hello space fans today's exciting news from the double-a s comes to us from the Sloan Digital Sky Survey which is a project that is being run at the Apache point observatory in sunspot New Mexico and in and specifically from this telescope here this is the 2.5 meter telescope and it is a survey telescope which means that it's a little bit different than other telescopes and for example Hubble or the Spitzer Space Telescope in the sense that with those telescopes the Hubble in one orbit might be looking at say a galaxy but in another war but it might be looking at Mars or something else and so where it looks varies very rapidly it doesn't look at the same region of sky very often this telescope is different it's designed to look at the same spot in the sky for a very very long time and this telescope the Sloan survey has been looking in the same region of the sky for since 1998 now you may ask yourself why would you want to do that why do you want to keep staring in the same area of sky for very long well in astronomy with ccd cameras and let me show you one here this is an old picture of the Sloan cameras and you can see all the CCDs lined up here with astronomy ccd cameras when you taken if you were to point it at the sky and let's say take a 100 second exposure you would see some stars and some galaxies and they're sure but they would be rather faint and if you did it again look at the same area of sky and did another 100 second exposure and then you took those two images and you carefully lined them up and then add them together what you will now see you have a 200 second exposure and you would see more fainter objects and you would have seen in either one of those individually now you may say well why don't you just take a 200 second exposure well the reason for that is that in these same see CDs if you just leave them open to collect light for a really really long time they start to get really grainy with with noise that builds up into the CCD itself so you want to minimize that so by you so ideally the idea is to take your the shortest possible exposure you can to keep down that noise and then add them all up it builds up a lot of signal and keeps the noise down here's about the best example I could find about here is a fuzzy fuzzy picture of Saturn which is an individual one but if you add it up say five or ten or even 100 pictures that same picture of Saturn you can get a much clearer much sharper image than you would if you had just taking one rather fuzzy one so if you add it up a bunch of shorter exposure images you would get a much clearer picture so that's why we do it so that's what this camera is currently doing so yesterday the the Sloan Digital Sky Survey announced their release of data released 8 that means that they have gone through eight full reprocessing of their data to include more images more area of the sky and and build up fainter and fainter to be able to see fainter and fainter objects and build up their catalogs more here's an example of where they look then this is where in the sky the Sloan Digital Sky Survey looks and as you can see they don't look in the entire area of the sky they're limited by the geography and and things like that so they don't look at the whole area now if you've been watching my videos for any length of time you've actually seen Sloan data before because here is a movie that was made back when data released for first came out and they made they made a three-dimensional movie based on all the objects catalog objects they found in there and as you can see there are big gaps in the data and is these gaps are due to areas where the Sloan cameras just can't see it's the part of the sky that they're just not imaging so that's why it has a sort of Walled appearance with big sheets of galaxies and things like this but it's really a wonderful extraordinarily striking a movie so I've included this in many different I think at least two of my videos already so yesterday they announced that they released this image and here is data release 8 so in the movie I showed you a data released for there were about a hundred thousand I'm sorry about what is it a four hundred thousand galaxies three hundred thousand stars maybe 45 thousand quasars that's about a million or so objects this is contains 500 million objects here I mean look at that this is the most comprehensive picture ever taken of the night sky ever and here you can if you if we zoom in a little bit closer we can see wrong way we can see that there we can see some of the fine grain structure in the in the image itself which has to do with these tendrils of galaxies that stretch throughout the cosmos this includes I think they said it includes hundreds of millions of galaxies this includes also stars and asteroids everything that the Sloan has seen half a billion object 500 million objects are in this image amazing to me this is an extremely important image and one that that it has no rival no one has ever built up an image of the night sky like this so I wanted to share this with you I hope you're getting something out of these these news reports and I really appreciate your positive feedback and making them keep looking up
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