... Tonight's Sky . ... Observing . ... Star Atlas . ... Supernova showered Earth with radioactive debris . ... Blast from the past . ... The view of the light echoes from Tychoт??s supernova. ... Lead project astronomer at Subaru, Tomonori Usuda, said "using light echoes in supernova remnants is time-traveling in a way, in that it allows us to go back hundreds of years to observe the first light from a supernova event. ... Only registered members of Astronomy.com are allowed to comment on this article....