This made me smile. Nice news !
Me too, it's good to know that Philae hadn't bounced off into space.
RTFA. It was already known it had landed, just not exactly where.
Philae Found
31–40 of 135 posts
Re: Philae Found
#32Earlier quoted context omitted.
IIRC, the designers had little idea what kind of surface the comet would have. Could be ice, could be rocks, could be dust. What kind of landing gear + fixation gear would have been better?
INANE (I Am Not A NASA Engineer), but perhaps 4 or better yet more legs arranged in a tetrahedron or analogous polyhedron would better ensure the lander did not get stuck inside a crevasse; an inner rotating body could then bring the lander into a working position. The more the legs, the higher the chance the lander could 'roll' to a lower ground when initially bouncing off the surface, but the optimal number of legs…
How much mass would another leg have? Which scientific instrument with that mass would you suggest to eliminate for that extra leg?
Re: Philae Found
#33Off-topic, but why do they usually shoot black and white? Is it something to do with the file size?
Re: Philae Found
#34Off-topic, but why do they usually shoot black and white? Is it something to do with the file size?
They probably shot it in several spectra and this is their highest resolution one. It might not even be visible light.
Re: Philae Found
#35"At 2.7 km, the resolution of the OSIRIS narrow-angle camera is about 5 cm/pixel, sufficient to reveal characteristic features of Philae’s 1 m-sized body and its legs, as seen in these definitive pictures." I looked at the pictures and the human eye can barely see the lander. Considering that the chances of losing these landers is not that low, I don't understand why they don't make them visually more distinctive. An…
> I looked at the pictures and the human eye can barely see the lander. Considering that the chances of losing these landers is not that low, I don't understand why they don't make them visually more distinctive. If it was hot pink it would have made no difference, it ended up in a bad spot with limited solar power.
Finding the lander made a difference. Now they can put the the data into context (“[...] we now have the missing ‘ground-truth’ information needed to put Philae’s three days of science into proper context [...].”).
ESA is lucky it had a high-resolution camera to distinguish the lander from the terrain. If you only have low-res cameras, it might be useful to have a visually distinguished lander so you find it despite of poor resolution (1 bright pixel).
A naive solution might be to make future landers reflect a certain wavelength and use a tiny camera that is tuned to capture that wavelength. Finding the lander should be much easier then.
Re: Philae Found
#36Off-topic, but why do they usually shoot black and white? Is it something to do with the file size?
Not sure how accurate it is, but an article found via cursory Googling[0] makes it seem like a true-color photo doesn't have as much scientific value as other spectrum recording photography - different filters over the monochrome camera can make it easier to see heat, minerals, radiation, etc.
Goes on to mention producing a true-color photo is kind of a pain in the ass for these probes.
0. http://www.straightdope.com/columns/read/3088/why-are-images...
Re: Philae Found
#37Off-topic, but why do they usually shoot black and white? Is it something to do with the file size?
Also the picture may not be "black" and "white", it's just captured at a single frequency [or a small spectrum], and readings are for that particular frequency.
Combine multiple spectrum and you get a color image.(Though comets don't have too much change across the spectrum.)
Re: Philae Found
#38Off-topic, but why do they usually shoot black and white? Is it something to do with the file size?
it's not worth it scientifically to use a bayer filter. if there's a color shot, it's usually false color or three successive shots with a R/G/B filter separately. this spacecraft may not have such filters available as the comet is expected to be about as colorful as a lump of coal.
Re: Philae Found
#39Earlier quoted context omitted.
> I looked at the pictures and the human eye can barely see the lander. Considering that the chances of losing these landers is not that low, I don't understand why they don't make them visually more distinctive. If it was hot pink it would have made no difference, it ended up in a bad spot with limited solar power.
Finding the lander made a difference. Now they can put the the data into context (“[...] we now have the missing ‘ground-truth’ information needed to put Philae’s three days of science into proper context [...].”). ESA is lucky it had a high-resolution camera to distinguish the lander from the terrain. If you only have low-res cameras, it might be useful to have a visually distinguished lander so you find it despite…
But then you probably have a camera that has exactly one use – finding the lander – which doesn't necessarily yield the same quality of scientific results than having a camera that is more useful to the actual goals of the mission. Yes, finding Philae is nice, but not finding it wouldn't have been that bad, and the camera surely generated worthwhile data even without finding Philae.
Re: Philae Found
#40Earlier quoted context omitted.
> I looked at the pictures and the human eye can barely see the lander. Considering that the chances of losing these landers is not that low, I don't understand why they don't make them visually more distinctive. If it was hot pink it would have made no difference, it ended up in a bad spot with limited solar power.
Finding the lander made a difference. Now they can put the the data into context (“[...] we now have the missing ‘ground-truth’ information needed to put Philae’s three days of science into proper context [...].”). ESA is lucky it had a high-resolution camera to distinguish the lander from the terrain. If you only have low-res cameras, it might be useful to have a visually distinguished lander so you find it despite…
> A naive solution might be to make future landers reflect a certain wavelength and use a tiny camera that is tuned to capture that wavelength. Finding the lander should be much easier then.
That's a complicated way of saying "paint it like barricade tape", isn't it?