4 ms·
A piece of extraplanetary mass being brought to Earth only changes the planet's orbit insofar as its orbit on entry to Earth mismatches that of rest of the plan
by ravel-bar-foo 6y ago
A piece of extraplanetary mass being brought to Earth only changes the planet's orbit insofar as its orbit on entry to Earth mismatches that of rest of the planet. Furthermore, it will only slow down Earth's orbit if it was initially slower in the orbital direction, which means it would have to originate from the inner solar system.
Now, the retrieval of such mass to earth is (physically) an inslastic collision. Inellastic collisions usually dissipate energy, so the thermodynamic problem of overheating the Earth's atmosphere will be an issue before orbital changes or spontaneous nuclear fusion.
- justin66 6y ago> A piece of extraplanetary mass being brought to Earth only changes the planet's orbit insofar as its orbit on entry to Earth mismatches that of rest of the planet. No, the Earth’s orbit would also be affected over time by the altered gravitational relationship with other bodies as a result of its increased mass.
- saagarjha 6y agoAt that point it would cease to be a recognizable “Earth” and be more of a sort of protostar.
- justin66 6y agoJ6 floated an idea like that above, but a less drastic outcome where the earth takes on some very small fraction of one percent of additional mass, and the shape of its orbit merely changes a tiny bit, is also a possibility.
- ravel-bar-foo 6y agoGood point. That's a second-order effect I had not considered. However, orbital mechanics being what it is, that would not result in the Earth "sinking into the sun," which is the claim I was responding to.