Final answer:
Space scientists and earth scientists often use a ruler for small measurements in both customary and metric units, while tape measures are used for longer distances. Scientific notation is employed by space scientists for extremely large distances.
Step-by-step explanation:
The tool commonly used by both space scientists and earth scientists for measuring small objects and distances is the ruler. Rulers can display measurements in both customary units such as inches, and metric units including millimeters and centimeters.
In the realm of space science, rulers may be used for creating models or maps, whereas earth scientists might use them to measure geological samples or create accurate maps of the Earth.
When dealing with larger distances or flexible measures, such as the length of a room or a large object, the preferred tool is a tape measure, which can extend much longer than a ruler and provides both customary and metric unit measurements.
For extremely vast distances, such as those in astronomy, scientists often use scientific notation to express measurements, underscoring the immense scale space scientists work with as compared to earth scientists.