While this may sound silly (NASA detects life of earth!) it is actually a nontrivial feat to detect the presence of life on a planet if you are sufficiently far

While this may sound silly (NASA detects life of earth!) it is actually a nontrivial feat to detect the presence of life on a planet if you are sufficiently far away from it. So the fact that they were able to detect signs of life from about as far away as the moon is an interesting datapoint for the sensitivity of the instruments on board. This is the kind of calibration you should do if you want to study other planets.