2 months ago
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The supposed interstellar fireball detected over the Pacific Ocean in 2014 probably came from within our solar system, according to new statistical modeling of the meteor and others similar to it.
The new study also concludes that debris from the fireball would not have survived passage through Earth's atmosphere, meaning that the claimed recovery of fragments from it must have a different, more mundane origin.
These results come from an international team of European and U.S. astronomers led by Maria Hajduková of the Astronomical Institute of the Slovak Academy of Sciences. By scrutinizing the altitude and velocity data for the 2014 fireball, plus hundreds of others in NASA's Center for Near Earth Object Studies (CNEOS) fireball catalog, they found that the information given about the fireballs does not include the error range for each measurement. An error range is the level of imprecision of any scientific observation. The problem, explained Hajduková's team, is that this imprecision can make meteors native to our solar system seem as though they have come from interstellar space.
Fireballs are the brightest of meteors, and are seen from the ground as a falling ball of flame shooting across the sky before fading. Most "shooting stars" are the products of tiny grains of dust a millimeter across or smaller, but a fireball might be produced by a stone-sized meteoroid. (A meteoroid is what these objects are called while they are in space; when we see them falling through the atmosphere, we call them a meteor, and any that survive that fall to reach the ground are referred to as meteorites.)
Related: Interstellar meteor fragments found? Harvard astronomer's claim sparks debate, criticism
Harvard astronomer Avi Loeb, who is no stranger to controversial claims about interstellar objects, and his Harvard colleague Amir Siraj argue that a fireball witnessed over Papua New Guinea on Jan. 8, 2014 and detected by U.S. Department of Defense sensors likely came from beyond our solar system. So strongly did they believe this that they even mounted a private, cryptocurrency-funded expedition to the Pacific to trawl the ocean floor in search of debris from the fireball. They found "spherules" that they claim have a composition that marks them out as interstellar in nature. However, independent analyses of the spherules by Steven Desch of Arizona State University and Alan Jackson of Towson University in Maryland suggest that they are nothing more than industrial waste from the burning of coal.
Now Hajduková's team, of which Desch and Jackson are a part, have also quantitatively shown that the fireball was very unlikely to have been interstellar in nature, and instead most likely was a native of our solar system.
Loeb and Siraj had staked their interstellar claim on data in the CNEOS catalog that appears to show that the fireball was traveling at 27.8 miles (44.8 kilometers) per second relative to the sun when it entered Earth's atmosphere. This is greater than the solar system's escape velocity, which varies with distance from the sun but at Ear...
