File:Tsar Bomba fireball.jpg

Fair use for Tsar Bomba and History of the Teller–Ulam design
The image linked here is claimed to be used under fair use as:
 * 1) It is a historically significant photo of an important event;
 * 2) It is of much lower resolution than the original (copies made from it will be of very inferior quality)
 * 3) The photo is only being used for informational purposes.
 * 4) Its inclusion in the article adds significantly to the article because it depicts one of the most important milestones of the project
 * 5) The photograph belongs to Russian department of Atomic Energy Minatom. Introducing the picture  on our server does not interfere with their ability to develop and detonate new nuclear devices