The map above shows the distribution of more than 3,000 bolides detected by the GLMs aboard GOES-16 and GOES-17 between July 2017 and January 2022. Smith and his team described their work in the journal Icarus in November 2021. Their goal was to build a publicly available database of bolide events and their light curves-the trajectories and intensity of the light streaks they left across the sky. Two years ago, Smith and colleagues began developing and training a machine learning algorithm to have computers automatically detect bolides in GLM data. It can detect bolides from about 4 inches (1 decimeter) up to about 9 feet (3 meters) wide. The GLM samples transient light at a rate of 500 frames per second. In 2018, astronomer Peter Jenniskens (also of SETI and NASA Ames) and colleagues showed that the Geostationary Lightning Mapper (GLM) aboard NOAA’s GOES-16 weather satellite could be used to observe the fleeting flashes of bolides. Recently, scientists figured out that they have such a detector, even though it was not designed to detect space rocks hurtling through the atmosphere. “Bolide explosions are also very quick, typically lasting just a fraction of a second, so very fast detectors are needed.” Smith, a data scientist at the SETI Institute and the principal investigator on a cooperative project with the Asteroid Threat Assessment Project at NASA’s Ames Research Center. “Bolides are rare and, due to the limited observational areas of ground-based systems, very few bolides are detected from the ground-perhaps only a couple a year,” said Jeffrey C. Yet most bolides enter the atmosphere over the 70 percent of Earth that is covered by ocean. While there are a few space-based bolide detection programs around the world, the majority are ground-based-including the NASA Meteorite Tracking and Recovery Network and the NASA All-Sky Fireball Network. When it exploded in the atmosphere, it released the energy equivalent of a 30-ton TNT blast that was recorded by detectors at an infrasound station near Pittsburgh. The meteor was estimated to be half a ton, a yard wide, and traveling about 45,000 miles per hour. The culprit was later confirmed by NASA Meteor Watch: it was a bolide, a very large, bright fireball (a meteor brighter than Venus). Allegheny County quickly acknowledged the event, noting that it wasn’t an earthquake or thunder and admitting “we have no explanation for the reports.” Early on New Year’s Day, many local residents heard a loud boom and felt the ground shake, prompting calls to 911. The new year began with a bang in Pittsburgh, Pennsylvania.
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