First illustration of a gravity well?

[Squink]

Larry Niven, Ringworld, 1970:

They took off on reactionless thrusters, to avoid damaging the island. Half an hour later they had left the feeble gravity wells of the puppeteer rosette. It occurred to Louis then that aside from Nessus, whom they had brought with them…

He doesn’t use the term in his 1967 story “Neutron Star”

[Squink]

I suspect that ‘gravity well’ gained popularity as Apollo capsules began to enter regions of space where the moon’s gravity dominated. It seems like a term Walter Cronkite or Arthur C. Clarke might have gotten a kick out of using.

[Fiendish_Astronaut]

Poul William Anderson used the term “gravity well” in his 1963 sci fi book Industrial Revolutions:

It’s actually harder to maintain human-type conditions on so big a mass, with a useless atmosphere around you, than on a lump in space like this. And the gravity wells are so deep.

Though I’m not claiming it’s the first use of the term!

[bonzer]

@Panurge

ETA: What about the origin of the term “Gravity well”? I suspect that is arose from the visual metaphor, but I cannot find out who coined the phrase.

There’s an interesting step towards the usage in a 1949 paper “The Dynamics of Space-Flight”, published by Arthur C. Clarke in the Journal of the British Interplanetary Society (vol.8, no.2, XXVII, p71-84; it’s reprinted in his Ascent to Orbit, Wiley, 1984).

The Earth’s gravitational field, therefore, may be regarded as producing a sort of valley or pit 4,000 miles (6,300 kilometeres) deep out of which we have to climb if we wish to travel to other worlds. The walls of the pit are very steep near the beginning, but rapidly flatten out with increasing distance (Fig. 2).

The diagram is a straightforward 2D graph of the Earth’s gravitational potential (with a little dink to one side to show the Moon’s).
The rest of the article goes on to apply the term “gravitational pit” to other bodies including the Moon and other planets.

In 1949 the prior scientific literature on space flight wasn’t huge (celestial mechanics is another matter) and Clarke would have been familiar with much of it. Suggesting that “gravity well” itself postdates 1949.

[Panurge]

Excellent. You guys are good. (I knew you would be). Thank you for the input so far!