Supernova Detonation Aimed at Earth? Astronomers Say "Maybe"

[chequita guevara]

No, I just expected you to make a snarky comment about me saying that Poly makes me smarter.

[KrazyHorse]

Was that a preemptive strike?

So yes.

[Berzerker]

I have some questions for you brainiacs

Why dont the planets orbit the Sun's equatorial plane? The Earth is ~7 degrees off the plane I think

Why does our Moon orbit ~5 degrees off The Earth's equatorial plane?

Why do Saturn's rings point to Pluto at its perihelion?

Why do Saturn and Pluto ascend the ecliptic so close together?

How could Jupiter form before, and get big enough to disrupt the formation of inner planets?

Do the asteroids form a plane, ie the asteroids have more inclined orbits so do they form a disc of debris tilted to the Sun's equatorial plane and does this disc of debris point to any planets?

Is there a website with asteroid orbital data that uses the Solar equatorial plane rather than the ecliptic? I'd like to see if there is any pattern to the "slope" of the asteroid belt, they appear to be in more inclined orbits in the outer sections of the belt and less inclined toward the inner belt.

[KrazyHorse]

I have some questions for you brainiacs

Why dont the planets orbit the Sun's equatorial plane? The Earth is ~7 degrees off the plane I think

Why do you expect that all these objects should rotate EXACTLY in the right plane? 7 degrees is a pretty low number.

Is there a website with asteroid orbital data that uses the Solar equatorial plane rather than the ecliptic?

if you know the inclination and azimuth of both then figuring out the relative inclination is a very simple exercise in spherical trigonometry.

[KrazyHorse]

Like, literally 2 lines of code simple given a library with inverse trig functions

[Berzerker]

Why do you expect that all these objects should rotate EXACTLY in the right plane? 7 degrees is a pretty low number.

looking at the Galilean moons I'd expect equatorial orbits for the planets within a degree or two. And another thing, the Galileans are spaced like the inner planets would be if the Earth was moved to the asteroid belt. Well, not exactly but they'd be close to a 1:2:4:8 ratio.

if you know the inclination and azimuth of both then figuring out the relative inclination is a very simple exercise in spherical trigonometry.

If I had spherical trig in school I probably failed



I have another question(s): astronomers say the Earth was probably struck by something the size of Mars, how did the Earth stay in its orbit? Wouldn't the release of all that energy slow us down and move us closer to the Sun?
If the Earth was hit here, why dont we see debris trails following a similar orbit rather than a debris trail leading back to the asteroid belt which we do see?

Apparently we now have evidence the Earth had oceans (or an ocean) 4.4 bya but virtually all evidence of that time was wiped out by an impact ~ 4 bya, so we start seeing many more rocks (and life forms) from ~3.9 bya. The Moon appears to have been hit by a wave of debris ~ 4 bya. Were we hit twice by massive objects? Once about 4.5 bya to form the Moon and again 4 bya? I believe this second impact is why the Moon is off kilter.

[chequita guevara]

[Q=Berzerker;5573525]I have some questions for you brainiacs

Why dont the planets orbit the Sun's equatorial plane? The Earth is ~7 degrees off the plane I think[/q]

With the exception of Mercury, most of the inner planets are aligned with Jupiter's orbital plane. That should be a no brainer, that over billions of years, Jupiter will tug everything more or less into alignment with it. Earth's furthest out of alignment cuz it got plowed into by another planet.

Why does our Moon orbit ~5 degrees off The Earth's equatorial plane?

The Earth wobbles.

Why do Saturn's rings point to Pluto at its perihelion?

Chance.

Why do Saturn and Pluto ascend the ecliptic so close together?

Chance.

How could Jupiter form before, and get big enough to disrupt the formation of inner planets?

Someone had to be first. And gas giants seem to be rather common in the galaxy so far. Everywhere we look, we find them.

Do the asteroids form a plane, ie the asteroids have more inclined orbits so do they form a disc of debris tilted to the Sun's equatorial plane and does this disc of debris point to any planets?

It's hard to ascribe a shape to something that is mostly empty. Gravitationally, the shapes the various asteroid fields take are shaped by Jupiter.

Is there a website with asteroid orbital data that uses the Solar equatorial plane rather than the ecliptic? I'd like to see if there is any pattern to the "slope" of the asteroid belt, they appear to be in more inclined orbits in the outer sections of the belt and less inclined toward the inner belt.

http://en.wikipedia.org/wiki/Asteroid_belt#Orbits_and_rotations

[KrazyHorse]

looking at the Galilean moons

???

Why the **** would you do that? The dynamics aren't likely to be the same. For example, the tidal forces on even the outermost of Jupiter's moons is 30 times larger than are the tidal forces on Mercury.

The fact that planets rotate somewhat in the plane of the sun's rotation is pretty obvious, but unless you're willing to dive deep into details I see no reason why you would expect 2 degrees rather than 7.

If I had spherical trig in school I probably failed

Let the inclination of the sun's rotation relative to the earth's orbit be theta1 and its azimuth be phi1. Let the inclination of a body's orbit relative to the earth's orbit be theta2 and its azimuth be phi2

The inclination of the body's orbit relative to the sun's plane of rotation is:

arccos(cos(theta1)*cos(theta2) + sin(theta1)*sin(theta2)*(cos(phi1)*cos(phi2) + sin(phi1)*sin(phi2)))

You have to be a little careful about the defined range of arccos in whatever programming language you use. (should be 0 to pi). You can also choose to rewrite

cos(phi1)*cos(phi2) + sin(phi1)*sin(phi2) = cos(phi1 - phi2) in the above.

[Berzerker]

[Q=Berzerker;5573525]I have some questions for you brainiacs

Why dont the planets orbit the Sun's equatorial plane? The Earth is ~7 degrees off the plane I think[/q]

With the exception of Mercury, most of the inner planets are aligned with Jupiter's orbital plane. That should be a no brainer, that over billions of years, Jupiter will tug everything more or less into alignment with it. Earth's furthest out of alignment cuz it got plowed into by another planet.

How did Jupiter get out of whack?

Why does our Moon orbit ~5 degrees off The Earth's equatorial plane?

The Earth wobbles.

Largely because the Moon is out of whack too, right? Aren't the Moon and Sun the 2 main factors in precession?

Why do Saturn's rings point to Pluto at its perihelion?

Chance.

Was it Einstein or Newton who said God doesn't roll dice with the cosmos? Rather peculiar we'd find what appears to be a fast spinning double planet ejected from the plane of the solar system lined up with Saturn's rings. And that aint all, they share almost identical ascending nodes and subtracting Saturn's distance from the Sun reveals a nice 2 to 1 ratio in Pluto's orbit.

Why do Saturn and Pluto ascend the ecliptic so close together?

Chance.

thats three

How could Jupiter form before, and get big enough to disrupt the formation of inner planets?

Someone had to be first. And gas giants seem to be rather common in the galaxy so far. Everywhere we look, we find them.

But gas giants need more time to form, they occupy a less dense part of the nebula and only balloon after the solar wind fuels them with volatiles from the inner solar system. Rocky inner planets aint gonna be disturbed by a Jupiter that hasn't formed yet. The freeze line is at the asteroid belt...another chance

Do the asteroids form a plane, ie the asteroids have more inclined orbits so do they form a disc of debris tilted to the Sun's equatorial plane and does this disc of debris point to any planets?

It's hard to ascribe a shape to something that is mostly empty. Gravitationally, the shapes the various asteroid fields take are shaped by Jupiter.

Jupiter is responsible for the Kirkwood Gaps but not the inclined orbits of the asteroids. If we look at the belt as a "ring" like that around Saturn, the slope of the ring wrt the Sun and Earth may tell us something important. That is, if there is a slope.

Is there a website with asteroid orbital data that uses the Solar equatorial plane rather than the ecliptic? I'd like to see if there is any pattern to the "slope" of the asteroid belt, they appear to be in more inclined orbits in the outer sections of the belt and less inclined toward the inner belt.

http://en.wikipedia.org/wiki/Asteroi..._and_rotations

Thx, I also found a minor planet website. I just need to make sure the orbital inclinations I'm looking at use the solar plane.

[KrazyHorse]

How did Jupiter get out of whack?

6 degrees = out of whack???

Also, you should note that if (and this is undoubtably a terrible assumption which nonetheless probably gets us in the right ballpark) the sun were a sphere rotating at a uniform rate (let's take that rate as once per 30 days) whose mass was evenly distributed through its volume the angular momentum of Jupiter w.r.t the center of mass of the solar system is significantly larger than that of the sun.



So it's the sun which is "out of whack" with Jupiter, rather than the other way around.

[KrazyHorse]

Quick calc:

omega_sun/omega_jup = 150
m_sun/m_jup = 1000
r_sun/d_jup = 1/1000

The last factor gets squared, and overall there's a factor of 2/5 from the moment of inertia of a solid sphere. This naive calc gives L_sun/L_jup = 0.06

[chequita guevara]

[Q=Berzerker;5574012]How did Jupiter get out of whack?[/q]

Who says Jupiter is out of whack? Why, because reality isn't all neat and tidy? Look, back in the early days of the Solar system, there were a lot of planets flying around. Some of them got eaten, some of them got kicked further out of the solar system, and some were flung out of the system altogether (some probably fell into the sun, also).

Keep in mind that the original protoplanetary disk wasn't as thin as a sheet of paper, so some objects formed above and below the solar equator.

Largely because the Moon is out of whack too, right? Aren't the Moon and Sun the 2 main factors in precession?

No, the Moon actually acts like a gyroscope, and tames the Earth's wobble down. Without the Moon, Earth would tumble.

Was it Einstein or Newton who said God doesn't roll dice with the cosmos? Rather peculiar we'd find what appears to be a fast spinning double planet ejected from the plane of the solar system lined up with Saturn's rings. And that aint all, they share almost identical ascending nodes and subtracting Saturn's distance from the Sun reveals a nice 2 to 1 ratio in Pluto's orbit.

It was Einstein. Anyway, you got any evidence that Pluto's orbit matches Saturn's? Every description of Pluto I've ever heard is that it is a Kuiper Belt object that got pulled in by Neptune.

thats three

So, there are billions of seemingly random events that came together to create the now.

But gas giants need more time to form, they occupy a less dense part of the nebula and only balloon after the solar wind fuels them with volatiles from the inner solar system. Rocky inner planets aint gonna be disturbed by a Jupiter that hasn't formed yet. The freeze line is at the asteroid belt...another chance

Do they need more time to form? And we know that in other star systems, the gas giants are close in. Neptune migrated out, as did Uranus.

[Lancer]

I think Uranus should be renamed. Saying a simple thing like 'Uranus is migrating' is just too distracting for teenagers in high school.

[Dinner]

Uranus is big.

[Lancer]

I'm bored, when does the disaster flick come out? I hope Rachel Weisz is in it as the brilliant but sexy astronomer who falls in love with the G man who whisks her off to Cheyenne mountain where they have a love affair while the Earth is microwaved on SuperDuper setting for two minutes and afterward they go out to repopulate the planet fade to black.