Is it possible to move a planet out of its orbit? At least a lighter planet?
As observed by many researches our sun will be exhausted in the distant future. So does anyone think that driving our planet (or any planet) closer to the sun for more light and heat is a solution for life to survive on earth? Or would moving it out of the sun's gravitational field and taking it to some other solar system with a healthy star be better, possibly with some kind of thrusting mechanism that we may invent in future?
I am aware of the sun's gravity and the mass of the earth.
First the Sun will actually keep getting hotter and expand, so we still would need to move the Earth, but outwards.
It is necessary for long term existence of life on Earth. And it is difficult for advanced life to leave Earth, we are adapted to its atmosphere, minerals and biosphere which are complicated to recreate. It might be easier to move the Earth than to build a mini-copy of its environment.
Yes. Even with todays technology we can get started.
In this article by Korycansky et al 2001 it is suggested to use rockets to move an asteroid (like a larger version of the NASA ARM Asteroid Redirect Mission) to a cycling orbit between Earth and Jupiter. The asteroid would pass near infront of the Earth in order to give the Earth a slight gravity assist which moves it outwards. The asteroid then passes near behind Jupiter to itself get a gravity assist. This transfers energy from Jupiter's to Earth's orbit. I've also heard of a proposal to use Venus instead.
The paper says: "Our initial analysis shows that the general problem of long-term planetary engineering is almost alarmingly feasible using technologies that are currently under serious discussion. The eventual implementation of such a program, which is moderately beyond current technical capabilities, would profoundly extend the time over which our biosphere remains viable." This conflicts with you saying that we could get this started with today's technology. We could start planning it maybe. You could stand to clarify this a little.
It will only take one _slight_ miscalculation and the asteroid will ram into Earth, successfully ending the silly mission of a deluded race of organisms to move their planet outside. Another type of miscalculation would have the asteroid fall into Jupiter or one of its moons. Or _our_ moon could come collide into Earth. Or our moon could detach from us forever and get shot outwards, or into the sun. Silly little wishful humans ...