Seth Shostak Quotes

Many different planets are many different distances from their host star; we find ourselves at this distance because if we were closer or farther away, the temperature would be hotter or colder, eliminating liquid water, an essential ingredient for our survival.

Life is extremely resilient once it takes hold, but it requires rich chemistry, large energy sources, and stability, right from the beginning. The comparative planetology of our solar system makes it seem like those initial conditions are hard to come by.

We do care about planets like the Earth because by now we understood that life as a chemical system really needs a smaller planet with water and with rocks and with a lot of complex chemistry to originate, to emerge, to survive.

Weather forecast for Jupiter's South Equatorial Belt: cloudy with a chance of ammonia.

Diminutive worlds are more likely to be rocky, and lapped by oceans and atmospheres. In the vernacular of 'Star Trek,' these would be M-class planets: life-friendly oases where biology could begin and bumpy-faced Klingons might exist.

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.

Super-Earths are how we call a family of planets... up to two times larger and about ten times more massive than the Earth.

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.

Jupiter, a world far larger than Earth, is so warm that it currently radiates more internal heat than it receives from the Sun.

We think that life develops spontaneously on Earth, so it must be possible for life to develop on suitable planets elsewhere in the universe. But we don't know the probability that a planet develops life.

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.

Life is fragile: it thrives only in a narrow range of temperatures between freezing and boiling. How lucky that our planet is just the right distance from the sun: a little farther, and the death of the perpetual Antarctic winter - or worse - would prevail; a little closer, and the surface would truly fry anything that touched it.

Earth as an ecosystem stands out in the all of the universe. There's no place that we know about that can support life as we know it, not even our sister planet, Mars, where we might set up housekeeping someday, but at great effort and trouble we have to recreate the things we take for granted here.

I am not sufficiently conceited to think that my sun is the only one with a family of planets and, therefore, that our little earth is unique. Once we admit that the other stars probably also have planets, at any rate a goodly proportion of them, it is more than likely that a large fraction of these will be the right size to keep on their surface water and, possibly, an atmosphere of some sort; and, furthermore, at the proper distance from their parent sun, to maintain a suitable temperature.

By monitoring auroral activity on exoplanets, we may be able to infer the presence of water on or within an exoplanet.

Generally speaking, exoplanets can be any size, and they are found in a wide range of orbits. Some have massive gas atmospheres; others are smaller with an icy or rocky composition.

I would argue that in any habitable zone that doesn't boil or freeze, intelligent life is going to emerge because intelligence is convergent.

There was a long history of people believing there was life on Venus. It was about the same size as Earth. It had clouds. It was commonly believed it was tropical - wet, hot and steamy.

Naturally, we think that finding another Earth-like planet is identifying a site that's at least friendly here for the evolution of life. The primary goal of the Kepler mission is to statistically assess the occurrence of these small terrestrial worlds.

55 Cancri is extraordinarily rich in heavy elements and extraordinarily efficient at making planets - much more so than our sun - and those elements are the very ones you need to make planets that aren't just gas giants.

We go to learn about our solar system, to search for life, and to understand what happened to Mars so we avoid it ourselves.

I think Pluto has to be considered among the places in the solar system that are possible homes for life.

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.

Among the plausible niches for extraterrestrial life in our solar system, the clouds of Venus are among the most accessible and the least well explained.