SLS weighs 10X Statue of Liberty...

[Anthony William Sloman]

On Monday, April 11, 2022 at 8:50:09 AM UTC+10, Phil Hobbs wrote:

John Larkin wrote:
On Sat, 9 Apr 2022 13:50:57 -0400, Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote:
On 4/8/22 1:21 PM, John Larkin wrote:
On Fri, 08 Apr 2022 19:12:39 +0200, Jeroen Belleman <jer...@nospam.please> wrote:
On 2022-04-08 17:55, jla...@highlandsniptechnology.com wrote:
On Fri, 08 Apr 2022 14:43:07 GMT, Jan Panteltje <pNaonSt...@yahoo.com> wrote:
On a sunny day (Fri, 8 Apr 2022 13:50:55 -0000 (UTC)) it happened Mike Monett <spa...@not.com> wrote in <XnsAE736426AB...@144.76.35.252>:

<snip>

The idea is to nudge a rock to swing past a bigger rock in the
asteroid belt. Do that a bunch of times and eventually swing an
asteroid in a hyperbolic loop past earth and transfer some momentum.
Do that for a million years or whatever.

That would take very little energy, just a good aim.

Nope. The main asteroid belt orbits are several times further out than
the Earth\'s, so you have to get rid of most of the asteroid\'s kinetic
energy if you want to get its angular momentum low enough for it to
reach the orbit of the Earth.

Wrong. You actually have to add enough kinetic energy to make the asteroid\'s orbit elliptical enough cross the orbit of the earth.

If you did it right, the asteroid will have the right sort of gravitational interaction with the earth to raise the earth into a slightly higher orbit.. while itself ending up in somewhat lower orbit, ready to do it again and again. You\'d need a super-Newton, or somebody with a lot of computer time to play with, to work out what you actually could do, but they probably they wouldn\'t start off thinking that they had to get rid of an asteroid\'s kinetic energy before they started the process

Even then, I seriously doubt there\'s enough mass in the asteroid belt to do much to the Earth\'s orbit.

This paper
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1743921315008388
claims that the main asteroid belt has a mass of 1.2E-9 of the Sun\'s.

The solar mass is 2E30 kg, so the asteroid belt\'s is 2.4e21 kg. The
Earth\'s is 6e24 kg, so the ratio of the total mass of the asteroid belt
to that of the Earth is

ratio = 2.4e21 kg / 6e24 kg = 0.0004.

One can do orbital mechanics till one is blue in the face, and never
figure out a way to make the Earth\'s orbit grow by an amount more than a
few times that 400 ppm number.

Put enough energy into making lots of asteroids make lots of passes around the earth, and the asteroidal mass could be used as a conveyer belt.

If you routed the asteroid orbits past Jupiter as well , you could presumably end up transferring some of it\'s orbital momentum to the Earth as well..

Jupiter would end up in a slightly lower orbit, but it wouldn\'t become a near earth object.

--
Bill Sloman, Sydney

 

[Jeroen Belleman]

Mike Monett wrote:

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
On Sat, 9 Apr 2022 13:50:57 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:
[...]

Nope. The main asteroid belt orbits are several times further out than
the Earth\'s, so you have to get rid of most of the asteroid\'s kinetic
energy if you want to get its angular momentum low enough for it to
reach the orbit of the Earth.

Even then, I seriously doubt there\'s enough mass in the asteroid belt to
do much to the Earth\'s orbit.

This paper
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/
S1743921315008388> claims that the main asteroid belt has a mass of
1.2E-9 of the Sun\'s.

The solar mass is 2E30 kg, so the asteroid belt\'s is 2.4e21 kg. The
Earth\'s is 6e24 kg, so the ratio of the total mass of the asteroid belt
to that of the Earth is

ratio = 2.4e21 kg / 6e24 kg = 0.0004.

One can do orbital mechanics till one is blue in the face, and never
figure out a way to make the Earth\'s orbit grow by an amount more than a
few times that 400 ppm number.

Cheers

Phil Hobbs

You also have to include the moon. This is needed to stabilize the Earth\'s
spin. [...]

I\'ve seen that stated many times, without anyone ever even explaining
why that should be so. So, why would the earth wobble without the moon?

Jeroen Belleman

 

[Mike Monett]

Jeroen Belleman <jeroen@nospam.please> wrote:

Mike Monett wrote:
[...]

You also have to include the moon. This is needed to stabilize the
Earth\'s spin. [...]

I\'ve seen that stated many times, without anyone ever even explaining
why that should be so. So, why would the earth wobble without the moon?

Jeroen Belleman

Gravity, orbits and nonuniform mass distribution of Earth.

1. \"The Moon: Required for Life on Earth\"
https://www.icr.org/article/moon-required-for-life-on-earth

2. \"Who Needs a Moon?\"
https://www.science.org/content/article/who-needs-moon

3. \"Earth\'s Stabilizing Moon May Be Unique Within Universe\"
https://www.space.com/12464-earth-moon-unique-solar-system-universe.html

4. \"The Past and the Future of the Earth-Moon System\"
https://www.wondriumdaily.com/the-past-and-the-future-of-the-earth-moon-
system/




--
MRM