For the first time in human history we know of planets around other stars and many of those other planetary systems look quite different from our own. Many have a planet like Jupiter, or even bigger, nearest to the sun. If we are to understand why this is the case, and how likely it is that there are Earth-like planets elsewhere, we need to better understand how planets form.
You are here
Microbial life forms have been discovered on Earth that can survive and even thrive at extremes of high and low temperature and pressure, and in conditions of acidity, salinity, alkalinity, and concentrations of heavy metals that would have been regarded as lethal just a few years ago. These discoveries include the wide diversity of life near sea–floor hydrothermal vent systems, where some organisms live essentially on chemical energy in the absence of sunlight. Similar environments may be present elsewhere in the solar system.
The small bodies in the solar system include comets, asteroids, the objects in the Kuiper Belt and the Oort cloud, small planetary satellites, Triton, Pluto, Charon, and interplanetary dust. As some of these objects are believed to be minimally altered from their state in the young solar nebula from which the planets formed, they may provide insight into planet Earth and the formation and evolution of the solar system.
NASA’s Planetary Science missions to the outer planets help reveal secrets about the solar system by observing those outer distant worlds up close. Jupiter’s moon Europa and Saturn’s moon Enceladus are now thought to hide liquid water beneath their frozen surfaces and are high priority targets for NASA. Unlocking their secrets and those of the outer planets will help scientists understand more about planet Earth and the formation and evolution of the solar system.
Planetary Science missions, past, current, in planning or in development, extend mankind’s presence to the solar system’s inner rocky worlds, helping to unlock the secrets of the solar systems’ composition, history and evolution, and how life established itself on Earth.
Understanding the planets and small bodies that inhabit our solar system help scientists answer questions about its formation, how it reached its current diverse state, how life evolved on Earth and possibly elsewhere in the solar system, and what characteristics of the solar system lead to the origins of life.
The Regional Planetary Image Facilities are an international system of planetary image libraries, established in 1977. They maintain photographic and digital data as well as mission documentation and cartographic data. Each facility's general holding contains images and maps of planets and their satellites taken by solar system exploration spacecraft.