Poisson statistics. I have to wonder if Mr. Haselton has ever heard of the term.
If by some weird alignment of forces I were to become a Judge, and Mr. Haselton presented this to me in a brief, I would try and have him disbarred for abuse of statistical process. I know that the actual legal profession is soft about such abuses, but by God they wouldn't be in my courtroom.
Not to mention that they don't know where the lander is.
I think it is a safe bet it will be found. They have the photos from the surface, they have the CONSERT triangulation, and of course they have a great desire to find it (and the comet isn't that big). It will be found.
Sadly, while the "weight" is very small on the comet, it's mass (and therefore inertia) is substantial. You're not going to blow it over.
I am going to ignore for now any issues of damage from nearby thruster firings.
Rosetta has 24 bipropellant 10 N thrusters and is 2.8 x 2 m, not counting solar panels. Philae is 1 x 1 x 0.8 m. Suppose Rosetta fires a thruster from 3 meters away - Philae is then 1/3 of a radian across, or about 0.1 steradians. Suppose the thruster has a exit angle of 2 pi steradian (i.e., the whole hemisphere away from the spacecraft, which is surely conservative). So, I would expect Philae to experience a force of 10 N x 0.1 / 2 pi ~ 0.2 N. It has a mass of ~ 100 kg, so that would impart a thrust of 2 x 10^-3 m/sec^2. (I am assuming Rosetta has a thruster firing on the opposite side too, so it's not moving.) That is actually greater than the 67/P gravity, so Philae could move. If this were done for say 10 seconds, Philae would have a velocity of ~ 1 cm/sec afterwards and maybe a total flight time of 30 seconds. Now, it wouldn't move far, but it might get to a little flatter terrain and maybe more sunshine.
It wouldn't surprise me if they land Rosetta on the comet toward the end of the mission.
That is indeed under discussion.
From Valerie Lommatsch, an engineer at the Lander Control Center at DLR in Germany
"It is very unlikely right now. We have 1.5 hours [of sunlight] at less than 1 watt, and 20 minutes of 3 or 4 watts. The lander needs 5 watts to boot....In order to charge the secondary battery, we have to heat it to 0 degrees Celsius. We need about 50-60 watt-hours a day in order to reach 0 degrees and still have daylight left to charge the battery. So it doesn't look that great. What we could hope for is if we are closer to perihelion, near 1 AU, maybe we could have enough energy on our one solar panel, maybe every once in a while"
So, they need 50 watt hours, and they are maybe getting 2. Now, this was before the 30 degree rotation, but I don't think that's going to get them a factor of 20 improvement. Maybe that, plus doing through perihelion, can do it.
I wonder if they couldn't get Rosetta near Philae, and use the reaction jets on Rosetta to move it (i.e., by blowing on it). Philae only weighs about as much as ping-pong ball; it wouldn't take much to move it away from where it is.
While the Philae team is sleeping, nefarious malefactors are busy selling Philae on eBay. It's up to five pounds sterling as I write. Maybe we should wake them up.
1. As the comet approaches the sun, is it likely that the angle of or proximity to the sun will provide enough light to make a difference?
2. I assume we've measured whether Rosetta is rotating, even slightly. Is there a chance that this will help (or hurt) Philae's chances at coming back on line?
3. As the comet gets closer to the sun, I imagine that it will start melting/vaporizing (this being what makes a comet look like a comet in the first place). Since Philae is not firmly anchored (and that might not make a difference in any case), what do we expect to happen, and when?
1.) Maybe.
2.) If you mean Comet P/67, maybe.
3.) Maybe, pretty much anything up to and including ejecting Philae away from the comet for good. As for when, maybe around perihelion (13 August 2015) when activity is highest. Or, maybe before then. Or after then.
Glad I could help clear things up!
If I had to guess, I would bet that sugar or corn syrup is being used as a chocolate extender.
They are a big player, because they need a lot of chocolate, and futures help to manage their acquisition prices. Of course, they could try to play with the market, but they'll risk alienating their chocolate eating customers, so it's not clear that this would be in their advantage.
Well, of course. They are the sort of player the futures markets were invented for (they KNOW they will need cocoa in the future, they KNOW more or less how much, why not hedge the price if the opportunity presents itself?). It's just my cynical side wakes up whenever I hear a big futures player start jawboning the market.
It's probably worth mentioning here that Mars, Inc. is one of the big players in the Cocoa futures market. This is not investment advice, but if you invest in cocoa futures based on this article, you would be making a bet based on a story from someone who hopes to make money off of you.
It is an axiom of sales that delays will always mean that some will give up. Whether it's a 5 second wait for a web page to load, or a 5 month wait for a new computer, a delay always means you will lose some customers.
You would have to be pretty stupid to think that this matters a damn.
Doesn't the field move around too fast for it to be tightly coupled to the mantle? For example, look at the motion of the magnetic poles - surely hot spots in the mantle are not moving 50 km / year.
As someone who works in Dark Matter, I have to say I am glad that the brand has now reached the point that scientists in other fields appropriate it, apparently purely as a branding mechanism. I mean, I hate to be pedantic, but magma at 3200 C will not be dark.
How does a space suit on Mars work? Show me how it is pressurized, and how it is cooled
Why would you need spacesuit cooling on Mars? It's not space, where the side facing the sun heats up and it is difficult to radiate heat, there is an atmosphere that is quite chilly. I would think that you would need spacesuit heating on Mars, not cooling. However, I'm not a rocket scientist, is there anyone who has definitive knowledge on this topic?
At 6 millibar pressure, you are very close to a vacuum spacesuit environment; the atmosphere is not going to cool or heat you significantly*. Of course, the Sun is less intense on Mars, but if you are working and generating heat, I am sure you will need cooling.
* This is how the surface temperature in the Sun can be 25 C, while 1 meter up it's -25 C. If you were standing there, the heat from the surface would be much more important than the cooling from the atmosphere.
Our OS who art in CPU, UNIX be thy name. Thy programs run, thy syscalls done, In kernel as it is in user!
