Starship Asterisk*

Why is the dust "indirect evidence of a destructive planetary collision" and not direct evidence that dust can't form planets around close binary stars?

jimmysnyder wrote:Why is the dust "indirect evidence of a destructive planetary collision"
and not direct evidence that dust can't form planets around close binary stars?

The Poynting Robertson effect perhaps

http://apod.nasa.gov/apod/ap080925.html

http://en.wikipedia.org/wiki/When_Worlds_Collide

When worlds collide; now there's an old sifi flick I haven't seen for quite a while.

Orin

Ironically,Ironically, this indirect evidence of a destructive planetary collision could also be the first indication that planetary systems can form around close binary stars.

Without any irony a fact of presence of dust and collisions of planets of this binary system can not be "the first indication that planetary systems can form around close binary stars" That is absurdity.
The planets are formed beside single stars only, having nearly circular orbit around center of galaxy, for which the parameters of planetary niches are unchangeable (see http://bourabai.kz/wind-e.htm for time of order of trillion years.

The truth in discussionned text is very probable fact of destruction of planets at collision in connection with breach of stability of planetary niches.

orin stepanek wrote:http://apod.nasa.gov/apod/ap080925.html

http://en.wikipedia.org/wiki/When_Worlds_Collide

When worlds collide; now there's an old sifi flick I haven't seen for quite a while.

----------------------------------------
The Pool Guy
http://www.seinfeldscripts.com/ThePoolGuy.html

KRAMER: Jerry, don't you see? This world here, this is George's
sanctuary. If Susan comes into contact with this world,
his world's collide. You know what happens then?

(Kramer raises his hands into the air and slowly brings them
together in an explosion. He's holding some food in one hand,
so when his hands come into contact food flies all over)

KRAMER: Ka shha shha shha Pkooo (exploding sound)
...........................................
GEORGE: You know what's going to happen now?

JERRY: World's collide. (points at George)

GEORGE: Whe ... Well yeah!

JERRY: Because this world is your sanctuary and if that world comes into
contact with --

GEORGE: YES! It Blows Up! So if you know that, what did you tell
Elaine for?

JERRY: I didn’t know. Kramer told me about the worlds.

GEORGE: You couldn't figure out the “World's Theory” for yourself? It's
just common sense. Anybody knows, ya gotta keep your worlds apart.
(gesturing with hands going outward)

JERRY: Yeah, I guess I slipped up.

(Kramer enters)

KRAMER: Hey.

GEORGE: Hey.

JERRY: Hey.

GEORGE: He knows the worlds theory.

KRAMER: What is it blowing up?

GEORGE: Ha! (grabs his coat and exits the apartment)
----------------------------------------

So if the Earth were to collide with another heavenly body, are we hoping to be in the basement, tied to an anvil or something? Is the Earth's atmosphere held to the Earth by gravity?

kdeck wrote:So if the Earth were to collide with another heavenly body, are we hoping to be in the basement, tied to an anvil or something? Is the Earth's atmosphere held to the Earth by gravity?

Yes, the atmosphere is held in place by gravity.

Anvil or roof top, it's completely your choice which pose you take before being vaporized.

Dr. Skeptic wrote: Yes, the atmosphere is held in place by gravity.

Anvil or roof top, it's completely your choice which pose you take before being vaporized.

I'll take the rooftop. I'd like to see where I'm going, even if it's just for a split nanosecond.

I always take a look at the APOD and enjoy it. With regards to today's image, "When Worlds Collide", I wonder why if we are to speculate about the origin of the dust in the system that we would imagine an /Earth/-like planet being destroyed. It could have been a relatively "dead" world, like Venus or Mars, or something else entirely. I am not religious, but I do believe there are higher forces in Nature that would work to prevent the destruction of a rare, jewel-like Earth. Perhaps this illustration may be a projection of the fears we have for our /own/ planet.

kdeck wrote:

Dr. Skeptic wrote: Yes, the atmosphere is held in place by gravity.

Anvil or roof top, it's completely your choice which pose you take before being vaporized.

I'll take the rooftop. I'd like to see where I'm going, even if it's just for a split nanosecond.

--------------------------------
Bart's Comet
http://www.simpsoncrazy.com/scripts/barts-comet.php
..........................................
BART: (looks into the telescope) Hey... (presses "redial" on the phone) Hello, observatory? This is Bart Simpson. I see something weird in the sky at 4-12-8 and the last number is 7.

WOMAN: (on phone) Congratulations, Bart. You've just discovered a comet.
..........................................
LISA: Don't you realize what's happening, Bart? Your comet is going to collide with the Earth and every living thing in its path will be killed!

BART: I knew you'd try to find something wrong with my comet, Lisa. You've always been petty and small, right from the beginning.

HOMER: What's everyone so worked up about? So there's a comet, big deal. It'll burn up in our atmosphere and what's ever left will be no bigger than a Chihuahua's head.

BART: Wow, Dad, maybe you're right.

HOMER: Of course I'm right. If I'm not, may we all be horribly crushed from above somehow. (everyone groans).

{The comet enters the atmosphere, breaking up.}

MARGE: Look!

LISA: It's breaking up!

{The comet breaks up more, until it becomes just a small rock. The rock makes a hole in Skinner's weather balloon, deflating it, then rebounds off Ned's bomb shelter, knocking it to the ground. Ned and Moe look on and gasp, while the comet bounces up the hillside. Bart picks it up.}

BART: Cool!

LISA: We're saved!

{Everyone cheers.}

SELMA: Sure makes you appreciate the preciousness of life. (lights a cigarette)

MOE: Let's go burn down the observatory so this'll never happen again.

{Everyone leaves, except for the Simpson family.}

LISA: I can't believe that extra-thick layer of pollution that I've picketed against is what burned up the comet.

BART: But what's really amazing, is that this is exactly what Dad said would happen.

LISA: Yeah, Dad was right...

HOMER: I know, kids. I'm scared too!

I think the 2 planets will start desagregate long before they hit each other. The gravity of each other will tear them apart. The 2 planets will take the shape of an oblong (My english aint that good to find the right word.) and start cracking. Lava will rush from everywhere and water from ocean will rush toward the other planet direction submerging all land drowning everything. So we will be all dead long before impact. I think. There might be unlucky survivor. Or lucky to saw how it end.

[quote="Karim Khaidarov
Without any irony a fact of presence of dust and collisions of planets of this binary system can not be "the first indication that planetary systems can form around close binary stars" That is absurdity. The planets are formed beside single stars only, having nearly circular orbit around center of galaxy, for which the parameters of planetary niches are unchangeable (see http://bourabai.kz/wind-e.htm for time of order of trillion years. The truth in discussionned text is very probable fact of destruction of planets at collision in connection with breach of stability of planetary niches.[/quote]

In contradiction, a recent article in New Scientist by Marcus Chown describes rcent work that has found the possibility both of planet formation and stable orbits around binary stars: http://space.newscientist.com/article/m ... f=top1_pic

The link is only to the NS website and a truncated version of the article. If I can retrieve it, and on request I will offer a precis. Meanwhile, there is evidence of planets in binary star systems: http://www.spaceflightnow.com/news/n0210/11planet/
and here are some theoretical stable orbits http://burtleburtle.net/bob/physics/binary.html

John

This APOD suggests the possibility of planets around binary star systems.



http://antwrp.gsfc.nasa.gov/apod/ap070730.html

My students asked why Earth was being destroyed, and then I said look at the continents, along with the sun(s)! I think the point is that it's an old system so there could have been a mature jewel like Earth. But in a binary? Are stable planetary orbits possible?

cmflyer wrote:My students asked why Earth was being destroyed, and then I said look at the continents, along with the sun(s)! I think the point is that it's an old system so there could have been a mature jewel like Earth. But in a binary? Are stable planetary orbits possible?

Pluto/Charon is a binary dwarf planet and yet it has two moons.


Haumea is elongated enough to effectively act like an binary dwarf planet (gravitation wise) and it has two moons.
http://apod.nasa.gov/apod/ap080923.html

DavidACaruso wrote:I always take a look at the APOD and enjoy it. With regards to today's image, "When Worlds Collide", I wonder why if we are to speculate about the origin of the dust in the system that we would imagine an /Earth/-like planet being destroyed. It could have been a relatively "dead" world, like Venus or Mars, or something else entirely. I am not religious, but I do believe there are higher forces in Nature that would work to prevent the destruction of a rare, jewel-like Earth. Perhaps this illustration may be a projection of the fears we have for our /own/ planet.

You don’t have to be religious to believe that Earth is destined for destruction.

Science tells us that cosmic objects have life cycles…
http://en.wikipedia.org/wiki/Formation_ ... lar_System
<<"In roughly 5 billion years, the Sun will cool and expand outward to many times its current diameter (becoming a red giant), before casting off its outer layers as a planetary nebula, and leaving behind a stellar corpse known as a white dwarf. In the far distant future, the gravity of passing stars gradually will whittle away at the Sun's retinue of planets. Some planets will be destroyed, others ejected into interstellar space. Ultimately, over the course of trillions of years, it is likely that the Sun will be left alone with no bodies in orbit around it.">>

neufer wrote:

cmflyer wrote:My students asked why Earth was being destroyed, and then I said look at the continents, along with the sun(s)! I think the point is that it's an old system so there could have been a mature jewel like Earth. But in a binary? Are stable planetary orbits possible?

Pluto/Charon is a binary dwarf planet and yet it has two moons.

http://en.wikipedia.org/wiki/Moons_of_Pluto

<<It is suspected that the Plutonian satellite system was created by a massive collision, similar to the "Big Whack" believed to have created the Earth's moon. In both cases it may be that the high angular momenta of the moons can only be explained by such a scenario. The nearly circular orbits of the smaller moons suggests that they were also formed in this collision, rather than being captured Kuiper Belt objects. This and their near orbital resonances with Charon suggest that they formed even closer to Pluto than they are at present, and that they migrated outward as Charon achieved its current orbit. If Hydra and Nix turn out to be tidally locked, as Charon is, that will settle the issue, as tidal forces are insufficient to damp their rotations in their present orbits. Both are a Lunar grey like Charon, which is consistent with a common origin. Their difference in color from Pluto, one of the reddest bodies in the Solar system due to the effects of sunlight on the nitrogen and methane ices of its surface, may be due to a loss of such volatiles during the impact or subsequent coalescence, leaving the surfaces of the moons dominated by water ice. Such an impact would be expected to create additional debris (more moons), but these must be relatively small to have avoided detection by Hubble. It is possible that there are also undiscovered irregular satellites, which are captured Kuiper Belt objects.

Nix and Hydra are very close to a 1:4:6 orbital resonance with the Charon-Pluto orbital period: Nix is within 2.7% of resonance, while Hydra is within 0.3%, though neither are in an exact resonance. It may be that these orbits originated as forced resonances when Charon was tidally boosted into its current geosynchronous orbit, and then released from resonance as Charon's orbital eccentricity was tidally damped. Today the Pluto-Charon pair continue to produce strong tidal forces, with the gravitational field at the outer moons varying by 15% peak to peak. At the lower estimated size range, Nix should have no significant precession, while Hydra should have a precession period of 15 years. However, at their maximum projected masses (assuming an albedo of 4%), the two moons may be in a 3:2 orbital resonance with each other, with libration periods of 400 to 450 days, though this may already be ruled out by the low eccentricity of Charon. Thus accurate orbital data can help resolve the sizes of these moons.

However, it was recently calculated that a resonance with Charon could boost either Nix or Hydra into its current orbit, but not both: boosting Hydra would have required a near-zero Charonian eccentricity of 0.024, while boosting Nix would have required a larger eccentricity of at least 0.05. They suggest instead that Nix and Hydra were captured and migrated inward until they were trapped in resonance with Charon.>>
-----------------------------------------------
____ Neptune resonances:
......................................................
Pluto: 3:2 orbital resonance with Neptune.
http://en.wikipedia.org/wiki/Plutino
http://en.wikipedia.org/wiki/Image:TheK ... _Polar.svg

Haumea: 12:7 orbital resonance with Neptune?
http://en.wikipedia.org/wiki/Image:TheK ... 03EL61.svg

Makemake: 11:6 orbital resonance with Neptune?
http://en.wikipedia.org/wiki/Image:TheK ... 005FY9.svg

Eris: 17:5 orbital resonance with Neptune?
http://en.wikipedia.org/wiki/Image:Eris_Orbit.svg

If Makemake is in 11:6 orbital resonance with Neptune, then
its orbital period is 60190d x 11/6 = 110348.33d = 302.11yr.

However, if its orbital resonance with Neptune were 15:8, then
its orbital period would be 60190d x 15/8 = 112856.25d = 308.98yr.

The figure of nearly 309 years is much closer to Makemake's actual
orbital period than just over 302 years. It's not clear why 11:6 is quoted
when 15:8 appears more accurate.

https://en.wikipedia.org/wiki/Makemake wrote:
<<Makemake (orbital period = 309.09 yr) is a classical Kuiper belt object, which means its orbit lies far enough from Neptune to remain stable over the age of the Solar System. Unlike plutinos, which can cross Neptune's orbit due to their 2:3 resonance with the planet, the classical objects have perihelia further from the Sun, free from Neptune's perturbation. Such objects have relatively low eccentricities and orbit the Sun in much the same way the planets do. Makemake, however, is a member of the "dynamically hot" class of classical KBOs, meaning that it has a high inclination compared to others in its population. Makemake is, probably coincidentally, near the 11:6 resonance with Neptune.>>

Timtin wrote:
If Makemake is in 11:6 orbital resonance with Neptune, then its orbital period is 60190d x 11/6 = 110348.33d = 302.11yr. However, if its orbital resonance with Neptune were 15:8, then its orbital period would be 60190d x 15/8 = 112856.25d = 308.98yr.

The figure of nearly 309 years is much closer to Makemake's actual orbital period than just over 302 years. It's not clear why 11:6 is quoted when 15:8 appears more accurate.

In fact, 15:8 is so much more accurate (0.05% vs. 2.27%) that one wonders if the author(s) of the Wikipedia article would have to rethink their argument that this is "probably coincidentally".

Hopefully one of you posts about these issues on the discuss page for the Wiki entry. That's how it gets fixed.

geckzilla wrote:Hopefully one of you posts about these issues on the discuss page for the Wiki entry. That's how it gets fixed.

https://en.wikipedia.org/wiki/Talk:Makemake#resonance