moon goddess Selene is alluded to in the application of the name to a hypothetical planet which, according to the giant impact hypothesis, collided with the Earth, resulting in the Moon's creation.

Theia's alternate name Euryphaessa has been adopted for a species of Australian leafhoppers Dayus euryphaessa (Kirkaldy, 1907).

monmarfori · « **Reply #5 on:** March 11, 2009, 03:46:13 PM »

The giant impact hypothesis (sometimes referred to as the big whack, or, less frequently, the big splash) is the now-dominant[citation needed] scientific hypothesis for the formation of the Moon, which is thought to have formed as a result of a collision between the young Earth and a Mars-sized body that is sometimes called Theia.[1] Evidence for this hypothesis includes moon samples which indicate the surface of the moon was once molten, the moon's apparently relatively small iron core, and evidence of similar collisions in other star systems. Questions remaining to be resolved about this hypothesis include why lunar samples do not have ratios of volatile elements, iron oxide, or siderophilic elements which would be implied by this hypothesis, as well as what evidence may suggest the earth ever had the magma ocean implied by this hypothesis.

Andreas · « **Reply #6 on:** March 11, 2009, 05:48:13 PM »

We need Theia in Universe Sandbox.

The protoearth was posion and like venus. Without Theia, there would be no life. We can say, that theia sacrificed herself to create the world we know today.

So Dan should give her the late honor to be part in universe sandbox!

Theia!

Image source:
http://eltamiz.com/wp-content/uploads/2008/06/impacto-theia-tierra.jpg

Naru523 · « **Reply #7 on:** March 13, 2009, 08:02:35 PM »

WHOA.

space guy1 · « **Reply #8 on:** March 16, 2009, 12:30:52 PM »

actually if my logic is correct you should be able to do it now. what you would do is create a new system with just earth, stop all rotation,set collision to bounce,explode earth with a velocity of 0 until you get at least 300 pieces in a ball. Next add/subtract pieces until you get protoearth's mass, zero all velocity. create mars and fire it at earth with a similar direction and velocity as theia. Just before it hits create at least 300 theia pieces using above method. restart simulation. if you did it just right you should form a debris disk and protomoon eventually. the only problem with this method is you need a really fast computer.

Andreas · « **Reply #9 on:** March 21, 2009, 10:38:25 AM »

Thats not practical.

I donÂ´t want an after crash simulation. I want that Theia and Earth orbit the sun and after few orbits collide.
Their didnÂ´t hit earth frontal. Theia struck earth in 20Â° angle. Universe sandbox already create by such impacts "dust" that circle around the object.

Without any doubt was the meeting of earth and theia one of the most epic events in the history of our solar system

space guy1 · « **Reply #10 on:** March 21, 2009, 10:51:08 PM »

Quote from: Andreas on March 21, 2009, 10:38:25 AM

Without any doubt was the meeting of earth and theia one of the most epic events in the history of our solar system

id bet my life there was more impressive(how did Miranda get that way? how did Saturn's rings form?)

Andreas · « **Reply #11 on:** March 22, 2009, 02:44:51 AM »

Ha ha ha ha
Miranda is very small moon. That event is small event. Same about Saturns rings. A small Body with not even 300 Km diameter broke up. And?

But the collission of the mars sized planet Theia with earth is way over that. there were debris particles that were larger then miranda.

FGFG · « **Reply #12 on:** March 22, 2009, 08:40:38 AM »

Probably there were many other impacts like the one beetween Earth and Theia, in the solar system. One of the possible explanations for the opposite rotation of Venus is proper a big impact with another celestial object... quite big

Chaotic Cow · « **Reply #13 on:** March 22, 2009, 11:16:29 AM »

This thread made me wonder...

Why do we call Luna the Moon when it's name is Luna.

I mean I know Moon means Luna but I don't think there is anyone who calls it Luna.

monmarfori · « **Reply #14 on:** March 22, 2009, 03:33:19 PM »

but when xp default theme is luna
it should not be confused

monmarfori · « **Reply #15 on:** March 22, 2009, 03:34:12 PM »

http://en.wikipedia.org/wiki/Luna_(theme_)
or http://en.wikipedia.org/wiki/Moon

Andreas · « **Reply #16 on:** April 03, 2009, 12:40:09 AM »

Quote from: Naru523 on April 02, 2009, 07:33:51 PM

Quote from: Andreas on March 07, 2009, 10:38:53 AM
For the ones here, who donÂ´t know what iÂ´m talking about:
Theia was a planet as big as mars, that crashed into earth 4,3 Billion years ago. A result of that Crash is the moon and earth tilt.
If it was 4.3 billion years ago and the Earth formed 4.5 billion years ago, THERE should be a LARGE crater. So it's not 4.3 billion years.

i canÂ´t stand that anymore. How can there be a crater, when the entire earth got melted? The earth is liquid inside. The crust only few dozen km thick. The two planets fused. Theia wasnÂ´t an asteroid, it was a planet. The crust of earth was complety melted.

Why canÂ´t you even try to inform yourself, BEFORE you say something and place it as fact?! Ever heared about hydrostatic balance? Guess not...

FGFG · « **Reply #17 on:** April 06, 2009, 12:23:31 PM »

The first Earth (if I remember well, is named "Gaia", but you shouldn't trust me... ) was formed about 4.5 billions years ago... then, after 200 millions years (so 4.3 Billions years ago), probably another planet, called Theia, collided with Earth ==> The two planets exploded like two gelatine balls: the result was the Earth and the Moon as we know them now...

Andreas · « **Reply #18 on:** April 07, 2009, 06:35:47 AM »

Thats right

Naru523 · « **Reply #19 on:** April 07, 2009, 09:23:20 PM »

OK. (P.S. The name "Gaia" is right.)

FGFG · « **Reply #20 on:** April 08, 2009, 04:45:11 AM »

Dan Dixon · « **Reply #21 on:** April 10, 2009, 06:46:25 PM »

Quote from: Andreas on March 07, 2009, 10:38:53 AM

Hey why not add a Theia-Protoearth Simulation into Universe Sandbox?
For the ones here, who donÂ´t know what iÂ´m talking about:
Theia was a planet as big as mars, that crashed into earth 4,3 Billion years ago. A result of that Crash is the moon and earth tilt.

Great idea and something I've wanted to do for some time. When I work on improving collisions and explosions this most likely be my primary test case.

Quote from: space guy1 on March 16, 2009, 12:30:52 PM

actually if my logic is correct you should be able to do it now. what you would do is create a new system with just earth, stop all rotation,set collision to bounce,explode earth with a velocity of 0 until you get at least 300 pieces in a ball. Next add/subtract pieces until you get protoearth's mass, zero all velocity. create mars and fire it at earth with a similar direction and velocity as theia. Just before it hits create at least 300 theia pieces using above method. restart simulation. if you did it just right you should form a debris disk and protomoon eventually. the only problem with this method is you need a really fast computer.

Awesome. That exactly how I would have described how to do something like it now. Although you can set the number of pieces to something much lower and still get a satisfying result.