I though this to, but then I might have confused myself. ie for my object, at Critical spin, the surface of the primary is traveling at 2.28 m/s. BUT escape velocity is 3.28 m/s. At the surface Fg = 0.00706 m/s^2. So when I spin fast enough for Fc = 0.00706, The surface object is traveling...
Hi all,
I have a gravitationally bound rubble pile asteroid. This asteroid reaches and exceeds 'critical' spin where centripetal force exceeds gravitational force and surface material is launched off the surface.
At what minimum initial velocity would the surface material need to be to...
I hope you aren't referring to photographic plates - there is no accurate means of comparing them to CCD images. Measuring a stars brightness is based on comparisons with other stars - standard stars. BUT how standard are the standard stars? Everything is moving, everything evolves and all...
I was taught that this was not the case, that absorbed light would be retransmitted in the same direction just at a different wavelength otherwise this absorption would account for Olbers paradox! I apologise if I have misunderstood or misinterpreted the above statement.
From Wiki...
My math is not good and I will not pretend to follow your calculations but did any of it take into account Earth's gravity pulling back on the asthenosphere?
Cheers
David
Well any of Nabeshin's suggestions will likely be of little use if m~ray is actually interested in Planetary Astronomy! Or maybe he is trying to use his own bias to lead m~ray down a yet, undisclosed path... Is there something wrong with Planetary Science? (FYI my observational interest is in...
I believe the gravitational effect on light was first observed in 1919 during a solar eclipse (3 years after Eienstien predicted it) when the position of stars near the edge of the eclipsed disc of the sun were measured and found to move is a curved path aroudn the disc as the sun moved in front...
I'm not in a position to argue whether it should or shouldn't be used or how much impact the addition will have, I simply stated that it was used. The published ephemeris are simply used to calculate current positions and are not used for long term predictions.
Some people (and not sure if...
OK, so the whole issue is my 'understanding'/'use' of Orbit (and yes in hindsight it was an incorrect use of the term). I am a layman so was using it in reference to the 'moon' changing it's place in reference to the 'Earth's' surface and thus its impact on tides. And I dare say my use of...
My only reference is correspondance I have seen from those making the calculations (MPML group). I am certainly not arguing the scale of effect.
(Note that they - MPC, NEODys etc - do plot the orbits of these objects out to 100 years in the future - sometimes more to make collision...
There is no "no" about it. NEO's and Comet orbits have this applied. Why? because when we calculate the probability of collisions with Earth we want to know exactly where these objects are going to be.
Cheers
David
Did you read my definition of mutually tidally locked? Is that what you think is wrong? If the moon (not our moon) and the hyperthetical Earth (not our earth) were locked such that the moon showed the same face to the Earth and the Earth showed the same face to the moon then the moon is acting...
1. The moon still orbits the Earth (~28 days), its spin has been tidally locked - its not mutual. Note that my understanding of mutual here is that the moon presents the same face to Earth and the Earth would present the same face to the moon ie they are synchronised.
2. I was simply...
OK, granted that nothing is 'perfect' as in Pluto and Charon can be considered to be tidally locked though it's not a perfect system. This system is impacted by other objects in orbit. e = 0.0022 is still very small, an 0.4% variation from a circular orbit.
BUT these are barycentre orbital...
There is no eccentricity of orbit, the moon and Earth are tidally locked to each other ie neither is orbiting the other - consider them a single 'object' spinning on a axis that is the barycentre of the system.
Do you mean the effect the sun may have on the individual components of this system...