If a comet kicks the moon out of its orbit and away from earth

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Discussion Overview

The discussion revolves around the hypothetical scenario in which a comet displaces the Moon from its orbit around Earth. Participants explore the potential effects on Earth's rotational axis and gravitational interactions, considering both immediate and long-term consequences.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether the displacement of the Moon would alter Earth's rotational axis.
  • Another participant suggests that the absence of the Moon would destabilize Earth's axis, but emphasizes the potential debris from a collision as a more significant concern.
  • A different viewpoint introduces the idea of a foreign celestial body grazing the Moon, proposing that while this might alter the Moon's orbit, it would not immediately affect Earth's rotational axis due to the lack of torque in this scenario.
  • This participant also discusses the long-term effects on Earth's axial precession, suggesting that a higher orbit for the Moon would weaken gravitational interactions and slow precession.
  • Another participant posits that without the Moon, Earth might move closer to the Sun due to changes in gravitational forces between the Earth and the Sun.

Areas of Agreement / Disagreement

Participants express differing views on the consequences of the Moon's displacement, with no consensus reached on whether or how Earth's rotational axis would be affected. Multiple competing hypotheses are presented regarding gravitational interactions and orbital dynamics.

Contextual Notes

Participants acknowledge the limitations of their assumptions, particularly regarding the size and impact of celestial bodies involved in the scenario, as well as the complexities of gravitational interactions.

redphoton
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If a comet kicks the moon, or any celestial object for that matter, out of its orbit and away from the earth, would it alter Earth's rotational axis?
 
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The Earth's axis would become less stable without the moon, but I would think that the bigger problem would be debris from the collision. I mean, that would be an enormous collision. Even the largest comet discovered so far is less than 1/1000 that of the moon.
 
redphoton said:
If a comet kicks the moon, or any celestial object for that matter, out of its orbit and away from the earth, would it alter Earth's rotational axis?

As DaleSpam points out, comets aren't large enough.

let's introduce a foreign body. Let's say a celestial body that was ejected from another solar system happens to fly right through our Solar system. Let's say that celestial body doesn't collide with the Moon, but just grazes it, resulting in a case of gravitational assist. (I'm guessing that a gravitational assist is the most efficient energy transfer. In a collision much of the energy would dissipate.)

I don't think such a gravitational assist can be vigorous enough to release the Moon from the Earth-Moon system, but it could alter the Moon's orbit significantly.

There would not be any immediate effect on the Earth's rotational axis. To change the direction of angular momentum of an object a torque must be exerted, and no such torque is present in this scenario

For a long term effect: the precession of the Earth's axis is due to gravitational interaction with the Sun and the Moon. If the Moon is lifted to a much higher orbit then the gravitaional interaction with the Moon will be weaker, resulting in an overall slower precession than the current precession.

Cleonis
 
I feel Earth will start moving towards the sun. because the moon has the influence over the Earth gravity. when you say there is no moon it sure alters the sun and Earth attractive force also.
 

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