Here's a nice website with a photo of Apollo 13 on the way to moon

http://www.w7ftt.net/apollo13.html

I think there's a photograph of Apollo 13 took during the explosion, but I'm not sure where it is. I think it has been posted here before.

__________________
~AstroMike

Never mind, found it.

http://www.flash.net/~imagine5/apoll...13Mission.html

__________________
~AstroMike

The explosion was actually viewed from the ground as it happened:

"Although it was the middle of the day at Honeysuckle Creek, around at Houston it was just after 9 pm on a pleasant clear evening. With three friends, Andy Saulietis had rigged up a telescope connected to a black and white television set on a roof of the Manned Spacecraft Center. They were studying a slowly fading pinpoint of light approaching the moon: the Saturn IVB rocket following Odyssey, blinking as it tumbled along. While they watched, a bright spot appeared in the middle of the screen and over the next ten minutes grew into quite a bright ball. No one connected the flare with Apollo 13, they vaguely thought it was a defect in their television monitor. They left the rooftop quite oblivious to what they had witnessed: the oxygen tank on Apollo 13 exploding, and in ten minutes spreading into a gaseous sphere over 30 miles (48 km) wide, glowing in the sunlight."

http://www.tip.net.au/~jsaxon/space/book/After11.htm


<font size=-1>[ This Message was edited by: Peekaboo on 2002-07-09 19:46 ]</font>

I find this somewhat difficult to believe- a 16" telescope having the resolution to show a spacecraft nearly 200,000 miles away.
If it could then it'd seem that the Hubble would be able to easily show the Apollo remnants on the moon.
Maybe Mr. Plait wouldn't mind making a comment, since he's a professional astronomer.


CzC

Don't mix resolution with just the ability to recognize a spot of light. The human eye has an angular resolution of around 1 arcminute (the Moon's angular diameter as seen from Earth is some 30 arcminutes). The angular diameter of stars is very, very small, a few milliarcseconds and below. But you can see them, as enough photons from the stars reach your eyes. That doesn't mean that you can see any details.
I guess you wouldn't need a very bright light source mounted on top of the LM descent stage to recognize this with a telescope when the stage is in the dark.

Harald

<font size=-1>[ This Message was edited by: kucharek on 2002-07-10 02:59 ]</font>

The 16" Meade LX200 (I want one) has a resolution power of .28 arc seconds, at 200,000 miles wouldn't that make the CSLM about .5 km?

What are the S-IVB rockets doing that close to the CSLM at 200,000 miles away?
I thought they were jettisoned before transposition/docking. I don't know, it just looks implausible to me.

The SIV-B stage was left after T&D and followed nearly the same trajectory, so it's reasonable that viewed from Earth they are nearly at the same place in the sky.

Harald

<font size=-1>[ This Message was edited by: kucharek on 2002-07-10 09:56 ]</font>

The separation maneuver is on the order of 10 fps. It doesn't matter so much that they're very far away as it does that their trajectories continue to diverge. And keep in mind that while the angular difference between the two might seem very narrow in a particular view from earth, one spacecraft may actually be signficantly farther away from the viewer than the other.

According to this the S-IVB impacted the lunar surface almost 2 hours before the Apollo 13 explosion. If I'm not misunderstanding the page, the S-IVB couldn't even be in that photo. Although it doesn't say UT after 01:09:41.0, I'm assuming that it is UT.

"It impacted the lunar surface on 14 April at 01:09:41.0 at 2.75 S, 27.86 W with a velocity of 2.58 km/s at a 76 degrees angle from horizontal.)"

"A television broadcast was made from Apollo 13 from 02:24 UT to 02:59 UT on 14 April and a few minutes later, at 03:06:18 UT Jack Swigert turned the fans on to stir oxygen tanks 1 and 2 in the service module."

http://nssdc.gsfc.nasa.gov/database/...g?sc=1970-029A


CzC

Nope. Impact was long after the explosion. Seems to be a typo (14/15). According to "Apollo by the Numbers":
http://history.nasa.gov/SP-4029/Apollo_13h_Timeline.htm

CMP: "Okay, Houston, we've had a problem here."
055:55:20 GET 03:08:20 GMT 14 Apr 1970

S-IVB impact on lunar surface.
077:56:40.0 GET 01:09:40 GMT 15 Apr 1970

Harald

ah 13: pretty high ratings would be my guess?
Don't get me wrong? When i was a kid, Rocket Man
was by far my most favorite "SERIAL" and kept
me in a theater seat each Saturday {for the matinee}
Anyway: No i dont have the most watch TV eposoid
ever or the top 10 or 20. I would think 13 would
be in there somewher. From the first ANNOUNCEMENT
"Houstin" We have a problem.. ..i for one thought
to myself Uh hU Made For Prime time.. and never had
even a secon of doubt from Ho on that it
wold end happly ever on the day after day
DOC.U.ment:eatery.. oh my.. well so much for
my view of the made for PRIME TIME TV:
now back to the 4AM special's
http://www.pbs.org/cgi-registry/what...f&d=2002-06-23

I didn't know NASA was making this claim.
It does give it a little more credibility, I'll admit.

But, if the gas cloud is 30 miles wide and the CSM scaled next to it, to me it looks like the CSM would be about a mile long. But that's just me and my pea brain.

CzC

Using this argument, it should be impossible to see stars through a telescope, as they are point light sources. Maybe stars are a hoax?

I'm sorry, I assumed you couldn't see all the stars in universe with a 16" SCT. I was thinking that distance and high magnitude prevented that.

Using your logic, a shiny new dime jettisoned from the CSM 200k miles should be viewable by telescope. Distance and size is a factor in trying to resolve an object through a telescope, I don't care how much light it reflects.

CzC

But at the distance to the nearest star, no matter what size telescope you use, they always show a point source of light, never a disk. Therefore, the angle seen by the telescope is essentially zero. Remember also that the photo is a timed exposure, so things will have moved during the exposure.

CzC, you're still confusing viewability of light with resolvability of an object. Viewability of a light source is only a matter of how many photons from it reach your eyes, it is not depending on some angular diameter. Resolvability is a matter of angular diameter. That's why we can see stars very, very far away, even very small ones - because they crank out lots of photons, but we cannot view planets orbiting other stars, even when the are huge, because not many photons - of course reflected from their sun - are reaching us.
Think of someone who stands on a plane 5 miles away from a mountain. If someone climbs up the mountain, you may not be able to see him because he is too small. But when he lights a flashlight at night, you will see that spark of light.

Harald

But there's the problem, we don't know the brightness of the CSM. There's a link in this thread where someone with a 24" telescope tracked the Apollo 13 C/S/LM doing it's trans/dock using the jettisoned S-IVB. At the time the claim was made that the SIVB was a mag. 13. Now we look at the 16" SCT pic, 2 days later and almost 200,00 mi. farther. The SIVB is brighter than the CSLM, I doubt that it would still be a mag. 13 and the CSLM is a lot dimmer and with a scope (16" SCT) with 50% less light gathering capabilities than the 24". The 16" LX200 has a visual mag limit of 15.5.

But if anyone can find me an image of the clementine satellite, taken with a 20" scope or smaller, I'll gladly concede this point.

CzC

As long as you don't know all the parameters, it's very difficult to compare two photographs. One is a 5 minute exposure, the other taken with a tv-camera and photographed off some monitor, if I understand correctly. Maybe that camera had some low-light amplification stuff and the photo was also enhanced etc. So you can't say, the S-IVB is brighter in one than on the other photograph.

Regarding Clementine: Much smaller and less shiny than a CSM.

Harald

<a name="20020711.3:14"> page 20020711.3:14 aka several hours from now
now back to the 4AM special's
[54]http://www.pbs.org/cgi-registry/whatson/template.cgir?s=KOPB&t=0&c
Read 27358 bytes of data.
midnight [409]Charlie Rose
1:00am [410]Rich Dad, Poor Dad
2:30am [411]Short List
3:00am [412]Newshour With Jim Lehrer
4:00am [413]People's Century "1930: S
5:00am [414]Nightly Business Report

BTW:
-I'm not clear what do you want to say with the above (sorry, I'm no native speaker).
-Are you going to tell GSFC about the glitch or should I do it?
-The entry in the page for the S-IVB is correct:
http://nssdc.gsfc.nasa.gov/database/...g?sc=1970-029B

Harald

<font size=-1>[ This Message was edited by: kucharek on 2002-07-11 10:51 ]</font>

Well, I looked at the A13 photo Astromike linked to. I look at the point of the arrow labelled "O2 cloud", and all I see is black space.

Can I assume there's something visible in higher resolution versions of that photo, cos I'm darned if I can see anything you could call a cloud in that version of the photo.