UFO Streaks Through Martian sky 440
lkatz writes "The BBC is reporting that the Spirit rover has observed an object streaking across the Martian sky. They believe it was either a meteor or possibly the Viking 2 probe which still orbits Mars."
Meteor? (Score:3, Interesting)
Blogzine.net [blogzine.net]
Re:Misleading title (Score:5, Interesting)
LGM (Score:3, Interesting)
Seriously though, at the very least, the cool thing is that we have seen a "shooting star" from the surface of another planet for the first time. The timing of NASA and JPL on both Spirit and Opportunity so far has been impeccable. Let's hope their luck continues.
Beagle 2 (Score:2, Interesting)
Atmospheric phenomenon? (Score:-1, Interesting)
It's hypothetically possible that such an event could create false imagery on the Rover, which is hardly high-res photography to begin with and then sent back to us over a noisy channel (space).
Re:Or perhaps... (Score:3, Interesting)
Let me get this straight... (Score:5, Interesting)
I'm so confused!...
Offtopic - Dyson sphere (Score:5, Interesting)
believing in what sense? That one had been observed? I don't think so.
That it could be built? You'll need nearly Jupiter's mass of a substance with the same tensile strength as an atomic nucleus. In sort, not known to our physical theories (I'll stop just short of saying it's impossible). And then to spin the thing up to 1 gravity, you'll need the amount of energy that our sun puts out in 1000 years. In short, extremely difficult. Even then it's unstable.
His concept of the "Dyson Sphere" was very different from the SF concept of "a solid shell around the sun". He merely observed that the end-point of putting stuff in space to soak up the sunlight, is that all the sunlight is soaked up by millions upon millions of things, and all that gets out is the waste heat.
More info here [everything2.com]
Ghost ship (Score:3, Interesting)
The thing about real ghost ships, and abandoned cars, etc., is that they either sink or rust or are towed away in the end. Interplanetary space probes generally do not.
Re:Meteor? (Score:5, Interesting)
joke? immanuel velikovsky [knowledge.co.uk] has made himself quite a reputation positing such events. calling himself a "scientist" he's claimed that venus was "ejected" from jupiter 3500 or so years ago whereupon it cruised around the solar system with a whole bunch of near misses of larger bodies before settling into its current orbit.
the majority of his "proof" for all this are biblical stories about astrological events. for instance, velikovsky posits that the friction of venus passing closeby earth raised the surface temperature of this planet " sufficient to make the vermin of the earth propagate at a very feverish rate" thus resulting in the plagues in exodus. that's just a sample.
wildly improbable to say the least - but velikovsky has managed to sell millions of books to the heroically undereducated public flogging this theory. a nutbar... but a rich nutbar.
right. sensical talk about velikovsky can be had here [skepdic.com].
Re:Meteor? (Score:5, Interesting)
Since the speed of light is approximately 670,616,629 mph, a mere 3,500,000 mph seems quite stately in comparison. (although still a nice percentage of c)
A way to check for repeated sighted (Score:5, Interesting)
Although orbital mechanics is not my specialty, I think NASA should be able to calculate an approximate orbit and take more images to see if it might be Viking 2.
The height of the streak in the image, the distance away and the orientation of camera will give the position. Put this with velocity to get the orbit. So, we just need to know distance away and velocity. The length of the streak plus the exposure time can give them a equation of velocity vs. distance away. Orbital mechanics gives another equation for velocity vs. height. Use these 2 equations to solve for the orbit, assuming the object is in orbit and not just passing by. NASA knows the orbital elements of Viking 2 when it was in use and can use these to see if the calculated orbit is reasonable.
Then using the orbit, calculate times the object would be visible to either rover and make some long exposures at the predicted times to look for it again. The only problem I can see is that the measurement error might be too much to make accurate predictions about future approaches.
This assumes NASA cares whether it's Viking 2.
Re:Offtopic - Dyson sphere (Score:2, Interesting)
Astronomical odds? (Score:5, Interesting)
The odds against this kind of coincidence must be staggering. Any math geniuses want to take a stab at it? We could estimate how often the half-dozen (?) satellites around mars would pass through that particular section of the sky, and we know roughly how many photos the rovers take in a given day... The odds must be something like one in a billion, or worse. I can't help but think of the slashdot sig I see once in a while... something like "The face of the moon is covered with the results of astronomical odds."
Re:Offtopic - Dyson sphere (Score:3, Interesting)
Larry Niven was talking about the fact that he orginally had no plans to go back to ringworld, but the amazing amount of interest that his story had generated had made it very palitable to him. (I would love to see a recording of the MIT students chanting "the ringworld is unstable" in the halls)
Either way, when Freeman Dyson says something along the lines of "Hmmmm, I like it, but why not do build a lot of little ones instead?" it certainly would get a pen in my hand.
Re:Offtopic - Dyson sphere (Score:3, Interesting)
Hmm, that all seems to depend on the size of the sun. What if you build your ring around a white dwarf? Since it's not technically in orbit around the sun, the size of your ring is only determined by the distance the surface needs to be from the sun to get earthlike sunlight, which is determined both by the size and type of the sun. A small sun means a small ring. Also, you'd need less spin to get 1g for a smaller ring.
I'd like to see someone do the math for the smallest stars we know.
Re:Meteor? (Score:2, Interesting)
I make a basically content-free but technical post, and it gets rated up. When I post something with a point (but no impressive numbers), it just gets ignored. Ahh, the vagaries of / moderation.
Re:Astronomical odds? (Score:2, Interesting)
Is it conceivable that NASA knew enough about the Vikings' last-reported position and orbital decay to predict this? Sorry, thats got to be less likely - they'd have crowed about it for a start.
Re:Velikovsky serves a purpose... (Score:3, Interesting)
but... how are the laser reflectors evidence for manned landings? Couldn't they have been placed by a robot?