Why isnt the moon obscured by atmospheric particles?

originally posted by: clevargenuis

originally posted by: hellobruce

originally posted by: clevargenuis
If you were to look at a distant mountain it appears hazy and blurred and you cannot see any features on it.

This is caused by suspended atmospheric particles, vapor, smog etc.

Yet the moon which is much further from our eye than mountains appears so crystal clear you could almost count the craters on it.

So why is this?

Have a look at high high the atmosphere goes, and how much dust/moisture is in it, compared to how much dust/moisture is close to the ground.

between your eye and the moon there is a lot of dust and moisture

that depends on your vantage point

a reply to: clevargenuis
You've really never seen the moon hidden behind clouds, or made dim behind clouds? What else do you think clouds are?
Similarly thick local fog is enough to obscure the moon (and even the sun).
The reflected light is enough to cut through lesser varieties of pollution.

originally posted by: DISRAELI
a reply to: clevargenuis
You've really never seen the moon hidden behind clouds, or made dim behind clouds? What else do you think clouds are?
Similarly thick local fog is enough to obscure the moon (and even the sun).
The reflected light is enough to cut through lesser varieties of pollution.

im not talking about clouds. even on a cloudless night the moon appears crystal clear like as if there were no atmospheric particles

What Markovian said.

Ten (or so) km of atmosphere between sea level and space and it thins out the higher you go.

If you're looking at a mountain in the distance, it's probably further than ten km (which is not very far) and the atmosphere is densest.

a reply to: clevargenuis

Here a moonrise time lapse: vimeo.com...

Seems to be clearly affected by the atmosphere to me.

What makes the moon stand out is that it is often the brightest object when observed. So you'll see more details.

Google for "daytime moon" and you will see plenty of images with highly varying visibility of the moon surface, thanks to lighting and atmospheric conditions.

What image is that mountain range.. Because I'm suspecting it is the blue mountains in Australia, in which the air is filled with oil droplets from the eucalyptus trees causing a blue haze..

Compare a picture with the alps or himalayas on a clear day and you can see the details for miles..

a reply to: clevargenuis

When you look around the curve of the Earth, the atmosphere keeps going on for hundreds/thousands of miles. When you look up the atmosphere thins out until at 90 miles; is entirely gone.

Also there is difference between light going through the atmosphere and light reflecting off the atmosphere. For instance, you can see stars at night but, during the day, the bright light of the Sun is so brightly reflected that we can no longer see the stars.

a reply to: clevargenuis

I get what your saying about looking through the atmosphere but I would have thought the reason the moon looks so clear is because it`s illuminated by the sun when we see it. At least that`s what I`ve always thought.

a reply to: clevargenuis

Your answer is very simple and it's boil down to this question:

Do you see difference when viewing the moon rising just over the horizon and then later high in the sky?

Also, there is a difference between daylight and night, during daylight you have to deal with Rayleigh and Mie scatter from Sun light onto mist, water vapor and atmosphere.

ETA:

Here a nice link on the "angularity" of scatter:

Rayleigh and Mie Scattering

a reply to: clevargenuis

Easy. Close to ground with rising particles dust clouds etc...like mountains....and extremely high SUSPENDED objects brightly lit.

Ie: steam or fog at ground level....and looking up toward sun.

a reply to: clevargenuis

It's a fair question, the best I can explain is that the atmosphere is a little like an onion skin, it has different layers, now it is also like an ocean but one made of Gases.
www.nasa.gov...
education.nationalgeographic.org...

Think how a barometer measures differences in air pressure (The weight or pressure of the atmosphere on the mercury or alcohol in it's bulb squeezes it and pushes the fluid up the thin capillary tube which is marked with gradient's for measuring that pressure) is measures or rather react's to how how much the weight's of the air over it changes and most barometers are calibrated to sea level but of course they are highly inaccurate compared to modern measuring instrument's.
blogs.britannica.com...
van.physics.illinois.edu...

Down here on the surface we are at the bottom of that ocean or on the inner layer of that onion skin.

When you look through it at the horizon you are actually lookint through the thickest part's of the atmosphere, the densest/thickest part and also the layer were most dust/pollen and most pollution gas is suspended in the air.

All air refracts light though which is why the sky has a colour and the sun light's up the whole sky during the daytime.

Now when you look up you are actually looking through progressively thinner layers of the air, just like a mountain climber struggles to breath higher up there is less air to distort the view of space the higher you go, so it is less distorting than looking toward the horizon were the air is at it's thickest and you are merely trying to see through the most opaque part of the atmosphere (gas the ocean is actually the thickest part but we of course do not live in the ocean/sea).

And it actually does still distort the moon but the moon is so large and so bright with reflected sunlight that it still shine's through the air just like a powerful headlight on a car can shine through thick fog.

Stars are also extremely bright which is why they are still visible but the atmosphere often make's then twinkle, that is not the stars but atmospheric distortion which ripples the light from them and we see it as a twinkle.

Now maybe someone else can give a better answer.

Haze, humidity, and dust are more prevalent close to the ground. Therefore, when you look toward the horizon, you are looking through much much more of the haze, humidity, and dust than you would be looking through if you looked straight up.

That's why the Moon can sometimes (depending on conditions) look a little orange when it is rising or setting, but NOT look orange on that same day while it is high in the sky. It looks orange for the same reason a sunset or sunrise looks redder and oranger than the Sun does when it is high in the sky.

Furthermore, on foggy days, the Moon is much more obscured by the fog when trying to view the moon low on the horizon than when viewing the Moon higher in the sky -- and that's because you are looking through much more fog when viewing the Moon near the horizon.

That atmosphere thins out relatively quickly as it goes up. At 25,000 feet (5 miles) up, there is barely enough oxygen to breath; looking through 5 miles of thick air while looking at a distant mountain range on the horizon is quite different.



By the way, we can also see Jupiter (which is MUCH further away than the Moon) relatively clearly through our atmosphere:

originally posted by: clevargenuis
If you were to look at a distant mountain it appears hazy and blurred and you cannot see any features on it.


Yet the moon which is much further from our eye than mountains appears so crystal clear you could almost count the craters on it.

So why is this?

Look at it a different way, If you couldn't see the Moon, you would not see the stars either.

I think the guys have explained it pretty well, Nightime you could also say leaves the atmosphere less dense than daytime, even more so in the ionosphere, the ionosphere is much less charged at night time.

It's the size difference.
If you stand at one end of a basketball court with a golf ball and a basketball ,you wouldn't be able read the golf ball but you would be able to read the basketball.

I think smurfy is spot there! And starting from the beginning you should have your question answered.

The higher up you get before starting observation of the stars in a observatory the less atmospheric distortion you have to deal with (looking through all those layers s labtech pointed out).

You know how they deal with that? Lasers. Yep, those quantum mechanic devices are shone (shined? Not enough coffee yet ) up through the layers and observed through a smaller telescope. Computers then compensate the received light (complicated math and stuff) to clean up the resulting pictures. Pretty clever little monkeys if you ask me!

originally posted by: clevargenuis
If you were to look at a distant mountain it appears hazy and blurred and you cannot see any features on it.

This is caused by suspended atmospheric particles, vapor, smog etc.

Yet the moon which is much further from our eye than mountains appears so crystal clear you could almost count the craters on it.

So why is this?

When you're looking at the mountain range, you are looking horizontally and through the Troposphere, the most dense part of Earths atmosphere. When viewing the Moon, you are looking vertically through the layers of the atmosphere and depending on the latitude you are viewing from, the Troposphere is anywhere from 12 m thick at equatorial latitudes to as little as 4.3 miles at the poles.

The troposphere contains around 3/4 of the mass of the entire atmosphere and roughly 99% of all the water vapor as well as being the layer in which all weather takes place. Time of year will also affect visibility, thinner troposphere in winter months, thicker in summer months. This is why when you look up at the stars everything is much clearer in the winter and hazier in the summer.

To put it more simply, when you look up, you're looking through less smog, water vapor and other assorted detritus compared to looking across through all of the atmospheric detritus.

originally posted by: Phage
Because the Moon is one of them hollowgrams.

lol....phage....I'm sure you had many other responses, but the pain from biting your tongue worked well in this case.

whats up with the sun ?

A time lapse I did of clouds and the moon.

I work on radar that "sees" a long way. We deal with this issue on low elevation looks. There is a lot of attenuation. Think of it this way. Say you are sitting on a flat plane that is 10 miles by 10 miles square and for the first mile up 90% of the dust and haze is suspended. Above this is very clear. Just hypothetical numbers.

If you look straight up, you are looking through 1 mile of haze. If you look off to the right 10 miles, you are looking through 10 miles of haze, so it will be 10x murkier. Any angle other than straight up, and you are looking through some longer distance. It is all just geometry looking through concentric spheres (layers) of atmosphere.

If it is a clear day and you can see to the right 10 miles clear, it will be 10x clearer looking straight up. If you are on a mountain a mile up, you are already above the murky part and it will be a many times clearer view of space. A good test is to go out on a hazy evening and wait until the stars come out. Look at the stars on the horizon vs the ones straight up.