Meteor causes sonic boom over East Boston
Many New Englanders were startled by a meteor breaking the sound barrier on May 30, likening the noise to an explosion over their heads
Early in the afternoon on May 30, people in Boston and surrounding areas of greater New England as far away as Rhode Island were startled by what sounded like a large explosion. The noise sounded as if “someone dropped a box or broke down a bedframe,” recalled Esther Jung ’28.
For MIT graduates and commencement volunteers still on campus, the sound could have easily been mistaken for the sounds of summer move out. But as people across Massachusetts took to social media to ask if others had heard the same sound, it became increasingly clear that this noise was not caused by a box, a bomb, or a tree falling on a house. While there was a passing storm system, meteorologists didn’t see signs of thunder and lightning on satellite data. Some people also reported shaking, but there was no evidence of seismic activity either. Later that evening, NASA announced that the sound heard was a sonic boom produced by a meteor exploding over northeastern Massachusetts.
Where did the meteor come from, and how did it get here?
The origins of the meteor have yet to be confirmed; however, a 2024 study by an international team of astronomers found that about the vast majority of meteors are created by asteroid collisions in the asteroid belt between Mars and Jupiter. More specifically, the study found that 80% of meteors come from only three families of asteroids in the asteroid belt, giving the fragments that end up on Earth very similar material compositions.
Assuming the same is true for our most recent cosmic visitor, scientists may have a good idea of what to look for if they try to locate the meteorites in Cape Cod. Namely, the three aforementioned asteroid families are made up of considerably magnetic materials, leading NASA to report that “these [magnetic meteorites] are within reach of a 100’ length of rope dangled off of a boat. In case anyone is interested in such factoids.” As of writing, no one has reported recovering any meteorites from Cape Cod with this method.
That same NASA report estimated that the meteor weighed 5,600 kilograms upon reaching Earth, with about 10% of that mass surviving as meteorites when it reached the Cape. (Meteors are reclassified as meteorites when they reach the Earth’s surface.) To illustrate, the meteor was originally as massive as a mid-sized African elephant; intense friction with the air in the atmosphere whittled it down to the mass of a small grand piano. (Compared to other meteors that Earth has encountered, this one was relatively small. Tunguska, which caused the most massive meteor blast in recorded history after striking Russia in 1908, is estimated to have weighed 3–5 billion kilograms).
As many New Englanders discovered on May 30, the meteor’s interaction with Earth’s atmosphere did a lot more than reduce its mass by 90%. On June 3, NASA deduced that the meteor travelled through the atmosphere at over 18 kilometers per second (over 40,000 miles per hour). Objects travelling at high speeds end up putting immense pressure on the air in front of it. Once an object’s speed exceeds the speed of sound (about 0.34 kilometers per second, or 768 miles per hour, in dry air at 68°F), the rapid buildup of pressure in front of the object results in a single shockwave, which can be heard as a thunderous “sonic boom.”
Sonic booms are far from a recent phenomenon; in fact, humans have been developing aircraft capable of breaking the sound barrier for decades. The first supersonic aircraft, the Bell X-1 of the United States Air Force, took flight in 1947 and achieved a top speed 1.06 times faster than sound. Planes have become considerably faster since the Bell X-1 (in 2004, NASA’s unmanned X-43 plane traveled at 9.6 times the speed of sound), but most commercial flights today travel slightly slower than the speed of sound to avoid noise disruptions for people living below those flights’ paths.
Unfortunately for many New Englanders, the May 30 meteor had no such reservations. It soared through the air at over 52 times the speed of sound, resulting in the explosive boom heard all across the region.