A brontobyte is a measure of memory or data storage that is equal to 10 to the 27th power of bytes. There are approximately 1,024 yottabytes in a brontobyte. Approximately 1,024 brontobytes make up a geopbyte.
Brontobytes are sometimes represented by the symbol BB, but the prefix bronto- is not currently an official SI prefix that is recognized by the International Bureau of Weights and Measures. In 2010, following a campaign on the campus of the University of California, Davis, an online petition was created to have hella- become the official SI prefix for 1027. The suggested prefix originated from Southern California slang for "hell of a lot." The prefix was incorporated into the Google calculator in May 2010, but the campaign otherwise subsided.
There is nothing in existence currently measurable on the brontobyte scale, but internet of things and sensor data are the most common potential uses for brontobyte-level storage. The advent of technology like self-driving cars, which will generate enormous amounts of sensor data, could bring brontobytes as a unit into the storage media sphere.
Estimates and projections for future numbers of internet-connected objects differ, but if they keep growing at the current rate, they are sure to generate massive amounts of data in the near future. In 2015, Cisco Systems estimated that there were approximately 14.8 billion devices connected to the internet, and that number would grow to 50 billion in 2020, when brontobytes could potentially come into play.
For now, even yottabyte-scale storage has yet to enter the world of storage media. According to Paul McFedries' The Word Spy, it would take approximately 86 trillion years to download a 1-yottabyte file, and the entire contents of the Library of Congress would consume 10 terabytes.