Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Found In Space (On Flickr)

CmdrTaco posted more than 5 years ago | from the now-that's-clever dept.

Space 48

Jamie stumbled upon a writeup for all you astronomy and photography buffs out there (Perhaps my Dad or Uncle Jim are reading ;). From the writeup "The 'blind astrometry server' is a program which monitors the Astrometry group on Flickr, looking for new photos of the night sky. It then analyzes each photo, and from the unique star positions shown it figures out what part of the sky was photographed and what interesting planets, galaxies or nebulae are contained within. Not only does the photographer get a high-quality description of what's in their photo, but the main Astrometry.net project gets a new image to add to its storehouse of knowledge." Check out the Astrometry.net site for many cool pictures.

Sorry! There are no comments related to the filter you selected.

Astrometry.net and Comet Lulin (5, Interesting)

fyngyrz (762201) | more than 5 years ago | (#26923371)

I use them all the time; just shot comet Lulin [flickr.com] , they did a great job of exact location:

Re:Astrometry.net and Comet Lulin (2, Interesting)

Rei (128717) | more than 5 years ago | (#26925393)

I remember the first time that, just using a consumer-grade, non-DSLR camera (a Sony DSC-H2), I was able to image the Galilean moons. Blew me away. At first I thought I must have just captured bright background stars that just happened to be near Jupiter in the same plane, but I went back home and set my time and location in Celestia, it was a perfect match. I took more shots later and was able to see them changing positions around Jupiter appropriately.

It's amazing what you can do without any special equipment these days.

Re:Astrometry.net and Comet Lulin (2, Interesting)

fyngyrz (762201) | more than 5 years ago | (#26926247)

As far as I'm concerned with the current crop of DSLRs, we've entered a pretty darned fabulous era of shooting at night in general and the night sky in particular. It's getting to the point where they're trying to squish just the faintest remaining noise in the row/column amps and leakage from the sensels. It's already in the blinking amazing zone, but Canon seems to think they've got another full stop of noise reduction up their sleeve; all the online tech folk are doubtful, but me, I'll wait on the engineers, and will be ready to pony up for any such performance gain in the APS-C size sensors. Could already get it in an FF sensor, but Canon's not built the right balance of features to lure me there. Yet. :)

Find any killer asteroids yet? (4, Insightful)

heroine (1220) | more than 5 years ago | (#26923387)

It's only a matter of time before The Goog aggregates all pictures of the sky in realtime to find killer asteroids & make weather forecasts.

Re:Find any killer asteroids yet? (5, Funny)

0xdeadbeef (28836) | more than 5 years ago | (#26923491)

It will probably find evidence of vast machine intelligences like itself and decide not to tell us.

Re:Find any killer asteroids yet? (0)

Anonymous Coward | more than 5 years ago | (#26945273)

I believe what it found was a Vast Active Living Intelligence System [wikipedia.org] .

Re:Find any killer asteroids yet? (1)

Onaga (1369777) | more than 5 years ago | (#26924259)

-- Ads provided by Google --

Have you ever felt like your body was a mere vessel to help you in your journey? Do you like Kool-Aid? Maybe Heaven's Gate is right for you. Click here to find out more

Photosynth for the sky? (1)

i22y (10479) | more than 5 years ago | (#26923471)

Is this just Photosynth for the stars, finding common points and linking the images?

Re:Photosynth for the sky? (3, Interesting)

plover (150551) | more than 5 years ago | (#26923899)

It's similar to Photosynth in that it finds the stars in the sky, but it only provides location information. It does not provide links (you can't navigate from photo to photo the way you can in photosynth.) Not to say they couldn't add that functionality later.

I think of this more like a real-life version of the "Astrogator" role on the space ships from old sci-fi stories, where they arrive at some spot deep in space, the astrogator looks around at the stars and determines exactly where they are.

Lost in Space sequel? (1)

rts008 (812749) | more than 5 years ago | (#26925015)

I think of this more like a real-life version of the "Astrogator" role on the space ships from old sci-fi stories, where they arrive at some spot deep in space, the astrogator looks around at the stars and determines exactly where they are.

This is also the way I understood TFA.

Very cool, IMHO.

Re:Photosynth for the sky? (1)

mgblst (80109) | more than 5 years ago | (#26926071)

Very much like the astrogator, with one minor draw back. It only works from one position.

Re:Photosynth for the sky? (0)

Anonymous Coward | more than 5 years ago | (#26929059)

It's a logical next step to build a sighting telescope/targeting camera that can process where you are looking at in real time. There are wi-fi cards or the software/data could be loaded onto SD cards.

There are also tracking telescopes with automatic pointing as well. But this might tell you what is out there, so you can know what is out there to point at.

Re:Photosynth for the sky? (1)

Hadlock (143607) | more than 5 years ago | (#26925093)

I guess, in theory, if you work from a single reference image that you know the exact date and time, and proportions (for measuring shadows) you could create a 3D world that was made from a mesh of user's photos. As long as you have the date and time (within a minute or two) and your image was connected to another image that was ultimately connected to the reference image (for scale) you should be able to calculate your lat and longitude based on shadows, knowing where the sun is in relation to the earth at that point in time. Kind of like finding your lat and long. using the stars and a clock, but with shadows.

Awesome (2, Interesting)

mc1138 (718275) | more than 5 years ago | (#26923485)

Seriously, this is a really cool use of technology at work, keeping the spread of information flowing. I wonder if they'll be able to figure out where I live though...

Re:Awesome (2, Insightful)

zappepcs (820751) | more than 5 years ago | (#26923707)

May I also posit that it not only keeps the spread of information flowing, but increases both the available information to each of us and the aggregate total information available to mankind.

Small changes like this change how we see life in the long term. Seeing the sky as if it were so many maps of a foreign country brings with it familiarity that raises awareness and new thinking.

This, and projects like it, are awesome. Spell that with capital letters and boatloads of enthusiasm.

Re:Awesome (2, Funny)

rolandog (834340) | more than 5 years ago | (#26923825)

<boatload of="enthusiasm" style="text-transform: uppercase;">That. T-H-A-T. That.</boatload>

Re:Awesome (1)

zappepcs (820751) | more than 5 years ago | (#26923889)

ROFL... ok, spell awesome with capital letters and boatloads of enthusiasm

Re:Awesome (2, Funny)

plover (150551) | more than 5 years ago | (#26923979)

I wonder if they'll be able to figure out where I live though...

Given that they're matching these pictures against those taken over the last 60 years or so, and considering the accuracy of the typical consumer camera, I think they'd be able to pinpoint you to an orbit somewhere around the star Sol.

Typical editing (-1, Offtopic)

Gothmolly (148874) | more than 5 years ago | (#26923513)

Taco, nobody cares about your douchebag relatives.

Very cool, but np-complete? (1)

nganju (821034) | more than 5 years ago | (#26923517)

This is great stuff, but I wonder how the algorithm works. Any Computer Science wizards on here know how this picture identification could be done in less than polynomial time?

Re:Very cool, but np-complete? (1)

corsec67 (627446) | more than 5 years ago | (#26923563)

The "interesting points" are obvious: dots on the picture. You take the brightest ones, and then search for the pattern generated by those dots in your database.

Astronomy actually seems like one of the easiest applications of this kind of thing.

Re:Very cool, but np-complete? (2, Interesting)

jamie (78724) | more than 5 years ago | (#26923583)

There's a PDF link buried in the interview [nyu.edu] which had me giggling with geekish delight. The phrase

"hash codes" for locations on the sky

makes me happy.

Also, I'll give credit to waxy.org [waxy.org] which is where I read this first.

Re:Very cool, but np-complete? (3, Interesting)

kramer2718 (598033) | more than 5 years ago | (#26923603)

If it is done in polynomial time, then it would by definition be in P which means it would NOT be NP complete unless P=NP.

I think you are trying to ask how it could be done in less than exponential time (which is how fast the fastest algorithms to solve NP complete problems run).

I personally would expect an algorithm to perform the match would run in O(U*US+K*KS+UI*KI*U) where U=the number of unknown (ie flickr pictures), K=the number of known pictures, US=the average size of an unknown picture, K=the size of the average known picture, UI=the number of interesting things in an unknown picture and KI=the number of interesting things in a known picture. However, it would often run faster because it should be fairly easy to disqualify two pictures as containing any of the same interesting features.

Re:Very cool, but np-complete? (1)

buchner.johannes (1139593) | more than 5 years ago | (#26924723)

If it is done in polynomial time, then it would by definition be in P which means it would NOT be NP complete unless P=NP.

No, the N means it can only be calculated on a nondeterministic (Turing) machine in polynomial time. Common mistake.

Re:Very cool, but np-complete? (1)

IWannaBeAnAC (653701) | more than 5 years ago | (#26925929)

Did the GP actually make a mistake though? P is a subset of NP, but the GP referred to NP _complete_, which is an equivalence class and is not, in any sense, a superset of P (unless P=NP).

Re:Very cool, but np-complete? (1)

buchner.johannes (1139593) | more than 5 years ago | (#26927537)

Question is, is GP also a superset of NP ...

Re:Very cool, but np-complete? (0)

Anonymous Coward | more than 5 years ago | (#26926409)

did you not actually read what he fucking said? or could you just not resist jumping in with your irrelevant "correction" anyway?

Re:Very cool, but np-complete? (0)

Anonymous Coward | more than 5 years ago | (#26923755)

Maybe if they included some type of reference for their work? Maybe some type of bibliography [astrometry.net] on their web page..

Re:Very cool, but np-complete? (5, Informative)

drom (26464) | more than 5 years ago | (#26924419)

You can think of our search as randomly trying millions of possibilities and hoping for the best. The reason it's so fast is that we order the random attempts very cleverly and tend to find the answer fast if it is indeed solvable. The algorithm usually terminates because it finds a match or times out; rarely does it exhaust the search space in time. The actual complexity of our system is roughly O(N choose 4) where N is the number of stars in the image. Interestingly, this is polynomial, roughly O(N^4), though probably closer to O(N^5) once verification is added.

In summary: the astrometry problem is not NP-hard when approached like we do.

Disclaimer: I am one of the astrometry.net contributors.

Re:Very cool, but np-complete? (1)

Leafheart (1120885) | more than 5 years ago | (#26928383)

Drom, very interesting post. it seems to me that you guys are using some kind of heuristic to solve the problem. Which I find amazing. Can you delve a bit on it, or would it be too problematic? I got really curious about the heuristic you guys are using.

Re:Very cool, but np-complete? (2, Informative)

Nyeerrmm (940927) | more than 5 years ago | (#26924501)

I'm guessing its basically just a star-tracker algorithm. I've taken a class on it, but its probably the thing I understand and remember least since I've been in grad school. Basically, they pick out the bright stars, and measure their locations to sub-pixel precision through centroiding, so you're working on a set of coordinates, not an actual image.

Then an algorithm cycles through a star catalog to compare the relative positions and identify the stars. In this case, since the angular size of a pixel is unknown; this has to be figured in as an unknown as well. Unfortunately I can't say how that works, I do know one guy who did his dissertation on a new search algorithm that reduced the computational cost by an order of magnitude.

Really, if you're interested, do a literature search on star tracker technology.

Re:Very cool, but np-complete? (1)

buchner.johannes (1139593) | more than 5 years ago | (#26924813)

It probably can be shown to be equivalent to the Clique problem.

Maybe some approximating could do the task in P too, but that doesn't say anything about the constants in your Landau-estimation. Your NP algorithm may be way faster than your P algorithm ...

The illuminated. (1)

Ostracus (1354233) | more than 5 years ago | (#26923539)

"Not only does the photographer get a high-quality description of what's in their photo, but the main Astrometry.net project gets a new image to add to its storehouse of knowledge."

Dear Astronomy Buff. You have an excellent picture of a cruising UFO.

sounds like a good time (3, Funny)

bugs2squash (1132591) | more than 5 years ago | (#26923813)

to confuse the shit out of someone with photo of a backlit piece of black card with random pinpricks in it.

Re:sounds like a good time (5, Funny)

plover (150551) | more than 5 years ago | (#26923921)

to confuse the shit out of someone with photo of a backlit piece of black card with random pinpricks in it.

Sounds like something a random prick would do.

Re:sounds like a good time (0)

Anonymous Coward | more than 5 years ago | (#26925125)

cue /b/

Re:sounds like a good time (1)

Xest (935314) | more than 5 years ago | (#26927083)

To be fair it raises a point though- if the system uses this data automatically then can it tell the difference to say an image from a screenshot of a game like Eve online? I'm not sure what the data they're receiving is actually used for.

What if a user has a rendered image on their system that they downloaded as a background or something and uploads it believing it's a real image?

Re:sounds like a good time (1)

plover (150551) | more than 5 years ago | (#26927679)

They already have an independent catalog of star data (the USNO-B) from which they built their reference search data. It's used to locate the incoming pictures, and they won't extend the catalog from user-submitted pictures.

However, since they're talking about using the data to locate faint moving objects, it would be theoretically possible to submit a series of doctored photos that show a fake "object" moving.

Even this would be pretty much useless because if you faked anything of interest, such as an asteroid plummeting toward Earth, dozens of astronomers would be scanning the skies looking for a glimpse of it. In astronomy, it's easy to confirm data. So they'd call shenanigans on you when they didn't find it, and you'd be kicked out of the club.

Re:sounds like a good time (0)

Anonymous Coward | more than 5 years ago | (#26925439)

In the article he mentions that people tried this. They submitted hand-drawn images and one iPhone screenshot of night-sky app.

Correction (1, Insightful)

Anonymous Coward | more than 5 years ago | (#26923849)

Check out the Astrometry.net site for 4 cool pictures.

Am I missing something on the gallery page?

conspiracy (1)

binaryseraph (955557) | more than 5 years ago | (#26924295)

Its just a conspiracy to spy on Russian space ;)

Moar DATA (1)

Anti_Climax (447121) | more than 5 years ago | (#26924695)

This will get even better once Pan-STARRS [wikipedia.org] and LSST [wikipedia.org] get up and running

Whoo would have known? (4, Insightful)

fava (513118) | more than 5 years ago | (#26924995)

When these kinds of services (meaning flicker et al) open up their api to public use there are always some who cant figure out why.

Well folks, this is the reason why.

I betting when the executives at flicker sat down to decide if they were going top open up the api, they had no idea that someone would use it to create a map of the sky.

Re:Whoo would have known? (1, Funny)

Anonymous Coward | more than 5 years ago | (#26925583)

Whoa, that rhymed.

Major Discovery (2, Funny)

aoheno (645574) | more than 5 years ago | (#26925897)

My infrared image of the kitchen floor bacteria is being interpreted as a major new galactic cluster with supermassive black hole.

Article summary raises interesting questions. (1)

CornMaster (1105789) | more than 5 years ago | (#26927667)

Like how do you properly post an emoticon in () text? http://xkcd.com/541/ [xkcd.com]

Re:Article summary raises interesting questions. (2, Interesting)

drinkypoo (153816) | more than 5 years ago | (#26928345)

Use a different font. Slashdot makes available the <tt> tag which works nicely - emoticons often look better in monospace text anyway. I suppose that's probably subjective though; I grew up with monospace text, if you didn't you probably feel the other way. I think we can all agree that people who use the tag and the enter key to format their text as if they were old school are extremely fucking annoying, though.

WOW! (1)

certain death (947081) | more than 5 years ago | (#26928065)

That is truly badass! I love it when smart people do things like this!
Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?