So, who wants to win 1 million Euro?

[Noldi400]

On GLP there are currently a bunch of folk who refuse to understand that the mass of an asteroid (specifically 2012 DA14) is irrelevant to its orbit.

[devil's advocate]So if the moon was much more massive than it is in reality, say, it was the same physical size that it is now, but had the mass of Jupiter, it would trundle along happily in it's current orbit around the Earth; 29.53 days at at distance of 384,000 km? Really?[/devil's advocate]

I may have dropped a decimal point, but wouldn't the density be getting close to black hole levels?

[raven]

Close, but not reaching, considering a black hole the mass of the sun would be, if I remember correctly, only few miles wide.

[Glom]

But if the Moon was that large, the two body problem becomes less anchored. We have to start considering the orbit of both bodies about the barycentre.

[Echnaton]

I have always though that the combined mass of both objects defined the orbit.  It is just that in most cases the mass of a space craft or asteroid is an insignificant component to the combined mass.  Is that not correct?

[cjameshuff]

I have always though that the combined mass of both objects defined the orbit.  It is just that in most cases the mass of a space craft or asteroid is an insignificant component to the combined mass.  Is that not correct?

That's correct. The period is 2*pi*sqrt(a^3/(G*(M1 + M2))). When M1 is many times M2, you can simplify M1 + M2 to M1 with little loss of accuracy. And a 1 trillion tonne object is still 70 million times smaller than the moon...the loss of accuracy from this simplification is likely to be less than the precision of your computations.

[ipearse]

I just had a look at some of the DA14 threads on GLP.  I am stunned not only at the wilful ignorance but at the appalling abuse.  I feel a bit sick

Linky? Please don't make me search GLP for it.

There are two pages of DA14 threads over there. Have one at random. NASA dunnit http://www.godlikeproductions.com/forum1/message2139821/pg1

Apparently, my IP address has been banned from GLP...? Mind you, from what I have heard of the place, I think it's a blessing in disguise!

[smartcooky]

I have always though that the combined mass of both objects defined the orbit.  It is just that in most cases the mass of a space craft or asteroid is an insignificant component to the combined mass.  Is that not correct?

That's correct. The period is 2*pi*sqrt(a^3/(G*(M1 + M2))). When M1 is many times M2, you can simplify M1 + M2 to M1 with little loss of accuracy. And a 1 trillion tonne object is still 70 million times smaller than the moon...the loss of accuracy from this simplification is likely to be less than the precision of your computations.

Right, so it isn't strictly speaking true that the mass of an object does not affect its orbit, its just that with the huge disparity between the solar mass and asteroid's mass, the difference is so insignificantly small that it will make no appreciable difference.

Of course the mass of the asteroid could be significant should it encounter some other solar system object, right? e.g., an asteroid with the mass of a small car will suffer greater orbital perturbation than one half the mass of the moon were either of them to pass close to Jupiter on their way to the Sun?

[cjameshuff]

Of course the mass of the asteroid could be significant should it encounter some other solar system object, right? e.g., an asteroid with the mass of a small car will suffer greater orbital perturbation than one half the mass of the moon were either of them to pass close to Jupiter on their way to the Sun?

The difference is still slight. Jupiter still outmasses the larger object by 50 thousand times. And you have the effect reversed...the larger object will be influenced more, because its attraction will accelerate Jupiter toward it.

[onebigmonkey]

That's correct. The period is 2*pi*sqrt(a^3/(G*(M1 + M2))). When M1 is many times M2, you can simplify M1 + M2 to M1 with little loss of accuracy.

Yeah. Yeah, er, yeah. I was thinking that would be it.

[Peter B]

The things you find out watching the "Toy Story" movies... 

(Just bought them for the boys, and I'm happy to admit that I enjoy all of them too.)

Each DVD has a 3 minute NASA film about the International Space Station. On one of them I noticed an astronaut come inside after a spacewalk who had a Swedish flag on his arm.

I wonder if Anders Bjorkman would accept the word of fellow Swede Christer Fuglesang that it's possible to safely return to the Earth from the ISS?

http://en.wikipedia.org/wiki/Christer_Fuglesang

[carpediem]

I wonder if Anders Bjorkman would accept the word of fellow Swede Christer Fuglesang that it's possible to safely return to the Earth from the ISS?

http://en.wikipedia.org/wiki/Christer_Fuglesang

I'm going to take a wild stab in the dark, and go with no, he wouldn't.

[twik]

Arguments become so easy to win, when you have two buttons to press: "They faked it," and "He's lying". I'm sure Heiwa would simply press Button #2 for Mr. Fuglesang's testimony.

Then, of course, if Mr. F. were to claim he was not lying, and gave evidence, such as photos, reports, and other documents, Heiwa can press Button #1 for that.

It's a two-note symphony.

[Peter B]

I wonder if Anders Bjorkman would accept the word of fellow Swede Christer Fuglesang that it's possible to safely return to the Earth from the ISS?

http://en.wikipedia.org/wiki/Christer_Fuglesang

I'm going to take a wild stab in the dark, and go with no, he wouldn't.

 

Yep, but at least they can argue in Swedish and leave us alone...

[Sus_pilot]

I wonder if Anders Bjorkman would accept the word of fellow Swede Christer Fuglesang that it's possible to safely return to the Earth from the ISS?

http://en.wikipedia.org/wiki/Christer_Fuglesang

I'm going to take a wild stab in the dark, and go with no, he wouldn't.

 

Yep, but at least they can argue in Swedish and leave us alone...

"Ya, hey dere, you faked, da whole ding, you hoser."

Sorry, Northern Illinois boy here. I keep channeling the Norwegians and Swedes from the Upper Peninsula...

[Daggerstab]

Anders "quietly moving the goalposts" Björkman has modified his page again, last on 28 Feb. This time, a lot of the text has been shuffled around, so it's harder to find novel changes, but still not impossible.

http://www.members.tripod.com/heiwaco/moontravel.htm

Based on his usual simplistic calculations, he proclaims the Ariane 5 to be real and the Saturn 5 and the Shuttle fake. Oh, and as for this:

It is always nice to compare old and new space vehicles carrying out maneuvers and the fuel consumed. And the conclusions is clear! NASA fakes it. 44 years ago 1969 and today 2013. Only the French Ariane 5 is real!

(The emphasis is his.) Psst, dude, the Shuttles fly no more, so what exactly are NASA faking in 2013?

(He again tries to deduce the "fuel consumption" per joule from the vehicle loadout at start and the payload's orbital velocity, gets a low value for the Ariane, then decides that this is a "real" value as compared to his Apollo numbers. Hey, Heiwa! Why don't you go to the scientists and engineers that designed and built the Ariane and ask them if Apollo was real? Even better, show them your "calculations". Even engineers enjoy a laugh now and then. )

Björkman has also quietly accepted the existence of a Shuttle orbiter re-entry sonic boom, migrating from "Anyone hearing a Shuttle producing a sonic boom at re-entry was therefore mistaken. Or subject to NASA propaganda!" and "And no sonic booms!" to the orbiter making "a short supersonic flight to produce a sonic boom" after being released from an airplane and speculations about the overpressure levels of the shockwave.

Oh, and he's added another picture, of a Shuttle re-entry from the ISS:

Above NASA photo (http://www.nasa.gov/images/content/573233main_image_2014_946-710.jpg) shows the space shuttle Atlantis, appearing like a bean sprout against clouds and city lights, on its way home braking through the atmosphere, as outlined above and below. It was allegedly taken by the Expedition 28 crew of the International Space Station. Airglow over Earth can be seen in the background. The photo does not look real in my view, i.e. it is another fake.

  Ever heard of "long exposure", Björkman? Oh, and as for another newly added jab, shuttle re-entries can be seen from the ground, too. Remember the thermal camera imaging of Columbia?