Top 84 Quotes & Sayings by John M. Grunsfeld - Page 2

Here on Earth, we're exposed to asteroids hitting the Earth, eventual changes in the Sun, changes in the Earth's climate, things we're doing to the Earth's climate. If we want to survive, we need to become a multi-planet species. That's further down the road, but the first wave is going to be the explorers.

All indications are that three and a half billion years ago, Mars looked like Earth. It had lakes. It had rivers. It had river deltas. It had snow-capped peaks and puffy clouds and blue sky. Three and a half billion years ago, it was a happening place. The same time on Earth, that's when life started. So did life start on Mars?

It's pretty amazing to me that we have had a space shuttle program that's lasted for 30 years - for one space shuttle. That's quite an achievement.

Are we alone? Many, many people on planet Earth want to know. We are on the cusp of being able to answer that question... because of the investments we're making in space technology.

There's no question that if we stay on planet Earth and never leave, that eventually we'll be wiped out.

Because of Hubble and other telescopes, we've now discovered that there are probably planets around every star, or virtually every star. There are solar systems around most stars. And the fact that we're here on a planet, Earth, means that it's likely there's lots of other Earths out there.

I think that space exploration as a broad activity is the most important things that humans can do. I've always found it fascinating, interesting, compelling, and I have a drive to go out into space.

When I grew up as a kid, we didn't know there were any other planets outside of our own solar system. It was widely speculated that planet formation was an incredibly rare event and that it's possible that other planets just don't exist in our galaxy, and it's just this special situation where we happen to have planets around our sun.

When I first went to Hubble, as an astronomer and as a scientist, it was a dream come true. And as an astronaut, the Hubble missions are premiere missions because Hubble is so important to science, so important to humanity, that it's just a very special event. But as an astronomer, it was sort of the holy grail of missions.

Hubble uniquely has been able to look in the atmosphere of a planet orbiting a nearby star and figure out what's in that atmosphere.

There's a perspective that I've gained as an astronaut that I didn't get from my science activities. In my science activities, I learned by the seat of my pants. Spending 17 years as an astronaut, I learned the NASA formalism of systems engineering as if my life depended on it. Literally.

Sciences are being unified by the search for life in the universe.

The Hubble Space Telescope, which was designed for extreme servicing, you know, we can fix everything. And the James Webb Space Telescope, where we can fix nothing. It has to work the first time. And it's a very complicated telescope.

Hubble has really opened our eyes to what the universe is made of, its structure, and has helped us learn how little we know about the universe.

Life outside of Earth is probably going to be really hard to find.

We don't know how many planets we're going to have to examine before we find life, and not finding it on 10 or 100 doesn't mean it's not there. This may be very tricky.

I see no difference between scientific exploration and human exploration.

The surface of Mars is bathed in ultraviolet light, bathed in radiation. Mars's magnetic field is essentially gone, so the surface of Mars is essentially sterilized.

The most striking thing to me about human space flight and my own personal experience is that I've seen dramatic changes on Earth. We humans are rapidly changing the planet. I've watched Amazonia as the rainforest has been cut down. That's something I've seen out the window. I'm very worried about that.

I'm absolutely compelled for NASA to send international astronauts to Mars to find out if Mars ever harbored life.

I kind of feel like I found my cause in life servicing the Hubble Space Telescope.

If I could live in space, I would definitely do that.

Getting a team of scientists on Mars could be transformative.

The strangest thing I've found is that when I got to space, I felt more comfortable in space that I've ever been on Earth before. I just felt this is my home.