Stars & the Solstice Sun

[Palomar]

http://antwrp.gsfc.nasa.gov/apod/ap070621.html

What an interesting composite image. :)

If you could turn off the atmosphere's ability to scatter overwhelming sunlight, today's daytime sky might look something like this ...

Accurate for the exact time of today's Solstice, this composite image also shows the Sun at the proper scale...Digitally superimposed on a nighttime image of the stars, the Sun itself is a composite of a picture taken through a solar filter and a series of images of the solar corona recorded during the solar eclipse of February 26, 1998 by Andreas Gada.

:cool:

[Tucson_Tim]

Very interesting!

You can do this yourself my plotting the Sun's position on a good star chart - just not as pretty.

[Qbert]

Okay, so what's up with the following NASA statements:

From above:
If you could turn off the atmosphere's ability to scatter overwhelming sunlight, today's daytime sky might look something like this ... with the Sun surrounded by the stars of the constellations Taurus and Gemini

From here: http://www.hq.nasa.gov/alsj/a13/images13.html
stars are not readily seen in the daylight lunar sky by either the human eye or a camera because of the brightness of the sunlight surface

And from here: http://liftoff.msfc.nasa.gov/academy/universe/moon.html
In fact, the moon is about the poorest reflector in the solar system. The amount of light reflected by a celestial object is called the albedo (Latin: albus, white). The moon relects only 7% of the sunlight that falls upon it, so the albedo is 0.07

If the Earth's albedo is 0.367 why such a difference? Or is one of these statements just wrong?

[NEOWatcher]

Okay, so what's up with the following NASA statements:
Could you please ask a question that is a little less broad?


If the Earth's albedo is 0.367 why such a difference? Or is one of these statements just wrong?
You might be confusing scattering and reflectivity. Two different things.

[Qbert]

Sorry, I thought there was a clear contradiction in the quotes, but I'll rephrase my question. Here's what I'm getting out of the above statements:

1) From the Earth's surface, if it had no atmosphere, you could see the sun and the stars at the same time.

2) From the moon's surface, with no atmosphere, stars are not readily seen because of the brightness of the surface.

3) The moon's surface is a much poorer reflector of light than the earth's surface.

I'm asking why they are saying you would see stars on the Earth but not on the moon. What difference between the two explains this?

[NEOWatcher]

Sorry, I thought there was a clear contradiction in the quotes, but I'll rephrase my question. Here's what I'm getting out of the above statements:

1) From the Earth's surface, if it had no atmosphere, you could see the sun and the stars at the same time.

2) From the moon's surface, with no atmosphere, stars are not readily seen because of the brightness of the surface.

3) The moon's surface is a much poorer reflector of light than the earth's surface.

I'm asking why they are saying you would see stars on the Earth but not on the moon. What difference between the two explains this?
The moon references are for photography and not for naked eye viewing.

It is an explaination as to why stars aren't visible in Apollo photographs. I'm sure Earth photographs would have the same problem without an atmosphere.
It's a matter of contrast.

Apples (or applications) and oranges.

[Qbert]

Or in other words, you're saying that NASA simply needs to correct the erroneous information on their website (i.e. the second quote from my original post)?

[NEOWatcher]

Or in other words, you're saying that NASA simply needs to correct the erroneous information on their website (i.e. the second quote from my original post)?
I didn't notice they said human eye, but I still think it's apples and oranges.
APOD is probably making a simple statement about something that isn't real anyway, so they don't go into detail on what they are saying.

The moon statement might also consider that the human eye is not that efficient with high light situations also.

So yeah...somebody needs some clarification, I can see where the conflict is.

[hhEb09'1]

So yeah...somebody needs some clarification, I can see where the conflict is.Also, in that area shown, there is only about a dozen or less naked-eye visible stars! I wish we could see that view at night! :)

[Dave Mitsky]

The Apollo astronauts could certainly have photographed stars quite well from the lunar surface if they had used long enough exposures with tripod-mounted cameras. From what I've read on the subject, a few of the lunar photographs do indeed show some stars.

Dave Mitsky