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Old 04-03-2008, 19:39
Trinitrotoluene
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Yes, there's no convincing some people, is there? We've been accurately measuring the distance from the earth to the moon for some time now using lasers bouncing off reflectors on the moon's surface. The reflectors didn't get there by themselves...
They did actually. The soviets landed Soviet Lunokhod 1 and Lunokhod 2 rovers, Lunokhod 2's retroreflector still works to this day.

EDIT: I know you are talking about the Apollo retroflectors, but this is the argument that all HB's use back
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Old 04-03-2008, 19:45
Ricardodaforce
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I'm pretty sure it was. What makes you think otherwise?
There's just no way the Earth and the Moon would appear that big in the Martian sky.
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Old 04-03-2008, 19:54
ElMarko
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There's just no way the Earth and the Moon would appear that big in the Martian sky.
They would with the zoomed in image from, say, an orbiting Martian imaging craft...
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Old 04-03-2008, 19:57
Mandark
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There's just no way the Earth and the Moon would appear that big in the Martian sky.
This is what the text said. The orbiter has a telescopic camera.
The High Resolution Imaging Science Experiment (HiRISE) camera would make a great backyard telescope for viewing Mars, and we can also use it at Mars to view other planets. This is an image of Earth and the moon, acquired on October 3, 2007, by the HiRISE camera on NASA's Mars Reconnaissance Orbiter.

At the time the image was taken, Earth was 142 million kilometers (88 million miles) from Mars, giving the HiRISE image a scale of 142 kilometers (88 miles) per pixel, an Earth diameter of about 90 pixels and a moon diameter of 24 pixels.
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Old 04-03-2008, 20:00
Eraserhead
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They did actually. The soviets landed Soviet Lunokhod 1 and Lunokhod 2 rovers, Lunokhod 2's retroreflector still works to this day.

EDIT: I know you are talking about the Apollo retroflectors, but this is the argument that all HB's use back
Ah, I stand corrected. Thanks for the info. Still, the conspiracy nuts probably won't accept any evidence as genuine.
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Old 04-03-2008, 20:08
Ricardodaforce
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They would with the zoomed in image from, say, an orbiting Martian imaging craft...
That makes more sense!
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Old 04-03-2008, 20:25
Trinitrotoluene
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This is what the text said. The orbiter has a telescopic camera.
Quick, dirty calculations:

Distance to Earth in metres: 142000000000
Diameter of Earth in metres: 12756000

Angular size of Earth from mars = Diameter of Earth / Distance to Earth

Angular size = 8.9830985915492957746478873239437e-5

In degrees = (8.9830985915492957746478873239437e-5) x 180 / Pi = .0051469363 degrees across.

In arcseconds, 18.53 (2dp). At 90 pixels, that is 4.86 pixels per arcsecond. Seems perfectly feasible to me.
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Old 04-03-2008, 21:02
Carlos_dfc
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Surprised no-one has mentioned it in this thread yet.....

But today is Patrick Moore's birthday

Happy Birthday PM
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Old 04-03-2008, 21:23
swingaleg
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I guess we all watched the stephen hawking documentary last night ?

I'm always a bit disappointed by these 'stephen hawking' shows...............I'm still not sure what his theory was that was so fantastic..........I mean, he's not really in the Newton/Einstein class is he ?..........but they always seem to indicate that he is.


As far as I know his main claim to fame is the 'radiation' from black holes, but surely that's just a step...... lots of scientists must have made contributory steps to a greater understanding.........Penrose did all the hard sums.

Isn't the truth that he's not that great, he's just one amongst a crowd, each making their own small contributions to a greater 'whole'...........he's not rewriting physics in the way Newton/Einstein did..........
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Old 04-03-2008, 22:09
Ricardodaforce
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Very controversial!
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Old 05-03-2008, 00:03
Mandark
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Surprised no-one has mentioned it in this thread yet.....

But today is Patrick Moore's birthday

Happy Birthday PM
Oh I forgot. Late happy birthday. I met him 26 years ago and he had white hair then!!!
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Old 05-03-2008, 00:21
Mandark
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I guess we all watched the stephen hawking documentary last night ?

I'm always a bit disappointed by these 'stephen hawking' shows...............I'm still not sure what his theory was that was so fantastic..........I mean, he's not really in the Newton/Einstein class is he ?..........but they always seem to indicate that he is.

As far as I know his main claim to fame is the 'radiation' from black holes, but surely that's just a step...... lots of scientists must have made contributory steps to a greater understanding.........Penrose did all the hard sums.

Isn't the truth that he's not that great, he's just one amongst a crowd, each making their own small contributions to a greater 'whole'...........he's not rewriting physics in the way Newton/Einstein did..........
You make an interesting point. There's a difference between celebrity and true greatness.

I've read several interviews with well known physicists who have given their views on Hawking. I think all of them said there were other more important living physicists than Hawking. Ed Witten is probably as good as they come at the moment.

But I think why Hawking is celebrated is that he has still managed to remain a top physicist despite his disabilities. But if they ever find the grand unified theory and look back at everybody's contribution towards it, his contribution probably won't stand out. I think it's generally accepted that no one alive appears to be in the Newton/ Einstein class. But then that's one hell of a class!
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Old 05-03-2008, 11:27
Ricardodaforce
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Oh I forgot. Late happy birthday. I met him 26 years ago and he had white hair then!!!

Yeah I hope he had a good one. I think the guy's a legend in some ways.
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Old 05-03-2008, 11:53
ChristineCagney
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You make an interesting point. There's a difference between celebrity and true greatness.

I've read several interviews with well known physicists who have given their views on Hawking. I think all of them said there were other more important living physicists than Hawking. Ed Witten is probably as good as they come at the moment.

But I think why Hawking is celebrated is that he has still managed to remain a top physicist despite his disabilities. But if they ever find the grand unified theory and look back at everybody's contribution towards it, his contribution probably won't stand out. I think it's generally accepted that no one alive appears to be in the Newton/ Einstein class. But then that's one hell of a class!
I think this is why. He wasn't expected to live as long as he has - about 40 years more than they predicted. Good post.
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Old 05-03-2008, 15:36
Mandark
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Talking of physics I quite enjoyed that series on the history of the atom. I agree with the presenter's ending that the next challenge for scientists is to work out how these strange objects all link together and create living thinking beings.
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Old 05-03-2008, 18:09
Baldrick Phd
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What an excellent thread - now bookmarked.

Thanks to all those who posted links to books, photos, space sites etc. My bookmark folder is now overflowing and I think I'll be off to Amazon for the next 6 months reading material.

I don't know why it took me so long to post on here as I've been fascinated by space ever since watching the Apollo missions. Strangely I can't remember Apollo 11, my first recollection was probably Conrad and Bean on Apollo 12 although I can clearly remember watching Apollo 13 'as it happened'
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Old 05-03-2008, 18:30
Eraserhead
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I think this is why. He wasn't expected to live as long as he has - about 40 years more than they predicted. Good post.
Yes I think he'll be remembered in future more for his struggle against his disability than for any great advances in physics or cosmology.

What Hawking has done, though, is to push the very dry and complex world of physics into the wider public consciousness and made it accessible to the layman (although he's by no means the first to do this, e.g. Carl Sagan.)

He's become a popular figure of cosmology in a similar way that Richard Dawkins has with evolutionary biology.

It's a moot point whether he deserves such a high place in his field of work but the history of science is riddled with people who have achieved fame and success (and Nobel Prizes) while others who had previously discovered the same things or contributed to their discovery get ignored.
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Old 05-03-2008, 18:42
Ricardodaforce
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A recommendation or two for those who really are interested in the Apollo missions.

Al Reinert's superb documentary For All Mankind. Lovely Brian Eno soundtrack by the way.

Tom Hanks's HBO mini-series From the Earth to the Moon.

Both highly recommended!
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Old 05-03-2008, 19:14
BeethovensPiano
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http://www.spaceflightnow.com/news/n0803/03ecliptic/

The NASA-funded Lunar CRater Observation and Sensing Satellite (LCROSS) mission is designed to impact the LCROSS spacecraft (and a large upper stage from the Atlas 5 rocket that launches it) into a permanently shadowed crater at the Moon's south pole in early 2009. LCROSS and another NASA spacecraft, the Lunar Reconnaissance Orbiter, will be launched by the same Atlas 5 in winter 2008.
Employing an active, pre-defined and extensively rehearsed sequence stored in and executed by the DHU, the LCROSS science payload will first observe the Atlas 5 upper stage impact into the crater, followed a few minutes later by direct observations of the 250-metric-ton plume of material ejected from the crater by this first impact as it meets the incoming LCROSS spacecraft about 10 km above the lunar surface. Finally, LCROSS will capture its own demise as it, too, impacts the same crater. Live RocketCam video and science data will be beamed back to Earth-bound viewers throughout this approximately 9-hour sequence of events. Numerous terrestrial and space-based telescopes should be able to observe the impacts as well.
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Old 05-03-2008, 19:19
Eraserhead
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Interesting...but, forgive my ignorance, what is this "suicidal" mission setting out to achieve?
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Old 05-03-2008, 19:23
Ricardodaforce
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Interesting...but, forgive my ignorance, what is this "suicidal" mission setting out to achieve?
This was featured on The Sky at Night. Think of the data that come from analysis of the plume and ejecta.
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Old 05-03-2008, 19:28
BeethovensPiano
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Interesting...but, forgive my ignorance, what is this "suicidal" mission setting out to achieve?
Answers here: http://lcross.arc.nasa.gov/faq.htm

What is the primary mission goal of LCROSS?

There is evidence from previous missions for enhanced hydrogen deposits at the poles of the Moon. Due to limitations in the data sets that measured this hydrogen, we still do not know the form of the hydrogen, that is, is it in the form of water (H2O) or some other hydrogen-bearing compound, such has hydrated minerals or hydrocarbons. One possibility is that the hydrogen is indeed in the form of water (as ice, ice-coated dust grains, and/or hydrated minerals) and it is accumulating in craters whose floors are in permanent shadow, and so very cold: only 60 °C (110 °F) or so above absolute zero. LCROSS will make the first definitive measurements for water within a permanently shadowed crater. Using a suite of instruments, including infrared and visible spectrometers and cameras, LCROSS will be able to identify water (ice, ice-coated dust grains, or vapor) in the impact ejecta cloud and, hopefully, shed some light (pun intended) on this question.
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Old 05-03-2008, 19:31
ChristineCagney
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A recommendation or two for those who really are interested in the Apollo missions.

Al Reinert's superb documentary For All Mankind. Lovely Brian Eno soundtrack by the way.

Tom Hanks's HBO mini-series From the Earth to the Moon.

Both highly recommended!
Funnily enough I was watching From the Earth to the Moon last night. It's really very good!
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Old 05-03-2008, 19:51
Ricardodaforce
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Funnily enough I was watching From the Earth to the Moon last night. It's really very good!

oooooooooooooo spooky
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Old 05-03-2008, 19:53
Eraserhead
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Interesting...but, forgive my ignorance, what is this "suicidal" mission setting out to achieve?
^^

Thanks for the replies to this question.
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