/sci/ - Science & Math

>>9740488
I think you meant switched positions?
Earth and Mars start orbiting their barycenter, and Earth's orbit around the Sun is probably fucked so we all die.
The Moon would be just fine, just a little colder.

>>9740499
>>>59711117
>switched orbits.

>>9740552
do you need a dictionary? are you lost? how do you "switch orbits" for two objects with different masses? they will have different orbits by definition

>>9740488
Does Mars also inherit the Moon's orbital velocity?
This is important.

If so, not a hell of a lot. Mars is about twice the size of the Moon so it will be considerably larger in our sky and it's quite a bit more massive so our barycenter will change, however Earth's distance to the Sun changes more throughout the year already so it won't have a massive impact (in the short term) to overall climate and such, the average will probably be roughly the same.
Tides will be affected, though.
Eclipses will be crazy.

>>9740565
Reading comprehension not your forté, is it?

The question posed in the thread referred to was on "switching orbits".

>how
Magic.
>by definition
I doubt there's a textbook out there that defines orbits for magically swapped planetary bodies. Asshat.

>>9740488
It'd be much more interesting if Venus and Mars switched. We'd potentially would have two live-filled planets within reach.

>>9740488
Earthquakes on both planets, and crazy weather on Earth.

>>9740565
>how do you "switch orbits" for two objects with different masses? they will have different orbits by definition
Ummmmm, no?
Now I'm not a huge fan of the "what if somehow (magic) something impossible happened" style of question, BUT....
Orbital speed doesn't depend on an objects mass or density.
If you magically switched Venus and Mars, aND swapped BOTH their position AND speed, both would orbit just fine.

In the Mars & Moon scenario:
>>9740499
>Earth and Mars start orbiting their barycenter,
Sure...
>>9740499
>and Earth's orbit around the Sun is probably fucked
Probably not. Assuming the Earth/Mars system has the same velocity relative to the Sun, we should keep the same orbit, regardless of the increase in mass.
The big difference would be the massive tides.

your question needs more specifics OP?

>>9740758
>if Venus and Mars switched. We'd potentially would have two live-filled planets within reach.
Venus might lose the runaway greenhouse effect,and who knows? But Mars would just likely be a warmer dead rock than it is now.

>>9740783
There is no better "terraformer" than life itself, once it reaches a critical number it will make any planet perfectly suited for more complex life.

>>9740794
Wow, you're going to get laid a LOT in college.
Shame you don't know shit about science, though.

>>9740780
>Orbital speed doesn't depend on an objects mass
Of course it does. However, we usually discuss a host body with a mass so much larger than orbiting bodies, that the differences are negligible.
Mars replacing the Moon is not a subtle difference.

Nothing would really happen as earth would only get slightly colder. However there would still be life forms in mars as the size/mass of a planet can affect the lifeforms living and as mars is the wrong size it still won't carry life forms.

Shit sorry, it's suppose to say "still be no life forms", in the second line.

Crazy fucking tides.

>>9741405
>Mars replacing the Moon is not a subtle difference.
Compared to the mass of the sun it is.
The Earth/Mars binary would orbit a t almost exactly the same distance as the Earth/Moon system.

And besides, let's REALLY split hairs. All the bodies in the solar system are orbiting their collective center of mass. Moving Mars closer to the center of the solar system isnn't going to change the location of the solar system's center
of mass.
We don't notice the effect of Jupiter being on the same side of the Sun as us vs the opposite side, and it's almost 3000 times the mass.

>>9740766
We already have both.
It'd be survivable.

would look pretty cool. But putting Jupiter there would look even better.

http://todayilearned.co.uk/2013/04/02/if-other-planets-switched-places-with-the-moon-this-is-what-you-would-see/

>>9741461
Neat, but I see they forgot Pluto.

>>9740780
>Assuming the Earth/Mars system has the same velocity relative to the Sun, we should keep the same orbit, regardless of the increase in mass.
no brainlet try again

more massive earth/mass system in the current earth/moon solar orbit would immediately decay into the sun. and by immediately i mean in a few thousands of years. the moon, if it was to take up mar's current orbit would immediately be ejected from the solar system, or at least into the outer planetary region where it might collide with or be captured by Jupiter, Saturn, or Neptune.

>>9741621
No.
So long as their inherit each other's orbital velocities their orbits would remain relatively the same.

Welcome to orbital mechanics. You are new here but there is a lot to learn. Go model it in Universe Sandbox or SpaceEngine.

>>9741621
>more massive earth/mass system in the current earth/moon solar orbit would immediately decay into the sun
I bet you think heavier objects fall faster too, huh?

>>9740580
>Tides will be affected, though.
>>9740780
>The big difference would be the massive tides.
Ok, I just realized we're overlooking something here.
The moon is getting farther away (very slowly) and IIRC the idea is the energy that drives the tides has to come from somewhere, and that 's accomplished by the moon perpetually moving to a lower energy orbit.
Mars should give us much larger tides. How would this impact the speed at which the two bodies get further apart?

>>9741675
Mars would move away faster, but it would still take a ridiculously long time to reach the relative size of the Moon currently.

>>9741653
>>9741671
>more massive objects dont require higher velocities to hold the same orbits as lower mass objects

inb4: an entire planet worth of mass is irrelevant

what would happen if we somehow absorbed mars into our orbit? not for collisions or anything, but assume it can safely orbit around earth much like the moon does now.

>>9741697
>>more massive objects dont require higher velocities to hold the same orbits as lower mass objects
You finally said something correct.

>>9741701
yeah whatever brainlet
V is dependent on both M1 and M2

>>9741707
shit. the mass of the planet cancels... never mind. fuck it at least I know how to solve the system

>>9741503
They used the IAU definition of "planet".

>>9741697
>inb4: an entire planet worth of mass is irrelevant
It's not irrelevant, it's just balanced by the inertia/centrifugal force pulling outwards.
Have you ever seen video of astronauts abord the ISS?
If you let an object (like a pen) float in the cabin, it doesn't suddenly slam into the wall because it's mass is less than that of the station itself.
Orbital speed relates to the radius of the orbit.
Jesus, just go Google it instead of posting your wrong answer over and over.

>>9741435
>Compared to the mass of the sun it is.
Oh lawd... I suppose I should have spelled that out:
The difference in mass between the Moon and Mars will have a large effect on the orbital speed of the newly introduced body (Mars) because I was talking specifically about the Earth-nowMars system, but I see that you were talking about the Sun-whatever system and you're right, there wouldn't be much of a difference as I pointed out when I said that we usually consider the host body being vastly larger... blah blah blah.
Got it?
ib4 your final insult, I'm not responding, so go ahead you've got the mic - you're not worth more of my time.

>>9742213
>ib4 your final insult,
Why would I resort to ad hominem?
You're still wrong, and you've hardly explained your point.
>>9742213
>The difference in mass between the Moon and Mars will have a large effect on the orbital speed of the newly introduced body (Mars)
No, it won't. Orbital speed is unrelated to the mass of the orbiting body.
And even if you weren't wrong, how would Mar's allegedly faster(?) orbit affect us?
And what I think is your first post asserts:
>>9740499
>Earth's orbit around the Sun is probably fucked so we all die.

Just either Google "orbital dynamics" or take our word for it, please.

>>9740794
Neither of those planets have a magnetosphere.

>>9742736
I wonder if proximity with Earth could kick start some activity in their cores.
Not saying I know the math, but the tidal forces would be considerable.

>>9742736
>Neither of those planets have a magnetosphere.
Yeah, and I keep hearing that's why Mars has no atmosphere.
OK, fine, but then why does Venus have one?

>>9742801
>OK, fine, but then why does Venus have one?
Just throwing this out there by maybe Venus lost its magnetosphere much later than Mars, it had a thicker atmosphere and has greater gravity, and these three things together result in the atmosphere it has now.