The Search
for Mersenne
Primes
For centuries, mathematicians have tried to find larger and larger prime numbers. In recent
times, a Mersenne prime has always held the record of largest prime ever
discovered.
A project called GIMPS [Great Internet Mersenne Prime Search], started in 1996, has
enabled computer users around the world to participate in the search for everlarger Mersenne primes. By
downloading software from the internet, they can combine their machines' computing power, forming a "virtual
computer" far more powerful than any single machine that could be dedicated to this
task.
GIMPS made headlines in August, 2008, by finding a recordbreaking Mersenne prime more than 12
million digits long! The following month, it found the secondlongest known Mersenne prime, containing more than 11
million digits. (The August discovery won GIMPS a $100,000 prize which the Electronic Frontier Foundation had
offered to whomever first found a prime number with at least 10 million digits.)
With the help of GIMPS, a Norwegian mathematician found a new secondlargest Mersenne prime
(again, more than 12 million digits) in the spring of 2009.
How large can Mersenne primes be? Some mathematicians think there is no limit, while others
aren't sure. As computers get faster, and as more people join efforts like GIMPS, expect to see the record
shattered again and again!
