Footprints on the Moon

05/29/203 | patriotUSA

[InvisibleChurch]

i remember a Night Gallery show about astronauts running into a giant mousetrap on the moon ... THAT is probably visible...

GO Homeschoolers!!!

[Dead Corpse]

No. From the Hubble website:
1. Size: An object on the moon 4 meters across, viewed from HST, would be about 0.002 arcsec in size. The highest resolution instrument currently on HST is the FOC, at 0.014 arcsec. That would work out to being able to resolve something about 300 ft across on the moon. So anything we left on the moon cannot be resolved in any HST image. It would just appear as a dot -- except see next point.
2. Motion of the moon: The HST pointing system is designed to hold it quite motionless relative to the distant stars -- but the Moon isn't. In 1 second of time, the moon moves over 0.5 arcsec. The shortest exposure time any of the HST instruments offers is 0.1 sec -- so an object we left on the Moon would appear more blurry.

Best orbital cameras and spy-sats can image the headline off a newspaper pointing down at the Earth, but good luck getting the NSA to point one towards the moon.

[TXBubba]

My first thought was that they wouldn't still be there even if there was the ability to see them.

[mass55th]

Looks like one of the snow piles here this past winter.

[AppyPappy]

It still wouldn't be able to see footprints from that far away

[Redbob]

Maybe this question has to do with which SIDE of the moon the landing took place, rather than the optical resolution of telescopes?

(Hint: If it was the backside of the moon, which NEVER faces Earth...)

[Consort]

[RightWhale]

Is there any telescope available that can discern the footprints left on the moon?

No. One of the giant professional or university telescopes might do it from 1,000 miles, but the moon is 240 times farther. If the footprint were 240 feet across it would be one pixel wide, so, maybe.

[GreenHornet]

Maybe on Mars.

Have you been talking to Sheila Jackson Lee?

[SquirrelKing]

[judgeandjury]

No, because we've never been there, nor will we ever be able to go there.

"There is no hope for the fanciful idea of reaching the moon, because of insurmountable barriers to escaping the earth's gravity."
-University of Chicago astronomer Dr F. R. Moulton, 1932

[Redcloak]

All you need is a telescope with an 3117 km aperture.

[smadurski]

we all know that we never really landed on the moon. It was all done in a hollywood studio. If you really believe this just ask Buzz Aldrin (sp?).

[RightWhale]

All the Apollo landings and most of the robot landings were on the side of the moon facing earth. Some were near the limb, the edge of the full moon, but still within sight of earth.

[muir_redwoods]

No. Assuming the footprint is 12 inches long and you could discern it normally from say, 100 feet and the moon is 250,000 miles away you would need a magnification of something like 100 million power. This in turn (according to Dawes Limit) would require an aperture of a million inches or 16 miles.

I think ;-)

[TheCause]

Dear dead dude:

Break out the Reynolds Wrap!

[snarkpup]

I have heard that the Hubble would be blinded immediately if it looked at something as bright as the earth or the moon. It has mechanisms that automatically close the cover if it gets within a certain number of degrees of either one.

[Lonesome in Massachussets]

>> All you need is a telescope with an 3117 km aperture.

Say the footprints were 30 cm (12 inches) across, the mean distance to moon is 384,000,000 meters. The angle subtended would be 0.3/(384,000,000) radians = 7.8125/10000000000 radians = 4.47623/10000000 degrees = 0.000161144 arcseconds. The resolving power of a telescope in radians is equal to the diameter over the wavelength. Figure light ~ 600/10000000000 meters wavelength, so you'd need an aperture or about (600/10000000000) meters/(7.8125/10000000000) ~ 468 meters, to make even a very blurry image.

Of course you don't need a fully filled aperture to achieve that resolving power, you could have gaps. But then your light gathering would be very low, and the sidelobe levels would be so high that you probably couldn't see anything anyway.

Oh, and the atmosphere is not stable over that kind of distance, so even if you had perfect optics, the image would be blurred by atmospheric irregularities. (You might consider adaptive optics, but you could probably fly to the Moon for less.)

[edwin hubble]

"True, however you can bounce lasers off mirrors and some of the other equipment they left behind which we do to measure precise distances between the earth and the moon. "

These are examples of evidence of the Apollo missions to the moon.

Retro-reflectors placed by three Apollo missions are used almost every clear night (this week, for instance) by observatories in Texas and France to measure the distance and motion of the moon to great accuracy (to centimeter resolution). This data has confirmed Earths's continental drift, the moon's motion away from the Earth, and information about the moon's interior.

Seismographs placed by Apollo missions gave readings from the moon (by radio) and tracked meteorite impacts through the 1970's. These were calibrated by dropping things onto the lunar surface.

Large telescopes on Earth also recorded images of the Apollo missions return launches and rocket firings from the moon. These photographs show the Apollo rockets firing from near the lunar surface.

We also have 842 pounds of lunar rocks which any competent geologist can verify are not from Earth, but from the moon.

[Dead Corpse]

Really?

What's this?