Who said what on Planetary Defense..

Here are some quotations related to planetary defense to remind us about the threat.

"The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!"
- Larry Niven, quoted by Arthur Clarke in interview at space.com, 2001.

"I only hope that we shall not wait to adopt the [space] program until after our astronomers have reported a new and unsuspected aster[oid] moving across their fields of vision with menacing speed. At that point it will be too late!"
- Wernher von Braun, "A Plea for a Coordinated Space Program" in The Complete Book of Outer Space, 1953.

"Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring--not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive... If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds."
- Carl Sagan, Pale Blue Dot, 1994.

"Knowing what we know now, we are being irresponsible in our failure to make the scientific and technical progress we will need for protecting our newly discovered severely threatened and probably endangered species--us. NASA is not about the 'Adventure of Human Space Exploration,' we are in the deadly serious business of saving the species. All Human Exploration's bottom line is about preserving our species over the long haul."
- Astronaut John Young,"The Big Picture."

Link: "Space Quotes to Ponder"