In an earlier post I noted that last month NASA had mentioned WISE finding dark and dead comets for the first time (at least as recorded on the Internet). I thought it kind of odd that well into a mission the agency begins speaking of a dangerous phenomena that had not been previously and specifically identified as quarry for the Infrared Telescope. Mind you, there was a fair amount of buzz about “asteroids” and “NEO” detection by WISE — but never a word said about “dark” and “dead” comets. Now, a couple of weeks later, the agency is chattering away to New Scientist about some pretty spooky stuff:
In its first six weeks of observations, it has discovered 16 previously unknown asteroids with orbits close to Earth’s. Of these, 55 per cent reflect less than one-tenth of the sunlight that falls on them, which makes them difficult to spot with visible-light telescopes. One of these objects is as dark as fresh asphalt, reflecting less than 5 per cent of the light it receives. Many of these dark asteroids have orbits that are steeply tilted relative to the plane in which all the planets and most asteroids orbit. This means telescopes surveying for asteroids may be missing many other objects with tilted orbits, because they spend most of their time looking in this plane. Dark, Dangerous Asteroids found lurking near Earth, New Scientist, by David Shiga
Huh? Steeply tilted relative to the plane in which most asteroids travel? Thats means they are more appropriately called “comets” in my book. And a comet can come out of anywhere at any time. If there are lots of dark comets — NASA and the American impact frequency gurus have a lot of explaining to do.
Also notable is the rate at which they are being discovered — more than one per week. Something that was an obscure and dangerous beast a few weeks ago is now being located every few days.
These findings were predicted by the spot-on paper from Bill Napier and the Wickramasinghes in 2004 (below). They found the now proven comets by reverse engineering the amount of zodiacal dust. What genius, relative to the folks who never mention them — but spend millions finding them.