An AIM-9X Sidewinder air-to-air missile.
The AIM-9 Sidewinder is a heatseeking, supersonic, short range, US$85 000, air-to-air missile carried by fighter aircraft, and recently, some gunship helicopters. It's first flight was on September 1953, and it entered service in 1956. The manufacturers of this missile are Raytheon Company, Ford Aerospace, and Loral Corp.
The AIM-9 Sidewinder was named after the Sidewinder snake, which detects the prey via body heat or infrared radiation. The other reason is the peculiar snake-like flight pattern the early versions liked to follow when launched. The AIM-9 widely immitated and copied by many countries as it was the first truly effective air-air missiles. Some airforces still have variants, and upgrades of the Sidewinder still in active service for 5 decades. The latest version of it is the AIM-9X.
In the first few years when the Sidewinder was introduced, new aircrafts developed abandoned guns and added new racks on the wings for Sidewinders. The Air Force thought with this new weapon, dogfighting was obsolete. This assumption was a terrible mistake. During the Vietnam war, U.S. aircraft loses mounted and kills were lessened. Most Sidewinders fired failed to lock on or missed. They soon realised their mistake and dogfighting was introduced again. Modern planes still have guns, but most are intended as a last ditch effort.