probes

A probe is an instrument used to explore, measure, or sample a system. Probes come in many forms and are used across science, engineering, and medicine. They typically sense physical quantities such as temperature, pressure, chemical composition, or electrical signals and relay data to a recorder or control system. In common usage, the term covers both small laboratory sensing tips and large exploratory spacecraft.

In space exploration, a probe refers to an unmanned spacecraft designed to observe distant objects, measure properties, or collect samples. Probes may fly past targets, enter orbit, land, or impact the surface. They carry instruments for imaging, spectroscopy, magnetometry, and environmental measurements. Notable examples include the Voyager missions to the outer planets, Cassini–Huygens to Saturn, New Horizons to Pluto, and various Mars orbiters and landers.

In medicine, a probe is a slender instrument used for examination or to guide other tools. Examples include ultrasound probes for imaging, catheter probes for sensing inside vessels, and biopsy probes for sampling tissue. In laboratory science, probes can be sensors attached to cables or integrated into microdevices to monitor chemical concentrations, pH, or DNA signals. Electrical engineers use probes such as oscilloscope probes or logic probes to test circuits.

Probes are designed for reliability and accuracy. They may be passive or active, require calibration, and may include insulation, shielding, or coatings to withstand harsh environments. Data from probes are typically processed by onboard computers or transmitted to ground stations, and interpreted to support decisions or scientific analysis.