Planet

"It is known that there is an infinite number of worlds, but that not every one is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so if every planet in the Universe has a population of zero then the entire population of the Universe must also be zero, and any people you may actually meet from time to time are merely the products of a deranged imagination."

"Outside intelligences, exploring the solar system with true impartiality, would be quite likely to enter the sun in their records thus: Star X, spectral class G0, 4 planets plus debris."

"Most known extrasolar planets (exoplanets) have been discovered using the radial velocity, or transit methods. Both are biased towards planets that are relatively close to their parent stars, and studies find that around 17–30% of solar-like stars host a planet. Gravitational microlensing, on the other hand, probes planets that are further away from their stars. Recently, a population of planets that are unbound or very far from their stars was discovered by microlensing. These planets are at least as numerous as the stars in the Milky Way."

"Gauss calculated the elements of the planet Ceres and his analysis proved him to be the first of theoretical astronomers no less than the greatest of arithmeticians."

"The important achievement of Apollo was demonstrating that humanity is not forever chained to this planet and our visions go rather further than that and our opportunities are unlimited."

"The only truly alien planet is Earth."

"The fact that we live at the bottom of a deep gravity well, on the surface of a gas-covered planet going around a nuclear fireball 90 million miles away and think that this to be the normal is obviously some indication of how skewed our perspective tends to be."

"Copernicus, who rightly did condemn This oldest system, formd a wiser scheme; In which he leaves the Sun at Rest, and rolls The orb terrestrial on its proper poles; Which makes the night and day by this career, And by its slow and crooked course the year. The famous Dane, who oft the modern guides, To earth and sun their Provinces divides: The earths rotation makes the night and day, The sun revolving through theccliptic way Effects the various seasons of the year, Which in their turn for happy ends appear. This scheme or that, which pleases best, embrace, Still we the fountain of their motion trace. Kepler asserts these wonders may be done By the magnetic vertue of the sun, Which he, to gain his end, thinks fit to place Full in the center of that mighty space, Which does the spheres, where planets roll, include, And leaves him with attractive force endud. The sun, thus seated, by mechanic laws, The earth, and every distant planet draws; By which attraction all the planets found Within his reach, are turnd in ether round."

"I remember on the trip home on Appolo 11, it suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didnt feel like a giant. I felt very, very small."

"I had rather be Mercury, the smallest among seven [planets], revolving round the sun, than the first among five [moons] revolving round Saturn."

"That the machine of Heaven is not a hard and impervious body full of various real spheres, as up to now has been believed by most people. It will be proved that it extends everywhere, most fluid and simple, and nowhere presents obstacles as was formerly held, the circuits of the Planets being wholly free and without the labour and whirling round of any real spheres at all, being divinely governed under a given law."

"It’s so hard to balance in our minds the knowledge that ‘the world’ is mundanely ‘a planet.’ The former is so holy; the latter merely a science project."