Quotes About Astronomy

Sir William Herschel was the first person to discover a planet beyond those easily visible to the naked eye, and he was ready to name it after the King—always a safe bet when you are his subject. Had Sir William succeeded, the planet list would read: Mercury, Venus, Earth, Mars, Jupiter, Saturn, and George.

Uranus was almost named George.

Astronomy, because of that peculiar history, has a fascinating legacy of early contributions by women.

Si la velocidad orbital de la Tierra fuera mayor que la raíz cuadrada del doble de su velocidad actual, nuestro planeta alcanzaría una «velocidad de escape» y, como cabe suponer, escaparía del sistema solar. Podemos

No, it's not Pluto. Get over it.

This general flattening of objects that rotate is why Earth's pole-to-pole diameter is smaller than its diameter at the equator. Not by much: three-tenths of one percent—about twenty-six miles.

The stars of the Milky Way galaxy trace a big, flat circle. With a diameter-to-thickness ratio of one hundred to one, our galaxy is flatter than the flattest flapjacks ever made. In fact, its proportions are better represented by a crepé or a tortilla.

By now, one second of time has passed. The universe has grown to a few light-years across,†† about the distance from the Sun to its closest neighboring stars.

Decade by decade: estimates of Pluto's size got smaller and smaller.

Earth has also tidally locked the Moon, leaving it with identical periods of rotation on its axis and revolution around Earth. Wherever and whenever this happens, the locked moon shows only one face to its host planet.

The universe today is 13.8 billion years old. By 22 billion years, the Sun will have finished its main-sequence lifetime and will have become a white dwarf. The Andromeda galaxy will have crashed into the Milky Way.

In short, were it not for our ability to analyze spectra, we would know next to nothing about what goes on in the universe.

We are seeing these nearby stars, not as they are at the present moment, but as they were 4 years ago

Earth's brightness is less than one-billionth that of the Sun, and our planet's proximity to the Sun would make it extremely hard for anybody to see Earth directly with a visible light telescope.

One substantial hunk of junk led to the formation of the Moon. The unexpected scarcity of iron and other higher-mass elements in the Moon, derived from lunar samples returned by Apollo astronauts, indicates that the Moon most likely burst forth from Earth's iron-poor crust and mantle after a glancing collision with a wayward Mars-sized protoplanet.

Thus, helium became the first and only element in the chemist's Periodic Table to be discovered someplace other than Earth.

Dark matter is dark; that means it does not interact with photons

Sir William Herschel was the first person to discover a planet beyond those easily visible to the naked eye, and he was ready to name it after the King—always a safe bet when you are his subject. Had Sir William succeeded, the planet list would read: Mercury, Venus, Earth, Mars, Jupiter, Saturn, and George. Fortunately, clearer heads prevailed and the classical name Uranus was adopted some years later.

If you must know, the brightest star in the nighttime sky is Sirius, the Dog Star.

We begin with the stars, then ascend up and away out to the galaxy, the universe, and beyond. What did Buzz Lightyear say in Toy Story? "To Infinity and Beyond!" It's a big universe. I

People who navigate by the stars know that the altitude of Polaris you observe is equal to your latitude on Earth.

Of all the sciences cultivated by mankind, Astronomy is acknowledged to be, and undoubtedly is, the most sublime, the most interesting, and the most useful. For, by knowledge derived from this science, not only the bulk of the Earth is discovered . . . ; but our very faculties are enlarged with the grandeur of the ideas it conveys, our minds exalted above [their] low contracted prejudices. JAMES FERGUSON, 1757†

If you feed a black hole, its event horizon (that boundary beyond which light cannot escape) grows in direct proportion to its mass, which means that as a black hole's mass increases, the average density within its event horizon actually decreases. Meanwhile, as far as we can tell from our equations, the material content of a black hole has collapsed to a single point of near-infinite density at its center.

In our own solar system, for example, everything that is not the Sun adds up to less than one fifth of one percent of the Sun's mass.