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RocketGator
2007-Feb-10, 04:49 AM
What if Jupiter managed to get just enough mass to begin fusion and became a red dwarf? What would it look like from Earth? Would it've messed up the formation of Earth or life on Earth?

Also, if Jupiter somehow suddenly gained the mass and ignited now, what would that do to us?

daxloves
2007-Feb-10, 05:21 AM
I am no expert but I would assume Jupiter would require allot more mass than is available to it in order to attain such mass so I don't think it could become a red dwarf. But if it did, Jupiter would appear to be a large bright star in the sky, the size depending on the amount of mass it acquired.
Judging from some of the giant gas planets we have found in other systems I think it will take a lot! But again, if it did and was of sufficent size the ignition it self would be enough to jostle some planets around and dangerously alter the orbits of many bodies in the asteroid belt between Jupiter an us.
If Jupiter was of sufficent size it's gravity would most likely effect all objects in our solar system. The sun itself would probably begin to wobble more and more as it began to be pulled by Jupiter's new massive gravity and would no longer be at the center of our solar system. So yeah, I think it would mess us up a little, if it were possible.

But like I said. I aint no expert. Don't take my word for it.

The Backroad Astronomer
2007-Feb-10, 05:22 AM
well the luminosity of a red dwarf is about 10^-2 as mauch as the sun so jupiter would be brighter but we would not effect much heat, as for messing up the formation of the Earth would not have much effect but life on Earth may different because it may of gone on a different evolutionary track without the as many asteroids hitting the Earth.

The Backroad Astronomer
2007-Feb-10, 05:45 AM
ok mass of jupiter relative to the mass of the sun=.001
mass of red dwarf to mass of sun=.08
so you would need 79 more jupiters to get to the mass of a red dwarf and there is actually not that much matter left in solar system so it would have of been during formation of solar system.
so actually depends on the initial conditions in the cloud that made the solar system what would happened.

RalofTyr
2007-Feb-10, 06:28 PM
Bye, bye Mars. You're getting ejected.

And the Dinosaurs would still be around to view the slightly brighter red dot in the sky.

RocketGator
2007-Feb-13, 10:21 PM
Bye, bye Mars. You're getting ejected.

Why would it kick Mars out? I thought bodies had to pass fairly close to be tossed out of the system.


And the Dinosaurs would still be around to view the slightly brighter red dot in the sky.

How bright?

Also, would Red Dwarf Jupiter's moons be habitable? For the sake of argument, assume the Galilean satellites did form around a RDJ.


so you would need 79 more jupiters to get to the mass of a red dwarf and there is actually not that much matter left in solar system so it would have of been during formation of solar system

That, I understand. I meant the 'Jupiter suddenly becomes a red dwarf now' just as a thought experiment, like the 'what if the Sun because a black hole' stuff.

DuaneW
2007-Feb-13, 11:38 PM
"Also, would Red Dwarf Jupiter's moons be habitable? For the sake of argument, assume the Galilean satellites did form around a RDJ."

I'm sure Jupiter glowed like a small star when it first formed, which removed most, if not all, surface water from the Galilean satellites. If Jupiter had in fact formed as a red dwarf, the Galilean satellites would perhaps have pleasant temperatures, but they would be bone dry.

RalofTyr
2007-Feb-14, 06:34 AM
Why would it kick Mars out? I thought bodies had to pass fairly close to be tossed out of the system.

I read somewhere that Mars stands a chance of getting ejected out of the solar system due to Jupiter. If Jupiter was more massive, this would speed the process up. Or Jupiter could send Mars inward. Perhaps it would miss Earth and luckly, get trapped by Venus as a moon. Imagine that. Due to tidal stress, Venus probably would be a very volcanically active world, whereas Mars would look nothing like it does today, having plate techtonics now. It would have a thicker atmosphere and probably liquid water.




That, I understand. I meant the 'Jupiter suddenly becomes a red dwarf now' just as a thought experiment, like the 'what if the Sun because a black hole' stuff.

Well, I was thinking realistically.





"Also, would Red Dwarf Jupiter's moons be habitable? For the sake of argument, assume the Galilean satellites did form around a RDJ."

I'm sure Jupiter glowed like a small star when it first formed, which removed most, if not all, surface water from the Galilean satellites. If Jupiter had in fact formed as a red dwarf, the Galilean satellites would perhaps have pleasant temperatures, but they would be bone dry.

If Jupiter glowed like a small star, then why are most of the Galilean Satellites made of ice and rock. Surely now, they should be bone dry worlds.

Kaptain K
2007-Feb-14, 09:44 AM
Or Jupiter could send Mars inward. Perhaps it would miss Earth and luckly, get trapped by Venus as a moon.
Ain't gonna happen. A "two body capture" is not possible.

Ronald Brak
2007-Feb-14, 10:20 AM
Ain't gonna happen. A "two body capture" is not possible.

Mars, Venus, the sun. Doesn't that count as more than 2 bodies? Not that I think venus could capture something as massive as mars, but there are plenty of smaller objects that have been captured by planets in our solar system.

Inferno
2007-Feb-14, 09:20 PM
Someone been reading 2010?

Kaptain K
2007-Feb-14, 11:40 PM
Mars, Venus, the sun. Doesn't that count as more than 2 bodies?
Not in the sense we're talking about here. The Earth could capture Mars, losing the Moon in the process or Mars could capture the Moon from Earth. Venus could capture Mars if one of them had a moon the size of Ceres to lose.

DaveC426913
2007-Feb-15, 02:05 AM
Jupiter undergoing fusion would be much more than a bright red dot.

1] At its current size, it is a visible disc. With the required mass, it would be significantly larger.

2] Currently, as a mere planet that shines by reflected light alone, it still manages to outshine everything in the night sky save the Moon. As a small red sun, it will look to us like a small red sun.

Kaptain K
2007-Feb-15, 07:36 AM
With the required mass, it would be significantly larger.
Sorry, but Jupiter is near the maximum diameter for a planet or brown dwarf star. From 1 Mj (Jupiter) to 100Mj (red dwarf star), the diameter is almost constant.

RocketGator
2007-Feb-15, 05:17 PM
So, to summarize:

1. Less junk in the inner solar system.
2. Mars gets punted inward and smashes into Venus, giving Venus a large moon like ours.
3. The Galilean satellites will be drier, but might have habitable temperatures. Would 2010 and 2061 be reasonable descriptions of RDJ satellites?
4. RDJ would be about the same size from Earth, but will cast a dim red glow at night. We wouldn't get much, if any, heat from it.

Would that mess up stargazing while RDJ's up if it's a red light?

Matherly
2007-Feb-15, 06:23 PM
J2] Currently, as a mere planet that shines by reflected light alone, it still manages to outshine everything in the night sky save the Moon. As a small red sun, it will look to us like a small red sun.

Someone please correct me if I am wrong, but I thought Venus was brighter.

Ronald Brak
2007-Feb-16, 03:34 AM
Not in the sense we're talking about here. The Earth could capture Mars, losing the Moon in the process or Mars could capture the Moon from Earth. Venus could capture Mars if one of them had a moon the size of Ceres to lose.

Very interesting. So how did mars capture its first moon if there were only two bodies involved? (I realise the answer may actually be hideously complicated.)

gGriffeth
2007-Feb-16, 03:47 AM
Someone please correct me if I am wrong, but I thought Venus was brighter.
Me too?

Kaptain K
2007-Feb-16, 05:36 AM
So how did mars capture its first moon if there were only two bodies involved?
Why do you assume there were only two bodies involved? Binary asteroids are not unknown.

Ronald Brak
2007-Feb-16, 06:34 AM
Why do you assume there were only two bodies involved? Binary asteroids are not unknown.

So for mars to capture its moons they must have originally been binary asteroids? Okay, so how did these binary asteroids form?

Kaptain K
2007-Feb-16, 07:12 AM
So for mars to capture its moons they must have originally been binary asteroids? Okay, so how did these binary asteroids form?
Collisions. If a large "parent body" is hit hard, many chunks can be blown off at (or in excess of) escape velocity. If two bodies have similar enough ejection velocities (speed and direction), they can wind up as a binary system.

Ronald Brak
2007-Feb-16, 07:29 AM
Okay, so collisions can make binaries and one of a binary pair can be captured. So the captured asteroids of mars and other planets were all presumably member of binary pairs to begin with. So do all captured asteroids show signs of big impacts in the past? But then I guess most asteroids do. I have another question which may or may not be silly. If an asteroid broke apart under the right circumstances as it approached a planet, could part of it be captured or would it still count as a two body situation?

Thanks for the effort you have put into answering my questions.

Kaptain K
2007-Feb-16, 09:06 AM
So the captured asteroids of mars and other planets were all presumably member of binary pairs to begin with.
emphasis added

The major moons of the giant planets are thought to have formed at the same time as the planets. So, these planets have a "built in" multi-body capture system.

Ronald Brak
2007-Feb-16, 09:31 AM
The major moons of the giant planets are thought to have formed at the same time as the planets. So, these planets have a "built in" multi-body capture system.

Okay, so a planet that started with at least one moon could end up with a collection of captured asteroids without losing the satellites it started with, while a planet with no moons could only capture asteroids that were members of binary pairs. I think I've got it.

closetgeek
2007-Feb-16, 02:12 PM
Hey, when I was irritating everyone with my endless spew of questions, trying to understand why Jupiter wasn't a red dwarf, it had nothing to do with 2010. I enjoyed the movie, but my questions came as a result of an article I was reading about binary star systems.




Someone been reading 2010?

neilzero
2007-Apr-26, 10:34 AM
Red dwarf Jupiter would not be much larger with it's mass increased 100times. Perhaps 2000 times the volume of Earth.
Red dwarf Jupiter would always be brighter than Venus, but a deep red color with just barely enough mass to support nuclear fusion. Jupiter occasionally appears brighter than Venus.
The capture theory may be flawed, as a massive third body is needed to capture an asteroid. In most senarios placement is very critical and improbable.
Moons and planets typically survive the protostar phase with loss of surface volitiles. Later volatiles seep to the surface from deep in the interior, with the help of volcanoes. Neil

cbacba
2007-Apr-26, 08:54 PM
A few tidbits. Telescopes were becoming fairly reasonable devices before mar's moons were discovered. The technique used to spot them visually pretty well existed back then (around newton's time) . Was it the author of gulliver's travels postulated mars had a couple of moons in his writings at that time? It would have been a feather in someone's cap to have announced the discovery. I suppose some ATM or conspiracy type could postulate newton actually discovered them but was so much into being a veritable hermit (ticked off due to his encounters with hooke, or whatever) that he never even wrote it down or reported it.

An alternative to this would be that perhaps the moons weren't there during newton's time. Due to the existance of the telescope and the fascination with planets, it would seem that some sort of mars surface event might draw attention between newton's time and when the moons were discovered (1877 by hall). As such, it would seem they would probably have been captured, refugees from the asteroid belt perhaps. Of course it's possible too no one used an eyepiece with an eclipsing bar? to view mars in search of moons.

As for stars, there are brown dwarfs smaller than red dwarfs. I seem to recall reading that jupiter actually emits more energy than it receives from the sun - of course not by much.

Perhaps in a few million or billion years, especially if we go through any dense star forming regions, jupiter may eventually suck up lots more matter until it finally reaches sufficient mass to become a brown dwarf or perhaps even a red dwarf. Suffice to say that after 5 billion yrs, it's only gotten this far so don't hold your breath or place large bets on it.

Hornblower
2007-Apr-26, 10:29 PM
If Proxima Centauri, an extremely faint red dwarf, were at Jupiter's distance from us, it would be comparable to the full Moon in brightness, but concentrated into a dazzling point of light as seen with the unaided eye. It would be roughly the color of Mars or Betelgeuse as indicated by its published photographic color index. That would be more of a pale orange than a deep red. (Astronomers tend to use the term "red" rather loosely here.)

phaishazamkhan
2007-Apr-26, 11:01 PM
Perhaps it would miss Earth and luckly, get trapped by Venus as a moon. Imagine that. Due to tidal stress, Venus probably would be a very volcanically active world, whereas Mars would look nothing like it does today, having plate tectonics now.

Plate tectonics? Heck, these planets would have a magnetosphere and poles and all that from all that churning magma. Screw plate tectonics, get these bodies a a protective magnetic field!


Ain't gonna happen. A "two body capture" is not possible.

Why not just "highly improbable"?

RalofTyr
2007-Apr-28, 07:24 AM
Mars has a lot of oblong craters were, quite possible, captured asteroid that were once moons like Phobos and Demos fell into Mars. Mars is a moon eater.

antoniseb
2007-Apr-28, 06:59 PM
Mars is a moon eater.
You are speculating as to the cause of something, and stating it as fact. It is OK to say something like this here IF you make it clear that you are speculating. BTW, can you please show some images of these oblong craters you speak of? None are coming to mind when I think of images from the Mars orbiters. Also, can you say what kind of trajectory would cause an oblong crater of some given eccentricity? Further, can you say why it would have to be a moon to come in at such an angle?

EDG
2007-Apr-28, 11:05 PM
Mars has a lot of oblong craters were, quite possible, captured asteroid that were once moons like Phobos and Demos fell into Mars. Mars is a moon eater.

It's more likely that they were just asteroids that came in at low incidence angles (you thinking of things like Orcus Patera?). While they may have been 'captured' for a while as their orbits decayed (like Shoemaker Levy 9 around Jupiter), that doesn't really qualify them as bona-fide "moons".