61.   Mission scientists say water is the key to determining whether life ever existed on Mars.

62.   Scientists suspect they will have to wait until then to determine, beyond a doubt, whether life ever existed on Mars.

63.   So far, there is no evidence from the Surveyor mission that life existed or could exist on Mars.

64.   Such a scenario makes it more likely that life could have existed on Mars.

65.   Some scientists believe that if this is true, then there is a possibility life may exist there.

66.   The film presumes that life exists beyond Earth.

67.   The idea of life on the moons is speculation, but Williams said he thought it was quite likely that microbial life exists there.

68.   The information is key to understanding whether life ever existed or can exist there.

69.   They knew that a better life existed beyond the Iron Curtain.

70.   At the United Nations in New York, a spokeswoman offered a down-to-earth reaction to the discovery of possible evidence that life existed on Mars.