 To track litter in the ocean, scientists are now using a bird's eye view, or better yet, an astronaut's view, as Tracy Wolf tells us. Ocean trash is such a big problem that scientists have now designed a new sensor to track marine litter from space. Trash in the ocean is any human-made item that ends up in water, and 80% of it is made of plastic. Scientists are now able to use a space satellite to detect hot spots.