be one of the last as the plutonium to thirty eight become scarce joining me to discuss it is andrew chaikin science journalist and space historian anderson i said oh he's also excuse me the author of a man on the moon and a passion for mars almost left your books out there is our andrew thanks for coming back on the show tonight you know some people are saying that this is the most ambitious rover ambitious a mission to mars yet what do you say about it yeah i mean that pretty much sums it up i mean the previous two routers that were spectacular in their own. were about the size of a golf cart and this one is about as big as an s.u.v. and it's just as you as your graphic showed it's full of an mazing instruments in fact it has so many instruments that it's carrying two. mars are things that when i was the geology student at grand university you had to go into a special laboratory to use for example the ability to fire a very concentrated beam of x. rays at a sample of rock powder and from the energy given off you can actually tell what minerals are in that rock curiosity actually has one of