avrtya rodasi kham ca
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the rays of the two brahmastras combined, a great circle of fire, like the disc of the sun, covered all outer space and the whole firmament of planets.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The heat created by the flash of a brahmastra resembles the fire exhibited in the sun globe at the time of cosmic annihilation. The radiation of atomic energy is very insignificant in comparison to the heat produced by a brahmastra. The atomic bomb explosion can at utmost blow up one globe, but the heat produced by the brahmastra can destroy the whole cosmic situation. The comparison is therefore made to the heat at the time of annihilation.