Planetary geologists answer questions about the solar system's evolution by investigating properties of other planets' surfaces and interiors. Planetary geology is a varied field that encompasses many subdisciplines and research methods, each of which informs the others. Careers in this field generally require a doctorate.

The main employers for planetary geologists are academia and government, although a few private research institutions also exist. In universities, planetary geologists can have careers as professors or research scientists. Both of these career paths require a doctorate in geology, geophysics or a related field like physics, astronomy, engineering or chemistry. However, those with related undergraduate degrees can seek internships in either sector as a stepping stone to further study, and those with master's degrees in related sciences sometimes work as technicians, carrying out tasks related to their supervisor's research.

Perhaps the best-known job function of planetary geologists is remote sensing, or gathering information from places other than the Earth by using specialized tools. The Mars rover Curiosity is a famous example of remote sensing equipment, gathering data about the planet's mineralogy, chemistry, atmosphere and other environmental properties using tools such as:

• cameras
  
• spectrometry
  
• chromatography
  
• imaging software

Telescopes are another kind of remote sensing equipment. Planetary scientists from many background specialties collaborate to design such complex equipment.

The experiments that planetary geologists perform can simulate processes within a planet, on the planet's surface or in its atmosphere. A strong background in physics, chemistry, engineering and geosciences is crucial for planetary geologists to design these experiments. Specialized training in different methods for materials characterization may also be necessary. Technicians with master's degrees or doctorates, as well as interns with undergraduate degrees, can assist primary investigators and graduate students as they carry out these experiments.

Some planetary geologists use data that they or others have gathered to create computer simulations of planetary formation and evolution. These modelers need to have a firm grasp of math and physics, as well as programming knowledge. Based on the models that these planetary geologists create, other planetary geologists design experiments and design remote sensing equipment, and these models are also used to capture the public imagination to garner support for further exploratory efforts.