Back in the day, it used to be that most new comets and asteroids were discovered by astronomers diligently sitting at their eyepieces, spending one cold night after another patiently scanning the skies. The advent of robotic astronomy changed that, and now the vast majority of all celestial newcomers are found automatically.
But Australian "amateur" astronomer Terry Lovejoy changed that last week: not only did he discover a comet — which isn’t that unusual, though still cool — but it turns out to be a sungrazer, a comet that plunges deep down to the center of the solar system, practically skimming the Sun’s surface.
Here is Lovejoy’s discovery image:
This is a combination of three images; the comet moves between exposures a bit so he re-centered the comet in each shot and added them together. It’s the fuzzy blob in the middle of the frame. The comet’s official name is C/2011 W3 (Lovejoy), and on December 16th it will pass just about
880,000 km (500,000 miles) from the Sun’s surface — only a little bit more than than the radius of the Sun itself! 180,000 km (110,000 miles) — less than half the distance from the Earth to the Moon!* This may be a death dive, since many such comets don’t survive the intense heat of the Sun from that distance. Comets are composed of lots of rock held together by ice, so when the ice vaporizes, the comets disintegrates.