A fireball that blazed brighter than the full moon as it streaked across New Mexico's sky on 9 November may be related to Comet Encke and perhaps to the object that exploded over Tunguska in 1908, flattening more than 2,000 sq km of Siberian forest.

Every October and November bring a flurry of fireballs from a pair of meteor showers whose meteors diverge from radiant points in our E evening sky. Called the Northern and Southern Taurids after the constellation Taurus, their meteors are relatively slow at 27-29km per second but few in number, rarely more than five per hour even under ideal dark skies. They do, though, include a good proportion of fireballs which we can define as a meteor that rivals or surpasses Venus in brightness. There seem to have been more fireballs than usual this year.


Comment: There have been more fireballs than usual this year. We wonder what's 'up'?


Taurids follow similar solar orbits to Comet Encke, though it is not clear whether their material comes from that comet or an earlier and larger predecessor. One theory for the origin of the Tunguska object is that it, too, was a fragment of Comet Encke or its predecessor.

Another meteor shower, the Leonids, peaks on Saturday but is likely to fall well short of the stunning displays it gave a few years ago. Its very swift (72km per second) meteors stream away from a radiant in the Sickle of Leo which climbs from low in the ENE at 23:00 to high on the meridian by dawn. Peak rates may touch 15 per hour but should already be declining as the radiant rises that night.