@divegeester saidThe tidal effect of the Sun has on the Earth is much smaller than the tidal effect of the Earth has on the its moon. If it wasn't for the Moon orbiting the Earth and the fact that the Earth would probably be absorbed into the Sun when the Sun turns into a red giant, the Earth would eventually become tidally locked with the Sun but that process would take MANY times longer because the tidal effect the Sun has on the Earth is much smaller.
It’s quite fascinating that our Moon is in tidal lock and presents the same face to the Earth constantly now.
But why isn’t the Earth in tidal lock with the sun?
@humy saidThank you.
The tidal effect of the Sun has on the Earth is much smaller than the tidal effect of the Earth has on the its moon.
I believe that the sun’s effect on the tides is approximately 50% that of the moon’s.
Is there a disconnect then between the effect of the sun on the water of the seas, and the effect of the sun on the land mass?
@divegeester
How did you arrive at that 50% number? It is a bit late, almost 1 AM for me so I don't want to do it but I do see the difference in distances is roughly 400 to 1, a quarter million miles to the moon V near 100 million miles to the sun so 400 squared would be about 160,000ths of the gravitation of the sun V the moon if they were equal in mass. But difference in mass is roughly 7 orders of magnitude.
Not sure where that leads me. But at a distance of very roughly 500,000 miles from center of mass of the sun the escape velocity of the sun is about 390 miles per second and at 1 AU, the escape velocity of the sun is roughly 24 miles per second.
That seems to line up with the inverse square law. Not sure where THAT leads me either. Too fricking late to think right now😉
@sonhouse saidWell I found this illustration of tides:
@divegeester
How did you arrive at that 50% number? It is a bit late, almost 1 AM for me so I don't want to do it but I do see the difference in distances is roughly 400 to 1, a quarter million miles to the moon V near 100 million miles to the sun so 400 squared would be about 160,000ths of the gravitation of the sun V the moon if they were equal in mass. But difference in ...[text shortened]... the inverse square law. Not sure where THAT leads me either. Too fricking late to think right now😉
http://scienceprimer.com/lunar-and-solar-tides
There is a graph showing the tides due to Luna and tides due to Sol and if the graph is to be believed it shows the solar influence looking like about 50% of Lunar. They don't talk about that aspect though..
Here it is in more detail and is says indeed Lunar tides are twice that of Solar tides but the solar tides varies as the moon circles Earth so it is a monthly quantity.
https://phys.libretexts.org/Bookshelves/University_Physics/Book%3A_University_Physics_(OpenStax)/Map%3A_University_Physics_I_-_Mechanics%2C_Sound%2C_Oscillations%2C_and_Waves_(OpenStax)/13%3A_Gravitation/13.07%3A_Tidal_Forces
@sonhouse saidThe Sun is approximately 27,000,000 times more massive than the moon and exerts 50% less tidal force than the Moon. However my question is related to the Sun’s tidal influence on the Earth vs the Earth’s tidal influence on the Moon, not the Moon on the earth.
Well I found this illustration of tides:
http://scienceprimer.com/lunar-and-solar-tides
There is a graph showing the tides due to Luna and tides due to Sol and if the graph is to be believed it shows the solar influence looking like about 50% of Lunar. They don't talk about that aspect though..
Here it is in more detail and is says indeed Lunar tides are twice that ...[text shortened]... -_Mechanics%2C_Sound%2C_Oscillations%2C_and_Waves_(OpenStax)/13%3A_Gravitation/13.07%3A_Tidal_Forces
The tidal force of the Earth on the Moon is about 20 times stronger than the tidal force of the moon on the earth. So can we then deduce from that, that the Sun’s tidal pull on the Earth vs the Earth’s pull on the Moon is therefore way out of my understanding...but here’s some physics I found on the net which apparently explains that it is very complicated and just as much to do with planetary diameters as well as distances and mass.
https://astronomy.stackexchange.com/questions/31984/why-isnt-earth-tidally-locked-to-the-sun
@divegeester
So one question I should be able to answer but can't right now (I was Apollo tech)
is were seismometers put on the moon. I think so but not sure. Well a quick google search says apollo 11 got one, Buzz Aldrin did that one and 5 more, but the first one only ran a few weeks before it died. The others were able to run for about 5 more years.
So the question in my mind, with some 20 times the tidal force on the moon V moon on Earth, how does that affect seismic activity on the moon?
Never saw much in the way of data there but they did say what data they have said something about the internal structure of the moon, but that is all they said.
Of course there is no water to slosh around like on Earth but still, with 20 X the tidal power it would seem to me there would be constant seismic activity unless all the shifting over billions of years left everything locked up tighter than a drum.
I found this about lunar seismic activity:
https://www.space.com/moonquakes-moon-is-shrinking-apollo-data.html
It seems Apollo sensors recorded up to richter 5 level shallow quakes and hundreds of very deep ones, hundreds of miles under the surface, they say due to Earth tides.
They also got a lot of analysis from Lunar reconnaissance orbiter showing scarps and such.
It seems the moon is still an active planet seismically speaking.
I wonder what effect that will have on future settlements on the moon? A 5 scale quake could rattle things up quite a bit.
I wonder how they calculated that 20X effect? The difference in mass is 4 times as great, Earth about 80 times more massive than the moon. Why isn't the tidal force then 80 times that of the moon?