The ocean constantly moves. As a result of this, it is responsible for transporting many things held within its waters. Transport of heat and water means the oceans have profound influences on our weather and climate. It also transports things that can be hazardous for humans (such as icebergs), and damaging to the marine environment (such as pollution, including oil spills and plastics).
We cannot routinely observe all the pollution in the oceans from space, or get satellite data from the future to know where these things will be transported. However, we can use information derived from in situ data, satellites and models to understand ocean currents and predict where pollution such as plastic is transported and will aggregate.
We also use satellites to receive and transmit information from buoys that float around the ocean, providing vital data for ground truthing satellites, and further understanding our oceans.
You can use the interactive animation at www.adrift.org.au to see how scientists have used information from these buoys to learn how the ocean moves and show where plastic waste (or other pollutants) in the ocean might end up.
You can also follow Dr Erik van Sebille (creator of Adrift) on twitter - @ErikvanSebille to learn more.