A bit is a basic unit of binary information, having one of only two values. Could be yes or no, on or off, plus or minus. In digital computing, communication, and storage, it’s either 0 or 1. One byte is 8 bits. A kilobyte is about a thousand bytes. A megabyte is about a million bytes—the length of an average novel. A gigabyte is roughly a billion bytes. My computer has 10 gigs of storage capacity, which I have not come close to using in the four years since I bought it. A common smartphone, of course, processes that much data a month easily.
A terabyte is 1,024 gigabytes, or about the same information stored in a large public library or on 1,600 regular CDs.
A petabyte is 1,024 terabytes. Put that much content on CDs and it would create a stack 878 feet tall (223,000 discs). It is 1,125,899,906,842,624 bytes.
There’s a telescope under construction near La Serena in Chile (been there), called the Large Synoptic Survey Telescope, which will automatically collect fifteen terabytes of data PER NIGHT. During its first decade it will amass 54,750 terabytes, or 53.5 petabytes. That’s enough to fill stacked Blue-ray discs to a height of 15,750 feet. An incredibly rich tower of data. In that time its instruments will capture 40 billion objects in fine detail (its camera alone has 3.2 billion pixels), map the structure and evolution of our Milky Way Galaxy, count asteroids, explore transient events like supernovae, and create a stop-motion movie of much of the celestial sphere. It will vastly increase our knowledge of this universe we live in.
We have other telescopes around the planet and in space that are constantly gathering ever more refined data, as well.
In astronomy, as increasingly in other scientific disciplines, the task has rapidly evolved from collecting enough data to draw meaningful conclusions, to being able to efficiently mine the fantastic avalanche of raw data now streaming in for the priceless knowledge certainly veined therein.
The years ahead will be exciting.