[evgen]

Where do you think the "gravitational pull of the earth" ends? Hint: the moon is inside the gravitational pull of the earth... The danger is that things in orbit have velocity. A lot of velocity. Taking that nice F=mv^2 equation in mind you can imagine what would happen if a piece of space junk were to hit something we care about (or hit something we don't care about and create a lot more little pieces of junk that are now spreading out to cause more mayhem.) Space is big, and earth orbit is also a very big place, but there is still a lot of junk whizzing around up there and increasing the odds that something you forgot about will hit something you care about is counter-productive.

[greenhouse_gas]

Just to emphasize: There is no limit to the earth's gravitational pull. The formula is F=G*sqrt(m1m2)/r^2.

So as r (the distance between the center of the earth and your satellite) increases, F decreases. But it never hits zero.

Though after a while (a Sun-Earth L point, is it?), the influence of the sun will be greater (by orders of magnitude) than the earths.

[liuhenry]

For most interplanetary missions, Earth's gravitational pull on spacecraft can be modeled as a sphere of influence of about 1 million km.

https://en.wikipedia.org/wiki/Sphere_of_influence_(astrodyna...

[tajen]

I wonder as well what is the zone he’s talking about, but he talked about the zone in 9m/s2, not F=mv^2. I guess the first one extends up to 100km altitude, where I think geostationary satellites are, and indeed is very closeby.

Edit : Low earth orbit is 180+km, for weather satellites because they revolve in 99 minutes. Geostationary orbit seems to be around 36000km with a speed of 3000m/s. https://earthobservatory.nasa.gov/Features/OrbitsCatalog/