Author Topic: 10 Scientific Reasons Why Our Solar System Is Really Weird  (Read 1608 times)

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #30 on: August 27, 2019, 04:14:19 AM »
Oh, no.  Here's the earth and moon to scale, including distance:


And here's Pluto and Charon to scale, including distance:


Although to be sure, not to the same scale as each other.  Charon is much more massive relative to Pluto than the Moon is relative to the Earth.  The barycenter of the Earth/Moon system is 1700km below the surface of the Earth; that of Pluto and Charon is almost 1000km above Pluto's surface, in space: the two bodies very much orbit each other.  In the Earth/Moon system, the Earth is absolutely the dominant body.

While I'm thinking of it, let's put everything but the sun to the same scale:


Yes, all the planets could fit between the Earth and the Moon.  No, it's probably not a good idea to put them all there.  :)

Pluto isn't a planet...
Atheist born, atheist bred.  And when I die, atheist dead!

Offline trdsf

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #31 on: August 27, 2019, 04:30:08 AM »
Pluto isn't a planet...
Dwarf planet.  Even so, Charon is much more massive relatively speaking to its primary.  Even moreso are the binary Trojan asteroids Patroclus and Menoetius, which are nearly the same size as each other at 125 and 112 km, respectively.  Their barycenter is just about halfway between them.

The point is, the Earth's Moon is only the largest natural satellite any terrestrial planet in our system has.  It's neither the largest natural satellite, nor is it the largest satellite relative to it's primary.  The guy in the video was trying to assert that there's something really weird about our moon, and he just doesn't have either the justification to think so, or the data to suggest so.  If we should start getting data from exosystems that suggest Earth-sized worlds don't often have Moon-sized moons, then he can make the assertion with some modicum of justification.  Otherwise, he's on the same ground as the people who saw that Venus was cloud-covered, and "deduced" that it must be a wet jungle world with dinosaurs.
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #32 on: August 27, 2019, 04:53:02 AM »
Dwarf planet.  Even so, Charon is much more massive relatively speaking to its primary.  Even moreso are the binary Trojan asteroids Patroclus and Menoetius, which are nearly the same size as each other at 125 and 112 km, respectively.  Their barycenter is just about halfway between them.

The point is, the Earth's Moon is only the largest natural satellite any terrestrial planet in our system has.  It's neither the largest natural satellite, nor is it the largest satellite relative to it's primary.  The guy in the video was trying to assert that there's something really weird about our moon, and he just doesn't have either the justification to think so, or the data to suggest so.  If we should start getting data from exosystems that suggest Earth-sized worlds don't often have Moon-sized moons, then he can make the assertion with some modicum of justification.  Otherwise, he's on the same ground as the people who saw that Venus was cloud-covered, and "deduced" that it must be a wet jungle world with dinosaurs.

I think I missed the point of this discussion somewhere.  I think the Earth's Moon has had profound affects on Earth and the development of life on it that are not the same as on Pluto's moons or any rotating asteroids.  Possibly some moons of other planets have sufficient water and heat through gravitational tidal friction or possibly even core heat to support some sort of life. 

What is this argument about? 
Atheist born, atheist bred.  And when I die, atheist dead!

Offline Baruch

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #33 on: August 27, 2019, 07:52:53 AM »
Tides.  On a water planet.  Are tides important?  Weak moons make for weak tides.
Ha’át’íísh baa naniná?
Azee’ ła’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't to that.

Offline trdsf

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #34 on: August 27, 2019, 04:05:49 PM »
I think I missed the point of this discussion somewhere.  I think the Earth's Moon has had profound affects on Earth and the development of life on it that are not the same as on Pluto's moons or any rotating asteroids.  Possibly some moons of other planets have sufficient water and heat through gravitational tidal friction or possibly even core heat to support some sort of life. 

What is this argument about?
I'm not entirely sure.  My original point was only that the video was incorrect in assuming there's something special about our moon.

In the first place, we know nothing about the moons of other Earth-sized planets in the galaxy, and in the second place, the only thing it has to recommend it is its proximity.  It has no ocean like Europa, Enceladus, or Ganymede.  It has no atmosphere, weather, or methane lakes like Titan.  It has no volcanism like Io or cryovolcanism like Triton.  It has no ring as has recently been theorized for Saturn's moon Rhea.

It's just a lump of mostly mantle with nothing special about it other than it happens to be our satellite.

Now, you're quite right that it's almost certainly had an important role in both abiogenesis and evolution.  The tidal effects alone -- and the moon was a LOT closer then -- kept the water circulating, brought it in contact with the shores to pick up chance minerals, moved countless random chemical experiments around from the safety of a few meters down in water to the catalytic violence of the surface with its lightning and ultraviolet radiation and heat and a heady proto-organic atmosphere of hydrogen and water and ammonia and methane.

It's supposed that it also helps keep our axis of rotation stabilized, but I'm not sure how unstable they think our daily rotate would be without it.  I mean, other than Uranus, the other seven planets are more or less aligned to a vertical that's not far off that of the sun.  Three cheers for conservation of angular momentum, I guess.

But none of that says that we have a special moon.  We just have the moon that we have, and until we have data on the natural satellites of other terrestrial bodies in the galaxy, we can draw no inferences about its "weirdness".
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline Baruch

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #35 on: August 27, 2019, 07:15:23 PM »
Yes, it is special.  Has its own book.  "Goodnight Moon …"
Ha’át’íísh baa naniná?
Azee’ ła’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't to that.

Offline Sal1981

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #36 on: August 27, 2019, 07:28:39 PM »
All great scientists seem to fins a really bad idea and defend it to their deaths.  The idea that we should have been visited by aliens by know is one of those.  There are sevela objects that come easily to mind.

1.  Non interference.  IOW, don't bother any planet with at least pond scum that can't talk "interstellar" yet.
2.  Hide while observing.  We can fool ducks with camoflauge.  "They" could do it better.
3.  Hide in open sight.  I might be an alien observing all of you for trends toward insterstellar threats.
4.  We're the first.  Someone has to to be.
5.  We're the last.  And stupidest.  Someone has to be.
6.  No one found us.  It's a VERY big Universe.
7.  Everyone creates their own universe where they are alone.  Proof me wrong.
8.  The Borg or the Q killed all the others and do (or do not) know about us yet.
9.  They read our superhero comic books and scared to death of us.  Don't laugh, that was a comic book plot once.
10.  We are on the wrong channel.  1420 to 1720 MHzis the interstellar PBS channel and no one "out there" actually watches it.

I could go on...
I'm partial to #4, myself. We may well be the first life to achieve intelligence.
Considering how long it takes for complex & intelligent biological life to form a galactic civilization, and how young, comparatively speaking, our universe is then we are probably the first on the field in our neck of the woods. If the same can occur around red dwarfs, for instance, it will happen a lot of times. We're an outlier in any case.
"The first principle is that you must not fool yourself - and you are the easiest person to fool" --- Richard P. Feynman

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #37 on: August 27, 2019, 10:23:39 PM »
Tides.  On a water planet.  Are tides important?  Weak moons make for weak tides.

Thank you. That clarified things.  Really.
Atheist born, atheist bred.  And when I die, atheist dead!

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #38 on: August 27, 2019, 10:30:15 PM »
I'm not entirely sure.  My original point was only that the video was incorrect in assuming there's something special about our moon.

In the first place, we know nothing about the moons of other Earth-sized planets in the galaxy, and in the second place, the only thing it has to recommend it is its proximity.  It has no ocean like Europa, Enceladus, or Ganymede.  It has no atmosphere, weather, or methane lakes like Titan.  It has no volcanism like Io or cryovolcanism like Triton.  It has no ring as has recently been theorized for Saturn's moon Rhea.

It's just a lump of mostly mantle with nothing special about it other than it happens to be our satellite.

Now, you're quite right that it's almost certainly had an important role in both abiogenesis and evolution.  The tidal effects alone -- and the moon was a LOT closer then -- kept the water circulating, brought it in contact with the shores to pick up chance minerals, moved countless random chemical experiments around from the safety of a few meters down in water to the catalytic violence of the surface with its lightning and ultraviolet radiation and heat and a heady proto-organic atmosphere of hydrogen and water and ammonia and methane.

It's supposed that it also helps keep our axis of rotation stabilized, but I'm not sure how unstable they think our daily rotate would be without it.  I mean, other than Uranus, the other seven planets are more or less aligned to a vertical that's not far off that of the sun.  Three cheers for conservation of angular momentum, I guess.

But none of that says that we have a special moon.  We just have the moon that we have, and until we have data on the natural satellites of other terrestrial bodies in the galaxy, we can draw no inferences about its "weirdness".

Please don't get upset if I claim you just made my argument for me.  But you probably did it better than I could/did.  I will add, though, that our moon has also stabilized our axial tilt and I don't think other moons have done that for their planet.  Otherwise, we might be like Mars tilting a lot more unseasonably.

I would suggest that no other moons came from the planet they orbit, but I can't actually prove that (proof of a negative and all that).
Atheist born, atheist bred.  And when I die, atheist dead!

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #39 on: August 27, 2019, 10:35:29 PM »
I'm partial to #4, myself. We may well be the first life to achieve intelligence.

Considering how long it takes for complex & intelligent biological life to form a galactic civilization, and how young, comparatively speaking, our universe is then we are probably the first on the field in our neck of the woods. If the same can occur around red dwarfs, for instance, it will happen a lot of times. We're an outlier in any case.

Yeah, I was out on a stretch there.  But sometimes brainstorming is useful.  It's not my usual thought pattern, but occasionally creative thought brings good discussion.  It's possible, but time isn't the best determinant for us.

I would ask why you think "probably" about us being first intelligence.  We aren't the oldest solar system, after all.
Atheist born, atheist bred.  And when I die, atheist dead!

Offline trdsf

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #40 on: August 28, 2019, 11:10:28 AM »
Please don't get upset if I claim you just made my argument for me.  But you probably did it better than I could/did.  I will add, though, that our moon has also stabilized our axial tilt and I don't think other moons have done that for their planet.  Otherwise, we might be like Mars tilting a lot more unseasonably.

I would suggest that no other moons came from the planet they orbit, but I can't actually prove that (proof of a negative and all that).
The only point I'm making is not that our moon can't be unusual, but that we don't know what is and isn't unusual for planets like the Earth.  You can't make meaningful judgments based on a single data point.  Until we have a better idea what is and isn't common in stellar systems, it just is what it is: an observation without any context to judge it.

Now, I do happen to think that life bearing planets will be more likely than not to have a moon capable of driving meaningful tides because I think that's important to the process of abiogenesis.  But I don't have any justification to call that anything more than a proposal, or even just a guess.  We can't look to Venus to confirm that because there appear to be other reasons life couldn't get started there.  Finding life -- past or present -- on Mars would be a data point against. I'm not sure that finding life on Europa, Enceladus or Titan would be relevant since those are completely different processes in action there.  Life there, however simple, would be staggeringly important for its own reasons.
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline Cavebear

Re: 10 Scientific Reasons Why Our Solar System Is Really Weird
« Reply #41 on: August 31, 2019, 02:42:02 AM »
The only point I'm making is not that our moon can't be unusual, but that we don't know what is and isn't unusual for planets like the Earth.  You can't make meaningful judgments based on a single data point.  Until we have a better idea what is and isn't common in stellar systems, it just is what it is: an observation without any context to judge it.

Now, I do happen to think that life bearing planets will be more likely than not to have a moon capable of driving meaningful tides because I think that's important to the process of abiogenesis.  But I don't have any justification to call that anything more than a proposal, or even just a guess.  We can't look to Venus to confirm that because there appear to be other reasons life couldn't get started there.  Finding life -- past or present -- on Mars would be a data point against. I'm not sure that finding life on Europa, Enceladus or Titan would be relevant since those are completely different processes in action there.  Life there, however simple, would be staggeringly important for its own reasons.

OK, I undertand that.  I could be possible that a sizable moon like ours might not even be necessary for life to arise in the ocean.  Hydrothermal vents might have well provided the original conditions instead of tidal pools (I make no decision about that now). 

But we do have a large moon and life arose here.  And there are consequences of a large moon that seem beneficial for life and evolution.  I also agree that is not proof of a large moon assisting causing life to exist on Earth.  But absent proof, corrlation is a starting point.

If and when we find a planet similar to Earth with a similar moon (which I suspect will not be a very common event) and there is or is not life (in the least degree of development), that would be some bit of evidence for or against the idea that a moon is required.

More will be better, and I suspect that improved instrumentation will allow us to answer that question in the next decade or 2.
Atheist born, atheist bred.  And when I die, atheist dead!