However, where changing conditions are an issue such as near river or sewage discharges, close to the effects of volcanism or close to areas of freshwater input from melting ice, a grab sample can only give a very partial answer when taken on its own.
22.
Venus has over 9 / 10ths Earth gravity, and a thick atmosphere to blast through, but no human would want to land there, so it's not an issue, unless we want a robotic probe to grab samples and return with them . talk ) 07 : 47, 6 December 2012 ( UTC)
