12-18-2018, 06:14 PM
"This may be a dumb question but how come it was only discovered now? What has changed?"
These distant and small objects are extremely faint and can only really be detected by the largest telescopes and only if they happen to be pointing that way. Even when they might see a distant solar system object, it might not be obvious unless you are taking a very long exposure or are visiting the same piece of sky repeatedly and see a very dim object move over time - given the distance that movement will be tiny.
So it's hard to do, especially when the telescope is being used for several other projects.
These distant and small objects are extremely faint and can only really be detected by the largest telescopes and only if they happen to be pointing that way. Even when they might see a distant solar system object, it might not be obvious unless you are taking a very long exposure or are visiting the same piece of sky repeatedly and see a very dim object move over time - given the distance that movement will be tiny.
So it's hard to do, especially when the telescope is being used for several other projects.