Planetary Comparison Quotes

When we explore other planets, we learn a lot about our own.

Mars is essentially in the same orbit. Mars is somewhat the same distance from the Sun, which is very important. We have seen pictures where there are canals, we believe, and water.

One of the jovian moons, Europa, is coated with twice as much liquid water as is sloshing around our planet.

When you look at Venus and the Earth, they formed at about the same place in the solar system. They're made of about the same materials; they're about the same size.

The body is extremely important to me, because it is a planet. For instance, if you compare Earth and an astronomer, you will see that the man is a planet.

Something bad happened on both Mars with its dried-up watercourses and Venus with its runaway greenhouse effect. Could something bad happen on Earth too? Our species currently turns row upon row of environmental knobs, without much regard to long-term consequences.

One of the first thoughts I had, when doing early exoplanet research, was that Earth and its many companions seemed very different from the planetary systems we were detecting.

Venus has a runaway greenhouse effect. I kind of want to know what happened there because we're twirling knobs here on Earth without knowing the consequences of it. Mars once had running water. It's bone dry today. Something bad happened there as well.

There is good evidence that Venus once had liquid water and a much thinner atmosphere, similar to Earth billions of years ago. But today the surface of Venus is dry as a bone, hot enough to melt lead, there are clouds of sulfuric acid that reach a hundred miles high and the air is so thick it's like being 900 meters deep in the ocean.

Venus and Mars are our next of kin: they are the two most Earth-like planets that we know about. They're the only two other very Earth-like planets in our solar system, meaning they orbit close to the sun; they have rocky surfaces and thin atmospheres.

I am sorry to say that there is too much point to the wisecrack that life is extinct on other planets because their scientists were more advanced than ours.

Life can be less mysterious than we make it out to be when we try to think about how it would be on other planets. And if we remove the mystery of life, then I think it is a little bit easier for us to think about how we live, and how perhaps we're not as special as we always think we are.

Earth might one day soon resemble the planet Venus.

A century ago, scientists believed there was only one obvious stomping ground for alien biology in our solar system: Mars. Because it was reminiscent of Earth, Mars was assumed to be chock-a-block with animate beings, and its putative inhabitants got a lot of column inches and screen time.

If Neptune were analogized with a Chevy Impala in mass, then how big is pluto compared to that? Pluto would be a matchbox car sitting on the curb.

Personally, I don't think there's intelligent life on other planets. Why should other planets be any different from this one?

You cannot study other planets without referring to Earth and without applying the techniques and the insights of Earth science. And you cannot really do a good job understanding the Earth without the insights from planetary exploration.

Antarctica is a paradise compared to Mars.

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 going to be a bummer if Mars turns out to be like us.

Once we get beyond Mars, which formed from the same stuff as Earth, the likelihood that life is similar to what we find on this planet is very low.

I'm sure that there are places in the deserts in Australia that could be similar to where we might want to go on Mars.

Pluto is as far across as Manhattan to Miami, but its atmosphere is bigger than the Earth's.

It's quite possible there's as much lightning on Venus as on Earth.

The reason you see so many volcanoes on Venus is partly due to the fact that there's virtually no erosion there. So on Venus, you're seeing features, some of which are hundreds of millions of years old on the surface. On Earth, we do not see any surface features nearly that old - you only see much more recent features.