APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 5401
Joined: Fri Dec 04, 2009 3:27 am

APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by APOD Robot » Sat Jul 29, 2023 4:06 am

Image Apollo 11: Catching Some Sun

Explanation: Bright sunlight glints as long dark shadows mark this image of the surface of the Moon. It was taken fifty-four years ago, July 20, 1969, by Apollo 11 astronaut Neil Armstrong, the first to walk on the lunar surface. Pictured is the mission's lunar module, the Eagle, and spacesuited lunar module pilot Buzz Aldrin. Aldrin is unfurling a long sheet of foil also known as the Solar Wind Composition Experiment. Exposed facing the Sun, the foil trapped particles streaming outward in the solar wind, catching a sample of material from the Sun itself. Along with moon rocks and lunar soil samples, the solar wind collector was returned for analysis in earthbound laboratories.

<< Previous APOD This Day in APOD Next APOD >>

User avatar
Rauf
Science Officer
Posts: 217
Joined: Tue Oct 09, 2018 3:47 pm

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Rauf » Sat Jul 29, 2023 6:13 am

I read somewhere that using those crosses on the picture, you can determine angular distance or sth? but how?

madtom1999
Ensign
Posts: 85
Joined: Mon Jan 12, 2009 11:21 am

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by madtom1999 » Sat Jul 29, 2023 10:07 am

As a kid I my dad came home with some prints direct from the negatives from the moon and they were just amazing. He also had a glass phial with some supposedly moon rock in. He was a man of extreme views and I did wonder if he was just trying to encourage me into science and these things were just baubles to do so. Then the fiftieth anniversary of the landings had our near neighbour Prof Lionel Wilson on national radio, Sometimes you can actually hold a piece of the moon in your hand!

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by orin stepanek » Sat Jul 29, 2023 12:26 pm

AS11-40-5872HR1024.jpg
I remember my wife and I went to a sci-fi movie when they reported
landing on the moon! That was a big moment back in those days! I
could never understand why we quit pursuing lunar exploration after
that! :roll:
82868958_3413326812070702_8997963657715384320_n.jpg
Going for a ride on the moon :D
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

User avatar
Chris Peterson
Abominable Snowman
Posts: 18267
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Chris Peterson » Sat Jul 29, 2023 1:22 pm

orin stepanek wrote: Sat Jul 29, 2023 12:26 pm I remember my wife and I went to a sci-fi movie when they reported
landing on the moon! That was a big moment back in those days! I
could never understand why we quit pursuing lunar exploration after
that!
We didn't. But we quite correctly recognized that there's nothing we can do on the Moon that can't be done better by a robot than a man. A lesson that we are unfortunately ignoring now.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
Chris Peterson
Abominable Snowman
Posts: 18267
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Chris Peterson » Sat Jul 29, 2023 1:27 pm

Rauf wrote: Sat Jul 29, 2023 6:13 am I read somewhere that using those crosses on the picture, you can determine angular distance or sth? but how?
Not exactly. What they do is provide a dimensional reference on the film, which gets mechanically distorted during processing and handling. So they provide a correction mechanism for calculating accurate angular measurements, but not absolute distance.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

Brewz

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Brewz » Sat Jul 29, 2023 2:12 pm

Generally not a conspiracy theorist, but I believe the USA flag has been added by external means.

User avatar
Chris Peterson
Abominable Snowman
Posts: 18267
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Chris Peterson » Sat Jul 29, 2023 2:21 pm

Brewz wrote: Sat Jul 29, 2023 2:12 pm Generally not a conspiracy theorist, but I believe the USA flag has been added by external means.
In other words, you're a conspiracy theorist!
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

Guest

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Guest » Sat Jul 29, 2023 7:49 pm

It looks like there are two suns. I assume this is a photographic reflection of some sort. Or does the moon really have two suns?

User avatar
Chris Peterson
Abominable Snowman
Posts: 18267
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Chris Peterson » Sat Jul 29, 2023 8:04 pm

Guest wrote: Sat Jul 29, 2023 7:49 pm It looks like there are two suns. I assume this is a photographic reflection of some sort. Or does the moon really have two suns?
Of course, the Sun isn't actually in this image at all, just lens flares from it.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
johnnydeep
Commodore
Posts: 2926
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by johnnydeep » Sat Jul 29, 2023 8:57 pm

Chris Peterson wrote: Sat Jul 29, 2023 1:27 pm
Rauf wrote: Sat Jul 29, 2023 6:13 am I read somewhere that using those crosses on the picture, you can determine angular distance or sth? but how?
Not exactly. What they do is provide a dimensional reference on the film, which gets mechanically distorted during processing and handling. So they provide a correction mechanism for calculating accurate angular measurements, but not absolute distance.
So the crosshairs are at the corners of squares (when the image was originally taken), and that's what enables any distortions to be corrected?
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

User avatar
Chris Peterson
Abominable Snowman
Posts: 18267
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by Chris Peterson » Sat Jul 29, 2023 9:35 pm

johnnydeep wrote: Sat Jul 29, 2023 8:57 pm
Chris Peterson wrote: Sat Jul 29, 2023 1:27 pm
Rauf wrote: Sat Jul 29, 2023 6:13 am I read somewhere that using those crosses on the picture, you can determine angular distance or sth? but how?
Not exactly. What they do is provide a dimensional reference on the film, which gets mechanically distorted during processing and handling. So they provide a correction mechanism for calculating accurate angular measurements, but not absolute distance.
So the crosshairs are at the corners of squares (when the image was originally taken), and that's what enables any distortions to be corrected?
Maybe. The point is, they are at very precisely known positions (on a glass plate inside the camera, that the film is pushed up against). That they lie on a precise grid would make sense, but they don't need to.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
johnnydeep
Commodore
Posts: 2926
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Apollo 11: Catching Some Sun (2023 Jul 29)

Post by johnnydeep » Sun Jul 30, 2023 12:56 pm

Chris Peterson wrote: Sat Jul 29, 2023 9:35 pm
johnnydeep wrote: Sat Jul 29, 2023 8:57 pm
Chris Peterson wrote: Sat Jul 29, 2023 1:27 pm

Not exactly. What they do is provide a dimensional reference on the film, which gets mechanically distorted during processing and handling. So they provide a correction mechanism for calculating accurate angular measurements, but not absolute distance.
So the crosshairs are at the corners of squares (when the image was originally taken), and that's what enables any distortions to be corrected?
Maybe. The point is, they are at very precisely known positions (on a glass plate inside the camera, that the film is pushed up against). That they lie on a precise grid would make sense, but they don't need to.
Ah, got it.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}