Telescopes on Earth cannot see this event. The sun is too bright. From its orbit 1.5 million km from Earth, however, SOHO is able to observe the comet's disintegration using an opaque disk to block the glare.
Sundiving comets are more common than you might think. SOHO has found more than 3000 of them. Most are members of the Kreutz family. Kreutz sungrazers are fragments from the breakup of a single giant comet many centuries ago. They get their name from 19th century German astronomer Heinrich Kreutz, who studied them in detail. Kreutz fragments pass by the sun and disintegrate almost every day. Most, measuring less than a few meters across, are too small to see, but occasionally a bigger fragment like this one attracts attention.
The comet is vaporizing furiously. Will it make it around the sun? Probably not. Monitor the SOHO realtime images page for developments.