Dimitar Sasselov Quotes

Every observation that we make, every mission that we send to various places in the solar system is just taking us one step further to finding that truly habitable environment, a water-rich environment.

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.

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.

No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.

Mars is the only place in the solar system where it's possible for life to become multi-planetarian.

The cosmos is three times as old as Earth. During most of creation's 14 billion year history, our solar system wasn't around. Nonetheless, the early universe still had the right stuff for life, and contained worlds that were just as suitable for spawning biology and intelligence as our own.

What we expect to find, certainly in our own solar system, are probably simple single or multiple-cell forms of life. To get to intelligent life takes stability of conditions over huge, long periods of time.

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.

We're going to understand that there is life on other bodies in the solar system.

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.

The bottom line is, like, one in five stars has at least one planet where life might spring up. That's a fantastically large percentage. That means in our galaxy, there's on the order of tens of billions of Earth-like worlds.

The usual metric for whether a planet is habitable or not is to ascertain whether liquid water could exist on its surface. Most worlds will either be too cold, too hot or of a type (like Jupiter) that may have no solid surface and be swaddled in noxious gases.

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.

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.

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

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.

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.

Ultimately, what we're looking for in the long run is to find other Earth-like planets.

It's one of the big mysteries about Venus: How did it get so different from Earth when it seems likely to have started so similarly? The question becomes richer when you consider astrobiology, the possibility that Venus and Earth were very similar during the time of the origin of life on Earth.

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.

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.

This is what the Mars Science Laboratory (MSL) represents. Experimental, explorational science. Learning about Mars as a new world. Discovering new things that will tell us about the history of our solar system, help reveal the secrets of life, and continue blazing the trail that may someday be traveled by the rest of us.

Just speaking for myself, I think the return of people to the Moon has a lot to offer for understanding the formation and evolution of terrestrial worlds; so would the exploration of near-Earth asteroids by people.

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.

Prebiotic chemistry on other worlds is going to be common. Plenty of small rocky planets will have similar chemistry. It's almost a given.