"Huge Meteor Plunges Into Sea Narrowly Missing Tug," reads the page one headline of Eureka's old daily, the Humboldt Standard, for Sept. 13, 1930. "Tug Humboldt was towing the Norwegian motorship Childar out to sea on a 300-yard line when the flaming missile, comprising several tons of molten rock, dropped between the two vessels ... off No. 8 Star Buoy, which stands about halfway between Samoa and the Bayside mill." Chief Engineer William P. Burrill gave a graphic description of the incident: "The meteor ... appeared to be about half as big as the tug, while it had a fiery tail that strung out for about forty feet ... The meteor hit the waters of the bay with a terrific impact, and a cloud of steam and water arose from the spot where it struck."
I'll say! A little skepticism might be in order. The Humboldt was 96-feet long, so taking the story at face value, we're talking about a 48-foot meteorite (i.e., a meteor that doesn't completely burn up in the atmosphere). Chief Engineer Burrill - or the Standard itself, for that matter -could not have survived the impact of such a meteorite, which, making some conservative assumptions, would have a mass of 2,000 tons with the explosive energy of 30 Hiroshima-size atomic bombs (see online version for calculation). Even allowing for considerable exaggeration, the story doesn't add up. For instance, a mere three-foot meteorite carries the punch of some 200 tons of TNT.
According to the story, witnesses "... first heard a sort of singing noise, not unlike escaping steam." Now, conventional wisdom has long held that there's no physical mechanism by which meteors can make a sound, and most astronomers have taken eyewitness accounts of whistling, rumbling and hissing meteors with a large grain of salt. But CW has been wrong before, and may - just possibly - be wrong in this case. In 1999, for instance, the BBC reported that a team of Croatian astronomers, while visiting Mongolia, had recorded sounds of Leonid meteors -- although their recording* is barely audible. UK astronomer Colin Keay offered this explanation for meteor sounds: "The twisting wake of the fireball might trap its magnetic field, creating very long radio waves which would travel to the ground below at the speed of light [resulting in] an audible sound at ground level by interacting with anything from a tree to someone's hairstyle or pair of spectacles." (I'd have settled for dilithium crystals ...)
Something happened here 81 years ago, but separating truth from fiction -- especially well-imagined fiction -- is beyond the scope of this column. One thing we know for sure is that a Huge Meteor/-ite did not plunge into Humboldt Bay 81 years ago, despite the headline. Perhaps a reader has more information?
* news.bbc.co.uk/2/hi/science/nature/321596.stm has a link to the sound file.
Barry Evans (firstname.lastname@example.org) hates to be the one to ruin a good story, honest!
Comparison between the reported meteorite and Hiroshima atomic bomb
48 ft meteorite = about 600 cm radius
Volume (4/3) π.r3 = (4/3) π.6003 = about 9 x 108 cm3
Meteorite density between 3 (chondite) and 8 (iron) gm/cm3, say 5 gm/cm3
Mass = (5/1000) (9 x 108) kg = about 4.5 x 106 kg (2,000 tons)
Meteorite impact velocity between 10 and 70 km/sec, say 20 km/sec = 20,000 m/s
Kinetic energy = mv2 = (4.5 x 106) (20,0002) kg.m2/s2 = 1.8 x 1015 kg.m2/s2
KE in joules = 1.8 x 1015 kg.2/s2 (joule = kg.m2/s2)
1 ton TNT equivalent to about 4 x 109 joules
48 ft. meteorite with density 5 gm/cm3 impacting at 20 km/sec is equivalent to
(1.8 x 1015) / (4 x 109) = 450,000 tons of TNT
Hiroshima = about 15,000 tons TNT
So meteorite would have been equivalent to 30 Hiroshima atomic bombs.