View Full Version : Stupid Apollo Question
06-08-2000, 05:50 AM
I'm not that old, I was fairly young when the Apollo missions took place.
I was watching the sunset the other night; there was a beautiful glow to the sky, the moon was out, and there was a jet slowly crossing the sky. The jet, because it was high in elevation, was brightly lit by the sun and really stood out in contrast to the darker sky.
That's when it hit me; when the Apollo missions took place, could you see the sunlight reflecting off the spaceship as it headed for the moon? Did it look like a star that slowly got closer to the moon? Am I off my rocker?
You can see many satellites and spacecraft in low earth orbit. The Shuttle is as bright as the brightest star in the sky, and so is the Mir space station. These things, however, are only a few hundred kilometers away. I've never heard of anything higher up being visible to the naked eye. To see satellites in geostationary orbit, about 35,000 km (20,000 miles) away, you need to take a long exposure photo with a telephoto lens (and long exposure in astronomy means tens of minutes to many hours). The moon is 10 times farther than that. So the answer is, the Apollo would have been easily visible shortly after launch but would have faded away quickly.
06-08-2000, 07:49 AM
You may be interested in this (http://stephen.fathom.org/sathunt.html) link. The page is about satellite watching. My folks used to take my brother and me outside back in the seventies to watch satellites fly overhead. As I got older, I used to think that that was just a cute way of getting us to stand around looking up at the sky. But a few years back, I found out that they really were on the level with this one. Humph… now about the bear that lived in the 'presents' closet….
I found this page by following a link from another Doper, but don't remember who so I can't give credit. The page is on fathom.org, if that means anything.
06-08-2000, 08:54 AM
Remember, as the Apollo spacecrafts headed towards the moon, they dropped stages. By the time they left Earth orbit, they were down to the Command Module and the Lunar Module. Both objects would be almost impossible to see with the naked eye, and would be pretty difficult to spot even with a telescope.
06-08-2000, 01:53 PM
I can recall watching several satellites pass overhead from the UK back in the 70's - 80's. We would watch one go past, then another in a slightly different elevation. It was like there was always one visible at any time so we assumed maybe they were spy satellites, designed to have overlapping views. We assumed they were keeping an eye on the "Cold War" developments. I apologise for the serious answer.
06-08-2000, 02:04 PM
Remember, as the Apollo spacecrafts headed towards the moon, they dropped stages. By the time they left Earth orbit, they were down to the Command Module and the Lunar Module
Also, since they were headed away from earth, you'd be looking pretty much end-on, I suppose at the thruster nozzle on the back of the command module. Not a real highly-reflective surface.
06-08-2000, 04:53 PM
Am I the only one who was busy shining flashlights at the spacecraft, cackling, knowing that I could full well cause the downfall of the space program at any moment?
Yes, I had a lot of free time. To the best of my knowledge, nothing better was going on.
06-08-2000, 10:37 PM
Were there any type of lights on the CM or Lander?
Running lights, docking lights, that kind of thing.
I'm rather sure they did away with the headlights in the design phase.
06-09-2000, 03:58 AM
I specifically recall seeing Apollo missions in orbit. I remember reading info in the newspaper that said when the orbiting command module and lunar modules (linked together) would be visible from a particular spot on earth. It looked like any other satellite, a little blip of light.
But more to the point of the question, I don't recall seeing the Apollo once it had left earth orbit, on its way to the moon. And I definitely would have looked (and remembered!) if there had been any way to view it.
Most likely, the ship would have been hard to distinguish from a background star once it left earth orbit. Its easy to spot a satellite in earth orbit, they move against the background stars, but a satellite headed for the moon is travelling in a basically straight line away from the observer, it would look like a fixed star, if it was visible at all.
06-09-2000, 07:45 AM
>Most likely, the ship would have been hard to distinguish >from a background star once it left earth orbit. Its easy >to spot a satellite in earth orbit, they move against the >background stars, but a satellite headed for the moon is >travelling in a basically straight line away from the >observer, it would look like a fixed star, if it was >visible at all.
That's a very good point!
06-09-2000, 09:29 AM
Madd1--no, there were no external lights. Both vehicles had windows, so some light would escape from there, but not enough to be seen from Earth.
06-09-2000, 05:24 PM
When Apollo 13's oxygen tank exploded the expanding gas and debris could be seen with ground based telescopes.
06-09-2000, 07:19 PM
Just thought some of you might enjoy this link
It is a piece of NASA software for tracking sattelites
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