Samples from other worlds provide some key information on planetary evolution and history but are they the only way to obtain such knowledge?
A Soviet Luna spacecraft lifts off from the Moon after collecting a drill sample for return to Earth.
Samples are currently making news for NASA’s planetary exploration program. Last August, the rover Curiosity, equipped with a package of laboratory instruments, landed on Mars. On February 9th the rover’s robotic arm drilled its first hole in a rock selected by scientists. In their attempt to gain more information about Mars, scientists will use the rover’s science package to remotely analyze these samples on the martian surface. The results will give them some fairly detailed knowledge on the chemical and mineral make up of these rocks. But what else can we possibly learn from samples?
Geologists in general and planetary scientists in particular often emphasize that “such and such” cannot be known for certain “until we obtain samples” of some planetary surface or outcrop. What is this obsession with samples? Why do (some) scientists value them so highly and exactly what do they tell us? Answers to this question (for there is not a single, simple one) are more ...