Comments on: Bouncing Laser Beams Off of the Moon http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html Chronicling and Commenting on Human Progress Fri, 12 Mar 2010 00:45:22 +0000 http://wordpress.org/?v=2.2 By: gerardo alvarez http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36591 gerardo alvarez Fri, 18 Dec 2009 22:53:54 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36591 Many thanks Anthony for your comprehensive and convincing answer. So it may be that reaching those metheorites under the bottom of the craters in the Moon, could be best way to learn about composition of unburned material from outer space, and eventually even find some remain of some eventual kind of space life?- Many thanks Anthony for your comprehensive and convincing answer.
So it may be that reaching those metheorites under the bottom of the craters in the Moon, could be best way to learn about composition of unburned material from outer space, and eventually even find some remain of some eventual kind of space life?-

]]> By: Anthony Kendall http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36573 Anthony Kendall Fri, 20 Nov 2009 01:34:23 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36573 Gerardo, To answer your questions, there are many large impact craters on the Earth's surface. If your very curious, check out Google Earth and search for impact craters. But, you're also right that there are many fewer on the Earth than the Moon. This is because of the two points you mentioned: atmospheric destruction of the incoming meteorite, erosion, and sedimentation. Those last two, in particular are responsible for most of the cover-up work of larger impacts. Take, for example, the Chixculub crater, which many scientists believe to have been caused by the impact which led to the extinction of the dinosaurs. That crater impacted in a shallow sea, and is completely invisible at the surface due to sedimentation filling in the crater, and erosion of upturned beds surrounding the crater's rim. Nevertheless, we can still tell it's there by looking for geologic clues like glass beads and certain other minerals. Another point to be made here is that the visible surface of the Earth hasn't been that way for long. With the exception of stable continental interiors, like the Canadian Shield, most of the Earth's surface is geologically young compared to the moon. While it's possible that the Moon migrated here from elsewhere in the solar system, there's good enough evidence about the mineral composition of the Earth's mantle and the Moon that we can infer their common origin. Gerardo,
To answer your questions, there are many large impact craters on the Earth’s surface. If your very curious, check out Google Earth and search for impact craters.

But, you’re also right that there are many fewer on the Earth than the Moon. This is because of the two points you mentioned: atmospheric destruction of the incoming meteorite, erosion, and sedimentation. Those last two, in particular are responsible for most of the cover-up work of larger impacts. Take, for example, the Chixculub crater, which many scientists believe to have been caused by the impact which led to the extinction of the dinosaurs. That crater impacted in a shallow sea, and is completely invisible at the surface due to sedimentation filling in the crater, and erosion of upturned beds surrounding the crater’s rim. Nevertheless, we can still tell it’s there by looking for geologic clues like glass beads and certain other minerals.

Another point to be made here is that the visible surface of the Earth hasn’t been that way for long. With the exception of stable continental interiors, like the Canadian Shield, most of the Earth’s surface is geologically young compared to the moon.

While it’s possible that the Moon migrated here from elsewhere in the solar system, there’s good enough evidence about the mineral composition of the Earth’s mantle and the Moon that we can infer their common origin.

]]> By: gerardo alvarez http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36572 gerardo alvarez Thu, 19 Nov 2009 20:39:14 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36572 I forgot final question on my previous mail minutes ago. Or perhaps could it be that the Moon had actually originated somewhere else in space,(nothing to do with Earth),with more activity of metheorites ,and/or it is much older than Earth,and thus so many more times hit by metheorites? Thank you I forgot final question on my previous mail minutes ago.

Or perhaps could it be that the Moon had actually originated somewhere else in space,(nothing to do with Earth),with more activity of metheorites ,and/or it is much older than Earth,and thus so many more times hit by metheorites?
Thank you

]]> By: gerardo alvarez http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36571 gerardo alvarez Thu, 19 Nov 2009 20:21:26 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36571 Hi Rather than a reply I have a question, and while it refers to the Moon,it is not about the subject here.So very sorry,but still perhaps somebody could answer. Question: If total surface of Earth is about 10 times larger than total surface of the Moon,and if Earth is older than Moon(actually it is said that Moon was made of material ejected from Earth), and if Moon is only 384,000 Kts away from Earth (so close neighbours by Astronomical distances),then why /how there are on the Moon about half a million craters larger than 1 Kt diameter,and only a few dozens on Earth?. I know that small meteorites are volatilized by the Earth atmosphere (while none in the Moon),and I know that there is erosion,and vegetation on Earth and not in the Moon,but even so,.....I am asking about large meteorites not volatilized and not posibly eroded ... are the corresponding millions of large craters hidden under the Earth surface? And how many( 3 times more?) at the bottom of the 3/4 of earth surface ,ie Oceans?. Thank you. Regards Gerardo Alvarez Hi
Rather than a reply I have a question, and while it refers to the Moon,it is not about the subject here.So very sorry,but still perhaps somebody could answer.
Question:
If total surface of Earth is about 10 times larger than total surface of the Moon,and if Earth is older than Moon(actually it is said that Moon was made of material ejected from Earth), and if Moon is only 384,000 Kts away from Earth (so close neighbours by Astronomical distances),then why /how there are on the Moon about half a million craters larger than 1 Kt diameter,and only a few dozens on Earth?.
I know that small meteorites are volatilized by the Earth atmosphere (while none in the Moon),and I know that there is erosion,and vegetation on Earth and not in the Moon,but even so,…..I am asking about large meteorites not volatilized and not posibly eroded …
are the corresponding millions of large craters hidden under the Earth surface?
And how many( 3 times more?) at the bottom of the 3/4 of earth surface ,ie Oceans?.
Thank you. Regards Gerardo Alvarez

]]> By: robert http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36535 robert Sat, 01 Aug 2009 21:06:20 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36535 since my father helped build the first laser they used. I found your article very pleasing to read thank you for posting it since my father helped build the first laser they used. I found your article very pleasing to read

thank you for posting it

]]> By: c gray http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36443 c gray Tue, 12 May 2009 12:42:11 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36443 I've just discovered through a weather website that light slows down by 0.03% when entering the atmosphere.Does it therefore follow that it will accelerate on leaving,i guess so and i suppose the moon distance measurement is weighted to include this. I’ve just discovered through a weather website that light slows down by 0.03% when entering the atmosphere.Does it therefore follow that it will accelerate on leaving,i guess so and i suppose the moon distance measurement is weighted to include this.

]]> By: c gray http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36424 c gray Thu, 07 May 2009 14:38:17 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-36424 Could we use this technique to gather information about mars with the next unmanned visit? Or is just too far away. Could we use this technique to gather information about mars with the next unmanned visit? Or is just too far away.

]]> By: Joe Vann http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-35895 Joe Vann Sat, 22 Nov 2008 20:31:05 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-35895 You state that the laser beam which started at 1m in width on earth had diverged to 10 km on the moon due to the atmosphere. I wonder if any of the spread can be attributed to the model of the propagation, usually a gaussian pulse, in calculating the spread. Such a pulse does not satsify Maxwell's equations exactly and is an approximate solution. Could any of the spread be due to errors accumulated in the model? You state that the laser beam which started at 1m in width on earth had diverged to 10 km on the moon due to the atmosphere. I wonder if any of the spread can be attributed to the model of the propagation, usually a gaussian pulse, in calculating the spread. Such a pulse does not satsify Maxwell’s equations exactly and is an approximate solution. Could any of the spread be due to errors accumulated in the model?

]]> By: ash http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-11435 ash Fri, 09 Mar 2007 12:42:27 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-11435 very very informative...helpd me with my physics assignment on LLR!!!thnx! very very informative…helpd me with my physics assignment on LLR!!!thnx!

]]> By: Jaime Acevedo http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-5964 Jaime Acevedo Tue, 12 Dec 2006 20:35:45 +0000 http://www.anthonares.net/2006/03/bouncing-laser-beams-off-of-the-moon.html#comment-5964 Congratulations! This definitively shut down any question about fake Apollo landings on the Moon. Congratulations! This definitively shut down any question about fake Apollo landings on the Moon.

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