Observing from the Moon?

[Mezolitik]

Hi all,

A bit of a hypothetical question - If you could take your telescope to the Moon and observe the stars, would you be able to pick out the same objects and constellations as you can from the Earth? I would imagine that the seeing is better, given the lack of a substantial atmosphere, but would there be any other major differences?

Also, would the presence of the Earth in the sky cause major issues for Moon 'scopes?

Thanks!

[andrew65]

Sure i read somewhere you cant see stars from the moon because its so bright you'd have to be on a part not in sunlight.you'd have to go to the darkside :-)

[Naemeth]

Sure i read somewhere you cant see stars from the moon because its so bright you'd have to be on a part not in sunlight.you'd have to go to the darkside :-)

Sorry, I'll have to correct you here, there is no dark side of the Moon, only Far Side of the Moon, which receives on average exactly the same amount of sunlight as the Near Side. The trick would be to go to the bottom of a very deep crater that is permanently shaded, and observe there all day, every day.

[steveb1977]

Without the atmosphere seeing would be perfect with the moon and earth out of the sky, i think either would wash out the stars if they were above the horizon. The constellations would all look the same as well. Nights would last a couple of weeks as well!

[andrew65]

So pink floyds album should have been called far side of the moon you learn something everyday on here :-)

[Zakalwe]

Yep, no fixed "dark side"......its amazing how often that meme pops up! No atmosphere, so no "seeing" to affect things. No need for dew bands either! Week long nights, no light pollution, and no clouds!!! And the far side would be perfect for radio astronomy too.

Of course you get zapped with high levels of ultraviolet and a solar flare would mess your day up. And you'd need a new mount to track the sky. Dropping a screw would be a pain as space suit gloves are very very stiff. One of the biggest problems, surprisingly, would be the Lunar regolith. Some people think that the dust would present one of the biggest challenges to long term Lunar living....it's incredibly abrasive (no erosion) and it gets everywhere (static charges build up very easily as there is no atmosphere to leak a charge away, plus everything is exposed to charged particles from the solar wind) . The Apolo astronauts had to take extreme care as the dust was sticking in the glove and helmet cuffs.

[lukebl]

I suppose when the phrase 'dark side of the moon' was originally coined they were using the word 'dark' to mean 'unknown' or 'unexplored' as in 'darkest Africa.' The word has stuck and the general public now take it literally!

[DazC]

Sure i read somewhere you cant see stars from the moon because its so bright you'd have to be on a part not in sunlight.you'd have to go to the darkside :-)

Darkside?

What imaging?!!

D.C

[DeepThought]

The sun might well spoil the naked eye view on the light side but I presume with no atmosphere to diffuse the sunlight you would still able to see objects through a telescope as if it were night as long as your tube was flocked.

I also presume the "earthshine" would play a part.

Getting dark adjusted would be a challenge though.

[Bluey]

It would be great to look back at Earth and see the clouds from the other side for a change

[Doshy]

So pink floyds album should have been called far side of the moon you learn something everyday on here :-)

"There is no dark side of the moon. As a matter of fact, it's all dark"

[skiorh]

I agree with Naemeth that a deep crater would do. Theoretically you could be observing with the Sun and Earth up as there is no atmosphere to scatter the light (like Zakalwe says) but problem is the seeing of faint objects - same rules as on Earth would apply, you'd get blinded by the sun + earth + reflection of the Moon's surface. So perhaps a really really deep hole with narrow FOV would be fine during the Moon day, haha.

What would be quite cool though is the slow rotation of the Moon which means a really easy object tracking - a paradise for imagers

[Zakalwe]

The sun might well spoil the naked eye view on the light side but I presume with no atmosphere to diffuse the sunlight you would still able to see objects through a telescope as if it were night as long as your tube was flocked.

I also presume the "earthshine" would play a part.

Getting dark adjusted would be a challenge though.

It'd be no different to observing on Earth. After all, we rarely observe during the day! The Moon's night is nearly a month long, so you'd have no problem getting dark adapted. Mind you, you'd have the same time to wait for night-fall once daytime came.

The Apollo astronauts could see stars during the day if they looked through the LM optics (the AOT, Alignment Optical Telescope)...indeed doing so was a requirement to get an orientation on the Lunar surface. http://apollo.spaceborn.dk/aot.html

[freeflyjay]

of course it would be better, your closer after all......lol....in all seriousness at lunar night on the far side of the moon to block earth i would imagine that seeing would be better with the lack of atmosphere.

[Zakalwe]

of course it would be better, your closer after all......lol....in all seriousness at lunar night on the far side of the moon to block earth i would imagine that seeing would be better with the lack of atmosphere.

Absolutely.

Since seeing is an atmospheric artefact caused by light being refracted in pockets of air, then no atmosphere = no seeing.

[lukebl]

....The Moon's night is nearly a month long,.....

Not quite right. True, the moon's entire 'day' is nearly a month long, so the night is about two weeks long. Sorry. being pedantic!

[Zakalwe]

Not quite right. True, the moon's entire 'day' is nearly a month long, so the night is about two weeks long. Sorry. being pedantic!

Opps...you are, of course, correct (and not pedantic).

I stand corrected.

[Stu]

So..... Full moon on earth should be best time to observe, assuming you were on the far side of the moon. Sun would be completely blocked and no earthshine to bother you.

Guess it might be a little chilly though, perhaps long johns would be needed, or am I forgetting something???

Actually, might need some very long eye relief ep,s to allow you to observe whilst wearing a space suit and helmet!!!

Stu

[matthewota]

You would have to observe during the lunar nighttime on the far side of the moon. THe astronauts reported that the Earth was four times brighter than the full moon in the lunar sky when they were there.

In addition you would need a new clock drive as the luanr day is 29 d 12 h 44 min 2.9 s not 24 hours as it is on the earth.

You would also need to adjust the eyepiece optics as you would need a lot more eye relief as you wold be viewing through a faceplate.

the telescope gears would have to be lubricated with vacuum reated grease.

Finally, the telescope would have to be insulated with aluminized Kapton (mylar) to keep teh temperatures stable.

Joun Yound set up an Ultraviolet telescope on the moon in April, 1972 during Apollo 16.

[lukebl]

Of course, if you were viewing from the far side, the glow from the earth wouldn't be a problem as the earth never rises on that side!

[Zakalwe]

Finally, the telescope would have to be insulated with aluminized Kapton (mylar) to keep teh temperatures stable.

Not at all. It'd soon radiate it's heat away (to the sky) and drop to near absolute zero. It'd be interesting to see how the materials, mirror, coatings and so on would cope at that temperature.....

The cooling on CCDs wouldn't work. You'd need to replace the peltier and heatsink with something like the sublimaters in the PLSS. Which would then need a watersource, piping and so on.

[matthewota]

That is correct. the only way to see "earthrise" is to be in orbit around the moon, ala the Apollo CSM. Oddly. if you stayed for a month on the Moon, you would see the earth fixed in one place in the sky, and it would go through phases as the sun slowly travels across the sky.

[Stu]

Just doing some reading on this.... It doesn't seem totally clear whether the earth will also become tidally locked to the moon eventually, or whether the moon will drift far enough away before then and we become locked to the sun which won't be good news. Several billion years in the future though I guess so no need to worry just now!!!

Stu

[freeflyjay]

Just doing some reading on this.... It doesn't seem totally clear whether the earth will also become tidally locked to the moon eventually, or whether the moon will drift far enough away before then and we become locked to the sun which won't be good news. Several billion years in the future though I guess so no need to worry just now!!!

Stu

the earth is slowing, but i remember reading that the sun will die long before we became tidally locked to the moon, so i wouldn`t worry

[Scosmico]

If I was on the moon I would do a lot of Earthgazing.