To planetary scientists, astronomers and astrophysicists, Earth is but one of several known worlds that host a substantial atmosphere and corresponding climate. By comparing these worlds, researchers can gain insights to their atmospheric compositions, current climatic states, and possible evolutionary histories. Through these comparisons, we have learned that warming by greenhouse gases can play a key role in determining a planet or moon’s average temperature at its surface.
Over the past 50 years, robotic probes have visited every terrestrial planet, the largest asteroids, Jupiter, Saturn, Uranus, Neptune, and now Pluto – one of several dwarf planets, or “Plutoids” that inhabit the Kuiper Belt of icy objects. For New Horizons, this has been a 9 year 3 billion mile journey. Next for the grand-piano-size spacecraft are other objects in the Kuiper Belt and beyond.