Mike Schuh has more on what he calls the “intergalactic snowball.”
Educators have a different take.
“It’s called Comet ISON,” said Jim O’Leary of the Maryland Science Center.
NASA provided an image of ISON (above). It has a small head and a big tail.
“That tail can get tens of millions of miles long, so it’s huge,” O’Leary said.
But in its middle, it’s just dirt and ice three miles across.
Three miles is large enough to comfortably fit between the shores spanned by the Bay Bridge and its approach ramps.