Actually....... that's much more likely:

Scientists estimate that Earth contains 7.5 sextillion sand grains. That is 75 followed by 17 zeros.[/quote]
Let's visualize it:
7500000000000000000 grains of sand. And that's not only the beaches, that includes the much larger deserts too.

A 128 bit private key gives:
[url=https://www.wolframalpha.com/input/?i=2%5E128]340282366920938463463374607431768211456 possibilities. That's 45370982256125128461 possibilities for each grain of sand.

Super computers are no match for 128 bit encryption.