A "Lander" is a type of spacecraft designed to land on the surface of a celestial body, such as a planet or moon. Its primary purpose is to conduct scientific research and gather data about the environment, geology, and atmosphere of the target location. Landers are equipped with various instruments, cameras, and tools to analyze soil samples and take measurements. One of the most famous landers is the Mars Pathfinder, which successfully landed on Mars in 1997. It carried the Sojourner rover, allowing scientists to explore the Martian surface. Other notable landers include the Viking missions and the Phoenix Mars Lander, each contributing valuable information about their respective destinations.