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Radar reveals two moons orbiting asteroid Florence

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Re: Radar reveals two moons orbiting asteroid Florence

#31

Post by verytrivial »

jaquers wrote: post #2

Is the 'light' reflecting off the asteroid emitted from the sun? I had never seen or even knew radar could distinguish value like what is shown here. I suppose terrestrial radar looks at much smaller objects and what it sees is emitted from the tower and bounced back in a straight line so that sort of makes sense. More info on the observatory: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar

Phil Plait to the rescue! http://www.syfy.com/syfywire/close-encounter-by-the-big-aste...

Edit: I think it might be helpful to view this more like ultrasound image than a photograph. There is no "side" view. It has been reconstructed based upon the time it takes for the bounce to return.

Re: Radar reveals two moons orbiting asteroid Florence

#34

Post by russdill »

labster wrote: post #16
arihant wrote: post #15

Earlier quoted context omitted.

If we go grab a moon sized ball of gold, gold will lose most of its value. It'll be the next Aluminium.

That much gold would still be worth it for electronic and spaceflight applications. Gold's like a better copper or silver there. And let's not forget the most important application, stereo plug connectors. For platinum or iridium, making it cheaper there would enable all sorts of catalytic chemical processes that are prohibitively expensive now. If abundant enough, new demand will keep the bottom of the market from f…

They actually just plate connectors typically, I think with around 7µm of gold. And no, gold is not a better copper or silver. Both silver and copper are more conductive than gold (then followed by aluminum).

Gold is excellent for contact points though as it does not tarnish.

Silver conducts heat and electricity the best of the three, but tarnishes the most easily, so it can have issues with high frequency signals as most of the signal travels on the outer surface.

If both silver and copper were the same price as copper, it'd probably be silver that would see the most increase in use in electrical applications. During the Manhattan project, there was a shortage of copper and cost was not an option. 430 million troy ounces of silver from the West Point Bullion Depository was melted down and used to make magnetic coils. At the end of the project, it was all returned, minus 120 oz.

https://en.wikipedia.org/wiki/Calutron

Re: Radar reveals two moons orbiting asteroid Florence

#35

Post by kamaal »

arihant wrote: post #15
SCAQTony wrote: post #5

Imagine hijacking a 100-meter moon made of rare earth metals like gold, platinum, rhodium, ruthenium, iridium, etc. etc. More than enough to under write the mission and pay for a moon base.

If we go grab a moon sized ball of gold, gold will lose most of its value. It'll be the next Aluminium.

1. Firstly they won't be sending it down a gravity well, unless of course there is need for it. And if they really do send it they will likely strictly control its supply. Economics today is quite well done. Even blood diamond miners restrict supply to ensure demands.

2. They will likely be using mined material from asteroids to build space stations and bases.

3. They will only mine as much as they need, given an how much of it is available.

Its like expansion of human cities you extract/mine as much as you need and when you need it.

Space economics is a crazy thing, once you start thinking about it. The first people to start building in space will ponder the vastness and almost a infinite space full of resources and real estate to occupy. Of course the concept of ownership will look ridiculous. This is at least until there is a rapidly growing and spreading population in space.

Beyond that its really how quickly you can spread out. And the economics of that is not money. But trading energy for longevity.

I can assure you we are a very long time away from spreading to the last inch of the universe.

Re: Radar reveals two moons orbiting asteroid Florence

#36

Post by [deleted] »

labster wrote: post #16
arihant wrote: post #15

Earlier quoted context omitted.

If we go grab a moon sized ball of gold, gold will lose most of its value. It'll be the next Aluminium.

That much gold would still be worth it for electronic and spaceflight applications. Gold's like a better copper or silver there. And let's not forget the most important application, stereo plug connectors. For platinum or iridium, making it cheaper there would enable all sorts of catalytic chemical processes that are prohibitively expensive now. If abundant enough, new demand will keep the bottom of the market from f…

[deleted]

Re: Radar reveals two moons orbiting asteroid Florence

#38

Post by wiredfool »

jaquers wrote: post #2

Is the 'light' reflecting off the asteroid emitted from the sun? I had never seen or even knew radar could distinguish value like what is shown here. I suppose terrestrial radar looks at much smaller objects and what it sees is emitted from the tower and bounced back in a straight line so that sort of makes sense. More info on the observatory: https://en.wikipedia.org/wiki/Goldstone_Solar_System_Radar

Here's a good explainer on what you're actually seeing in the radar image: http://www.planetary.org/blogs/emily-lakdawalla/2011/3248.ht...

* The signal is emitted from a radar installation on the earth, and reflected back to another dish.

* Brightness is reflected signal strength. So surfaces that are perpendicular to us will reflect better. The less the surface normal points to us, the less reflection we see.

* Up/Down is Time axis. The points closer to us will return sooner than points farther away.

* Left/right is Doppler shift. Parts of the asteroid that are rotating away from us will show up on one side, parts rotating towards us will show up on the other side.

(this is the vertically oriented image).

Re: Radar reveals two moons orbiting asteroid Florence

#39

Post by dalbasal »

arihant wrote: post #15
SCAQTony wrote: post #5

Imagine hijacking a 100-meter moon made of rare earth metals like gold, platinum, rhodium, ruthenium, iridium, etc. etc. More than enough to under write the mission and pay for a moon base.

If we go grab a moon sized ball of gold, gold will lose most of its value. It'll be the next Aluminium.

Gold is peculiar in this sense, but generally speaking I think it’s worth separating value from price

If we doubled oil supply tomorrow, the price would drop drastically, probably to less than half. The total price of all the oil would be less than yesterday. But, that doesn’t mean we’re deriving less value from the oil. We’ll have more energy and materials, that’s more value. It probably isn’t twice the value (we’d probably be less energy efficient, for example) but it would definitely be more value.

Re: Radar reveals two moons orbiting asteroid Florence

#40

Post by ceejayoz »

radicalbyte wrote: post #22
Lordsandwhich wrote: post #7

Earlier quoted context omitted.

I was always under the assumption that with Radar images that it didn't rely on a light source as technically the radar is the source. So that the impression that there is a light an dark side was based purely on the motion towards and away from the receiver. But, you have pointed out something interesting and that would appear to indicate other wise. The clear rotation independent of source already shows that I am w…

This thread is very confused. There are two things: the radar images are created with radio waves emitted by the radar installation. The second thing is that the visualisation shows a light source. They are unrelated to each other. I assume that the light source was added during rendering of the film and that it approximates the sun.

The radar is the light source, just like shining a flashlight during the night at something.

The actual solar illumination of the asteroid at the time was likely significantly different from what we see in these images.

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