A 1997 Time/Yankelovich poll revealed that one third of Americans are convinced that intelligent beings from other worlds have visited Earth. Of these, nearly two-thirds believe an alien spacecraft came down near Roswell (see Roswell Incident) and four-fifths believe the US government is not telling all that it knows about UFOs. In a 1998 poll conducted by the Marist Institute for the Planetary Society, 60% of those interviewed thought that there was intelligent life on other planets and of these, 47% thought that intelligence elsewhere would be more advanced than us (see extraterrestrial intelligence, more advanced than us), 40% thought it would be at about the same level, and only 13% thought it would be less advanced. To the question "Do you think life on other planets is friendly or hostile?", 86% thought it would be friendly and 14% hostile (see extraterrestrial intelligence, nature of).