Trash can be accidentally or intentionally jettisoned by EVA astronauts working on a manned space station. Trash can orbit in close proximity to the parent vehicle for the short term. Some satellites create clouds of chemicals, which can be viewed by the naked eye at high altitudes as black and white or colorful displays. Launches of rockets can often be viewed in the night sky from U.S. east or west coast locations, and they can create cloud-like formations that are really unique to observe and photograph. Other launches have had unexpected displays from fuel venting or motor firings that have caused reports of unidentified flying objects in e.g. Russia and South America.
Geostationary satellites form a belt around the celestial equator.
A number of spacecraft orbits are affected by gravitational harmonics. Their positions are studied over time to ascertain information about the earth's gravitational field. Observers can make measurements on the positions of these objects to assist in such endeavors. Amateur satellite watchers have been able to observe these flybys using telescopes or CCD cameras. In at least one case NEAR was reportedly visible to the unaided eye.