There are some unusual things about the meteorite that exploded like 300 tons of TNT over the East Coast on Saturday, according to NASA. In a Wednesday update on the meteor, the space agency revealed there are still questions lingering about it.
NASA noted that eyewitnesses in New England via the American Meteor Society and the National Oceanic and Atmospheric Administration saw a bright fireball accompanied by a loud noise on Saturday at around 2 p.m. ET. It said the meteor appeared to have fragmented at an altitude of 40 miles over northeast Massachusetts and southeast New Hampshire.
Meteorites, for reference, are solid pieces of debris from space objects like comets, asteroids and meteoroids that make their way through our atmosphere. Objects from space become meteors when they break through the atmosphere and turn into fireballs due to friction, pressure and chemicals. By the time they reach the surface of the Earth, these meteors typically break into small fragments called meteorites.
“The energy released at breakup is estimated to be equivalent to about 300 tons of TNT, which accounts for the loud noise,” NASA said in an X post about the recent meteor. In a follow-up post, the space agency said it has a mass of 5.6 metric tons (similar to that of an elephant) and that it entered Earth’s atmosphere at roughly 42,000 miles per hour.
As it plummeted towards Earth, the meteor had a “very high altitude terminus” that was around double the typical recording, NASA said Wednesday. That’s where the first question comes in: was this due to a “high-ish infall velocity… and steep entry angle?” the space station wondered.
Another unusual thing about the meteor was its short total appearance time on radar. Usually, meteors appear on radar for eight to 10 minutes, while this one only appeared for about two minutes.
“This suggests that very few small pieces were produced,” NASA said.
There’s also the meteor’s size compared to the number of meteorites observed on radar. NASA said this is “a slope higher than any other radar-detected fall to date,” and that it “indicates a meteoroid with high mechanical strength.”
NASA’s big, lingering question about this meteor is about what it was made of. Stony meteorites are the most common, followed by stony-iron meteorites and iron meteorites.
So far, clues point to iron as a possible answer for this recent meteor. First, a meteorite density calculation from the Jormungandr2 model gave a value consistent with an iron meteorite. However, NASA noted that the calculation is “still experimental at this stage.”
Meteorites that did appear after the fireball was spotted all fell in the waters of Cape Cod Bay appeared to be “concentrated in the 100s of grams to kg range,” according to NASA. Since typical meteorites are in the 1-100kg range, that also adds to the evidence suggesting it was an iron meteorite.
“It is not clear if the overall radar reflectivity is consistent with an iron meteorite however,” NASA said Wednesday.
Another meteor was also spotted this Monday in the Midwest, NASA reported.
