Gamma Ray Bursts (GRB’s) are both the most powerful explosions in the universe and the most mysterious.  About once a day, a burst of high energy radiation (including X-Ray to gamma ray wavelengths) reaches us from one of these distant explosions and nobody knows what causes them.  NASA’s Swift satellite, launched in 2004, is an orbital observatory designed specifically to detect GRB’s and report them to ground-based observatories around the world.  Because GRB’s arrive from unpredictable directions and are extremely brief, lasting from a few milliseconds up to several minutes, Swift has to be able to respond extremely, er, swiftly.

On 21 June, Swift was blinded by an unexpectedly bright GRB.  The intensity of the X-Rays hitting Swift’s sensors was so intense that it shut them down temporarily – an unprecedented event.  According to Dave Burrows, lead scientist for Swift’s X-ray telescope, this GRB was by far the brightest light source of any kind ever detected at cosmological distances.

There are several competing theories as to what causes GRB’s.  Some scientists think that they signal the birth of a black hole in a massive stellar explosion, while others think they’re the product of the collision of two neutron stars.  The truth could even be something far stranger, and so long as Swift keeps returning surprising results like this one, scientists can be confident of eventually having enough data to find the solution.  

 

Universe Today has a more detailed report on this event here: http://www.universetoday.com/2010/07/14/swift-briefly-blinded-by-mega-x-ray-blast/