Planetary Formation Quotes

The cosmic calendar compresses the local history of the universe into a single year. If the universe began on January 1st it was not until May that the Milky Way formed. Other planetary systems may have appeared in June, July and August, but our Sun and Earth not until mid-September. Life arose soon after. We humans appear on the cosmic calendar so recently that our recorded history occupies only the last few seconds of the last minute of December 31st.

When I grew up as a kid, we didn't know there were any other planets outside of our own solar system. It was widely speculated that planet formation was an incredibly rare event and that it's possible that other planets just don't exist in our galaxy, and it's just this special situation where we happen to have planets around our sun.

If the rate of expansion one second after the Big Bang had been smaller by even one part in a hundred thousand million million, it would have recollapsed before it reached its present size. On the other hand, if it had been greater by a part in a million, the universe would have expanded too rapidly for stars and planets to form.

We don't know that Venus had oceans, but there's every reason to believe it did.

Earth took her shining station as a star, In Heaven's dark hall, high up the crowd of worlds.

Bubbles are round for the same reason that planets are spherical. The universe itself is like bubbles.

When you look at Venus and the Earth, they formed at about the same place in the solar system. They're made of about the same materials; they're about the same size.

We can trace the elements. They were forged in the centers of high-mass stars that went unstable at the ends of their lives, they exploded, scattered their enriched contents across the galaxy, sprinkled into gas clouds that then collapsed and formed stars and planets and life.

Even to make the first cell possible, stellar space required to be swept of matter, suns must needs be broken up, and planets cool, the agents of geology labour millennium after millennium at the unfinished earth to prepare a material resting-place for the coming guest. Consider all this, and judge if Creation could have a sublimer meaning, or the Human Race possess a more splendid genesis.

The physical fabric of the world had to be such as to enable that ten billion year preliminary evolution to produce the raw materials of life. Without it there would not have been the chemical materials to allow life to evolve here on earth.

No one planet can tell us everything about the universe, but Neptune seems to hold more than its share of information about the formation of our own solar system - as well as the solar systems beyond.

A 'serious' scientist in 1992 or 1993 had to admit the possibility that planets were really rare, that most stars might not have planets. We've gone from there to here - where most stars have planets.

If you go to planetary science meetings and hear technical talks on Pluto, you will hear experts calling it a planet every day.

Voyager found Saturn to be a planet with a complex interior, atmosphere, and magnetosphere. In its rings - a vast, gleaming disk of icy rubble - the mission recorded signs of the same physical mechanisms that were key in configuring the early solar system and similar disks of material around other stars.

My field is called planetary science.

Kepler's blown the lid off everything we know about extra-solar planets.

Of course Pluto is a planet: It's massive enough to have its shape controlled by gravity rather than material strength, which is the hallmark of planethood.

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

Small bodies in our solar system, like comets and asteroids, help us understand how the solar system formed and provide opportunities to advance exploration.

I actually started my career in planetary science with a master's thesis on Pluto.

It now appears that essentially every star has a planetary system. In the very beginning, we thought at best half.

Most of the solar system resides beyond the orbits of the asteroids. There is more to learn there about general planetary processes than on Mars.

Estimates are that at least 70 per cent of all stars are accompanied by planets, and since the latter can occur in systems rather than as individuals (think of our own solar system), the number of planets in the Milky Way galaxy is of order one trillion.

Earlier generations of stars in the galaxy could well have had planets. But really, there was only hydrogen and helium to work with, so they'd all be gas giants and not small, rocky planets.

After all, the universe required ten billion years of evolution before life was even possible; the evolution of the stars and the evolving of new chemical elements in the nuclear furnaces of the stars were indispensable prerequisites for the generation of life.