Free Republic
Browse · Search
General/Chat
Topics · Post Article

To: dr_lew
Once I went back and re-read that paragraph in the article several times - and naturally after I posted my comment to you [grin]- I finally got what the scribbler was probably trying to get across. [Professionalism (or at least English literacy) in 'journalism' just seems not to exist any more.]

I guess that "These are to our knowledge, these super-cold brightness temperatures (sic) are among the lowest that have been measured anywhere in the solar system, including the surface of Pluto" as written on the NASA page, when run through the 'semi-literate journalism' filter becomes "This means the shadowed floors within Cabeus and its neighbors are the most frigid places known in the entire solar system (emphasis in original). To my mind, there is a pretty vast difference between the two statements-- and just seems to indicate the writer's incompetence, or at least his desire for sensationalism.

But, anyway...

Another thing that struck me when I was trying to visualize the earth/moon/sun spatial relationship was this: Although we only see one side of the moon because it is tidal locked to our planet, doesn't the 'dark side' face the sun during its rotation around the planet as the planet rotates around the sun? So isn't the 'dark side' of the moon just 'dark' to us- or rather 'unseen' by us, while being illuminated by the sun when it is between earth and the sun?

I guess I will have to go find a good online representation of an orrery, as my spatial visualization seems to be severly lacking in that respect.

Then, after straining what few brain cells I do have left on that, another question arose: Why, when the moon is only 1 AU from the sun are places on it colder than places that are multiple or many AU's away from the sun. Doesn't the radiation fall off with the square of the distance, like light, thus subjecting distant objects to even less warming than what could be gotten closer to the solar furnace, i.e., the moon? I guess it's been too many years since those old college science courses.

Anyway, thanks for that picture. It is amazing. Am I correct in assuming that it was one of the ones taken during the suicide plunge of the LCROSS, since it seems so high rez and detailed?

16 posted on 11/10/2009 12:11:09 PM PST by hadit2here ("Most men would rather die than think. Many do." - Bertrand Russell)
[ Post Reply | Private Reply | To 15 | View Replies ]


To: hadit2here
So isn't the 'dark side' of the moon just 'dark' to us- or rather 'unseen' by us, while being illuminated by the sun when it is between earth and the sun?

Yes, but we are talking about the lunar poles, not the "dark side". Interestingly, the lunar axis of rotation is inclined by only 1.54 degrees to the plane of the earth's ( or earth-moon ) orbit around the sun, although it is inclined at 6.69 degrees to its orbit around the earth. The latter inclination gives it a "nodding" appearance from the earth, but the smaller inclination to its ( shared ) orbit around the sun means that the sun is never more than 1.54 degrees above or below the horizon at the poles, and the local topography at the south pole creates these deep shadow zones.

BTW, I was just experimenting with my STARRY NIGHT software, which lets me hover over the lunar south pole and watch the sky turn ( set to X30000 ) as the earth spins in front of me. Great stuff.

Why, when the moon is only 1 AU from the sun are places on it colder than places that are multiple or many AU's away from the sun.

We've been trying to tell you! But I think you're coming around. The moon's solidity and lack of atmosphere provides a shield against the solar radiation, and allows the deep cooling due to constant darkness without thermal contact to any gases. You might think that the rock itself would warm the place up through conduction, but the great thickness of it prevents this. You have to do the math, really, and in fact I don't think the experts were expecting anything very much below 100K

Am I correct in assuming that it was one of the ones taken during the suicide plunge of the LCROSS, since it seems so high rez and detailed?

That is NOT correct, sir! The image is from the Diviner Lunar Radiometer Experiment aboard the Lunar Reconnaissance Orbiter, launched last June.

17 posted on 11/10/2009 5:41:53 PM PST by dr_lew
[ Post Reply | Private Reply | To 16 | View Replies ]

Free Republic
Browse · Search
General/Chat
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson