‘Devil Comet' discovery yields ‘strongest evidence yet' that comets transported water to Earth, scientists say

New York Post

a day ago

A comet named 'Devil' has revealed an important clue about the origin of water on Earth.
Researchers recently discovered that water on Comet 12P/Pons-Brooks, a rare galactic phenomenon known for its horn-like gas outbursts, has the same chemical signature as the water in Earth's oceans.
3 Comet 12P/Pons-Brooks — known as the 'Devil Comet' — is a rare galactic phenomenon the size of Mount Everest, known for its horn-like gas outbursts.
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This finding supports the long-standing theory that comets may have delivered water to Earth billions of years ago through massive impacts.
The new study, published in Nature Astronomy, marks a breakthrough in the search for our planet's H2O origins.
'Our new results provide the strongest evidence yet that at least some Halley-type comets carried water with the same isotopic signature as that found on Earth,' Martin Cordiner, a NASA astrophysicist who led the research, said in a statement.
Using two powerful telescopes — the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile and NASA's Infrared Telescope Facility (IRTF) in Hawaii — scientists studied the 'chemical fingerprint' of the water in the Mount Everest-sized comet.
Specifically, they examined the ratio of deuterium, a heavy form of hydrogen, to ordinary hydrogen — known as the D/H ratio — which helps scientists trace the chemical evolution of water.
3 New research showed that water on the 'Devil Comet' has the same chemical signature as the water in Earth's oceans.
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The lower the D/H ratio, the more Earth-like the water is.
In the case of 12P/Pons-Brooks, the comet's D/H ratio was almost identical to that of Earth's water — something never before seen in this class of comets.
'Devil' comets like 12P/Pons-Brooks are known as Halley-type comets, referring to the historic Halley's Comet. They orbit the Sun every 20 to 200 years and are considered ancient leftovers from the early solar system.
Until now, most comets studied had different D/H ratios than Earth's water, making it hard to prove that comets brought water here.
Cordiner explained that this discovery is the strongest, 'supporting the idea that comets could have helped make our planet habitable.'
This is also the first time scientists have mapped both regular water (H₂O) and 'heavy' water (HDO) around a comet in such detail. By doing so, they could confirm that water was derived from the depths of the comet's core.
'By mapping both H2O and HDO in the comet's coma, we can tell if these gases are coming from the frozen ices within the solid body of the nucleus, rather than forming from chemistry or other processes in the gas coma,' NASA's Stefanie Milam, a co-author of the study, said in a statement.
3 In the case of 12P/Pons-Brooks, the comet's D/H ratio was almost identical to that of Earth's water — something never before seen in this class of comets.
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Earth is believed to have formed mostly dry, with water arriving later. Scientists have long theorized that water came from icy objects crashing into our young planet.
This latest research supports that theory and shows that at least some comets carried the right kind of water.
The 'Devil Comet' was last visible from Earth this spring when it returned for 1st time in 71 years during the April eclipse.