A new study revealed that NASA’s transit exoplanetary surveillance satellite (TESS) is able to detect the mysterious “ninth planet” and may even have already noticed it, scientists just need to “sift through” the data to reveal it.
In the case of Planet Nine, it would be impossible to detect its passage, because it would not pass between Tess and the sun. And a single exposure would not reveal such a weak object as Planet Nine.
However, the way Tess looks at parts of the sky for a long time can be combined with an astronomical method called digital tracking.
If you stack these images, faint objects can become much brighter, revealing objects that would otherwise be hidden.