David Grinspoon Quotes

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 do a lot of work with NASA and am involved in research projects studying planetary evolution, Earth-like planets, and potential conditions for life elsewhere.

In days gone by, scientists would speak solemnly about our solar system's 'habitable zone' - a theoretical region extending from Venus to Mars, but perhaps not encompassing either, where a planet would be the right temperature to have liquid water on its surface.

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.

There are other planets besides the Earth and Mars. I'd like to remind you that studying Venus is vital to understanding life elsewhere.

I'm an astrobiologist, and I come from a planetary science background, so in a very broad sense, I study the evolution of planetary environments.

There's a lot to do in space. I want to learn more about the greenhouse effect on Venus, about whether there was life on Mars, about the environment in which Earth and the Sun is immersed, the behavior of the Sun.

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.

Because Hubble's been up so many years now, it's actually given us a window to things like... how planets' atmospheres actually change, evolve... over time.

Because Alpha Centauri is so close, it is our first stop outside our solar system. There's almost certain to be small, rocky planets around Alpha Centauri A and B.

By going to Pluto, we have a chance to anchor, with real data, models of the early evolution of Earth's atmosphere.

The first exoplanet to be found around a sun-like star was discovered in 1995, just two years before I began studying exoplanet detection.

The universe has told us the most common types of planets are small planets, and our study shows these are exactly the ones that are most likely to be orbiting Alpha Centauri A and B.

The story seems to be that almost every star has a planetary system... and, also, the definition of 'habitable zone' has expanded. In our system, it used to be that only Mars and Earth were potentially habitable. Now we've got an ocean on Europa... Titan.

As our sensitivity improves, we are finally seeing planets with longer orbital periods, planetary systems that look more like our solar system.

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.

The mission of NASA's Kepler telescope is to lift the scales from our eyes and reveal to us just how typical our home world is. Kepler operates by measuring the dimming of stars as planets pass ('transit') in front of them. It has found thousands of previously unknown worlds.

Mars was this water-based planet, and we know there was stable water on the surface for a long time, which is critical for life having a chance to develop.

Scarce any problem will appear more hard and difficult, than that of determining the distance of the Sun from the Earth very near the truth: but even this... will without much labour be effected.

Mars is much closer to the characteristics of Earth. It has a fall, winter, summer and spring. North Pole, South Pole, mountains and lots of ice. No one is going to live on Venus; no one is going to live on Jupiter.

Planets that don't currently sport plate tectonics, such as Venus and Mars, are scarcely habitable. Tectonics might be a requirement of any world that aspires to a rich diversity of life.

We are the laws of chemistry and physics as they have played out here on Earth, and we are now learning that planets are as common as stars. Most stars, as it turns out now, will have planets.

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.

By the mid-17th century, telescopes had improved enough to make visible the seasonally growing and shrinking polar ice caps on Mars, and features such as Syrtis Major, a dark patch thought to be a shallow sea.

From the moment of using rocket devices, a great new era will begin in astronomy: the epoch of the more intensive study of the firmament.