Dimitar Sasselov Quotes

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.

I should say we know that there are many, many other Earths out there. We're almost certain that there will be upwards of a billion Earth-like planets in our galaxy alone, so there is no lack of real estate where life might happen, but what we don't know is how likely it is given the real estate, given a wonderful pristine planet like Earth how likely is it that life will pop up inhabited? We don't know the answer to that.

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.

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

I do definitely believe that there is life away from this planet. I mean, we've kind of established that with the fact that we found bacteria on meteorites, and we've kind of used that to backtrack and show how this Earth, this planet, could have formed the ability to sustain life in the first place.

Stars, of course, are too hot to support life, so wherever life might exist in the universe, it has to be on planets or moons that are warmed, but not incinerated, by the stars they travel around.

If we do discover more than one type of life on Earth, we can be fairly certain that the universe is teeming with it, for it would be inconceivable that life started twice here but never on all the other earth-like planets.

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.

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

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

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

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.

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.

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

The math is dead simple: it seems that the frequency of planets able to support life is roughly one percent. In other words, a billion or more such worlds exist in our galaxy alone. That's a lot of acreage, and it takes industrial-strength credulity to believe it's all bleakly barren.

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.

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

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.

Our field is very focused on finding Earth 2.0, and anything we can do to narrow the search is helpful.