The short answer is that no one can. It simply can’t be done. Even with all our technology and the technology to come, no one will ever be able to count the stars. We won’t even be able to get close to counting all the stars. Of course, most of them are out of sight. But that’s only part of the problem. One critical reason that this straight-forward accounting task is so out of reach, in fact, impossible, is due to the sheer magnitude of the number itself. It’s astronomical!

### How Much Progress has Astronomy Made?

So what is this very big number? Simply stated, the number of stars is 10^{23}. But that doesn’t mean much at first blush. We could state it differently. It is 100 sextillion. That’s not much better! We can write it out as 1 followed by 23 zeros, which looks like 100,000,000,000,000,000,000,000. That’s impressive, but it’s not hard to count 23 zeros. How can we, as insignificant specs on a tiny planet, millions of miles from one small star, our sun, get an appreciation for how many more stars exist? Let’s break it down to a smaller number.

Millions of stars have already been counted, named, and listed in star catalogs. That still leaves the same number left to count because the number counted is only 0.0000000000001% of the total. That’s insignificant! It’s like we haven’t even started. Therefore, the next best thing is to count galaxies and just estimate the number of stars. That’s the best we can ever do. But how good is that, since we can neither see nor catalog all the galaxies? We can take a sample from our own galaxy and estimate that the average galaxy has about 10^{11} stars. That’s a rough estimation because we can’t count all the stars in our galaxy, and we can’t see many galaxies well enough to make multiple estimates. In other words, we assume a lot. To complicate it even more, we look at the sky, assume that what we see is what we think we see, and estimate the number of galaxies to be between 10^{11} and 10^{12}. We can’t even count the galaxies. To help visualize the counting process, let’s bring it down to Earth. The number of stars in the sky is supposed to be to the same order as the number of grains of sand on all the beaches of the world. Let’s compare counting the stars to counting the grains of sand in the world.

### Try Counting Sand

Howard C. McAllister at the University of Hawaii estimated the number of grains of sand on all the beaches to be 7.5 x 1018. That’s one hundred thousand times smaller than the estimated number of stars, but it’s a good place to start. In a math experiment, Jochem Hendricks together with 12 assistants counted 3,281,579 grains of sand, which took them approximately 1,000 hours. How long would it take the Hendricks group of 13 to count McAllister’s sand? Do the math. Divide!

If all the 7 billion people in the world counted day and night, it would take five million years to count all the sand on the beaches. That’s only counting and doesn’t include labeling them to keep from counting one twice, which would be necessary in practice. Going once step further, it would take around 30 lifetimes of the universe for the world population to count the stars. That’s not going to happen!