Asteroid Zoo Talk

Known Asteroids - Why not seeing them can be a good thing

  • CTidwell3 by CTidwell3

    I have noticed that sometimes the examples of known asteroids can't be seen, and it reminded me of a similar question that use to come up all the time in the Planet Hunters Zooniverse project. In that project, simulated examples of planets had been added to the images being reviewed and some of those example could not be detected. There was the then the common question that would pop up of "This is unrealistic" or "No one could possible be expected to see this". The answer was "Yes, that is right. We add these sets so that we can confirm that a planet detection of this sort is not feasible by this project. We know the data set shows a planet and the fact that no one records seeing it helps confirm what can and cannot be seen".

    The same thing can be said for this project. When a set of frames is in a known location of the sky at a known time, that location/time can be run up against a database of known asteroids. If one is located within the image, it can be marked on the images as definitively being in a certain location within the image. Not being able to see that helps determine the types of asteroids that can and cannot be found in these sets of images.

    This means that if you get a notification that a known asteroid is in an image and you did not mark it, two things can be going on. First, you might not have seen it and reviewing where it was suppose to be can help you see it. I know I have missed a few and when reviewing it I am then able to see it and have another example of the type of thing to look for. If I cannot see anything there, then the second thing has happened... I know I have provided another data point for this project confirming that asteroids of the type in that set are not visible in the data set.

    Here is another way of illustrating this. Can you see anything "Surprising" here on google maps:

    https://www.google.com/maps/@33.7971636,-112.8449965,8z

    If you didn't see it in that link, it really is there. Try this link:
    https://www.google.com/maps/place/Surprise,+AZ/@33.7971636,-112.8449965,8z/data=!4m2!3m1!1s0x872b50449c4f72a3:0x3d108204ce52db2

    Still don't see anything "Surprising" there? Its because there is not enough detail. Zoomed in a bit more, you can see:
    https://www.google.com/maps/place/Surprise,+AZ/@33.7012474,-112.4474288,11z/data=!4m2!3m1!1s0x872b50449c4f72a3:0x3d108204ce52db2

    It not the perfect analogy, but it sorta what is happening in some data sets. If the image is overpowered by bright stars, or the seeing was not optimal when the set was taken, an asteroid that is definitely in a particular area of an image cannot be seen even if you know where it is.

    Posted

  • stonepenny by stonepenny

    thank you. I've mostly missed the known ones where the frame was so over exposed, the picture was white/gray, with some whiter blobs. 😃

    Posted

  • Dr.Asteroid by Dr.Asteroid scientist, admin in response to CTidwell3's comment.

    Thanks for the explanation - yes. There is also chance that a known asteroid - a very well known one is the frame but that particular image just is a little less sensitive than predicted. (a light cloud came in - some other little change) which pushes the known asteroid below the threshold of the detector.

    Posted