We have discussed two basic techniques for determining the age of a planetary surface: studying the abundance of impact craters and radiometric dating of surface rocks. (a) Which technique seems more reliable? Which technique is more practical? Explain.

Radiometric dating

Explanation: Radiometric dating is a precise method of determining the age of archeological artifacts and rocks, it usually makes use of certain radio isotopes of Uranium-235,Rubidiun-87 etc.

Radiometric dating which is also known as radioactive dating is carried out by comparing the naturally occurring radioactive materials of the artifact or rock under study to product of its decay process.

Craters dating is a random process so its reliability can not be guaranteed.

a. Radiometric dating

b. Crater counting

Explanation:

a. Radioactive rock dating is more reliable than measuring crater abundance because its precision is higher moreover the time early bombardment ended is not well known so makes crater counting misleading and crater counting can be easily affected by movement of surfaces which can easily modify or erase preexisting craters.

b. Crater abundance are easier measure on the planet which makes it more practical compared to radiometric because it is less expensive in the sense that it is cheaper to take photographs of craters for analysis than to land on surfaces of planetary bodies to take samples of rock for radioactive dating.