A new study from Cardiff University suggests there may be a cosmic lack of phosphorus, a crucial ingredient for life.
This is a mosaic image, one of the largest ever taken by Hubble of the Crab Nebula, a 6-light-year-wide expanding remnant of a star’s supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans. Image credit: NASA / ESA / J. Hester / A. Loll, Arizona State University.
“Phosphorus is one of just six chemical elements on which Earth organisms depend, and it is crucial to the compound adenosine triphosphate, which cells use to store and transfer energy,” said study lead author Dr. Jane Greaves, from the School of Physics and Astronomy at Cardiff University.
“Astronomers have just started to pay attention to the cosmic origins of phosphorus and found quite a few surprises.”
“In particular, phosphorus is created in supernovae but the amounts seen so far don’t match our computer models.”
“We wondered what the implications were for life on other planets if unpredictable amounts of phosphorus are spat out into space and later used in the construction of new planets.”
Dr. Greaves and colleagues used the William Herschel Telescope to observe infrared light from phosphorus and iron in the Crab Nebula, a supernova remnant approximately 6,500 light-years away in the direction of the constellation of Taurus.
“This is only the second such study of phosphorus that has been made,” said Dr. Phil Cigan, also from the School of Physics and Astronomy at Cardiff University.
“The first looked at the Cassiopeia A supernova remnant, and so we are able to compare two different stellar explosions and see if they ejected different proportions of phosphorus and iron. The first element supports life, while the second is a major part of our planet’s core.”
A false color image of Cassiopeia A using observations from NASA’s Spitzer Space Telescope and Chandra X-ray Observatory as well as the NASA/ESA Hubble Space Telescope. Image credit: NASA / JPL-Caltech.
The team struggled with foggy nights at the telescope, back in November 2017, and is only just starting to get scientific results from a few hours of data.
“These are our preliminary results, which we extracted only in the last couple of weeks,” Dr. Cigan noted.
“But at least for the parts of the Crab Nebula we were able to observe so far, there seems to be much less phosphorus than in Cassiopeia A.”
“The two explosions seem to differ from each other, perhaps because Cassiopeia A results from the explosion of a rare super-massive star.”
“We’ve just asked for more telescope time to go back and check, in case we’ve missed some phosphorus-rich regions in the Crab Nebula.”
The team’s results suggest that material blown out into space could vary dramatically in chemical composition.
“The route to carrying phosphorus into new-born planets looks rather precarious,” Dr. Greaves said.
“We already think that only a few phosphorus-bearing minerals that came to the Earth — probably in meteorites — were reactive enough to get involved in making proto-biomolecules.”
“If phosphorus is sourced from supernovae, and then travels across space in meteoritic rocks, I’m wondering if a young planet could find itself lacking in reactive phosphorus because of where it was born? That is, it started off near the wrong kind of supernova? In that case, life might really struggle to get started out of phosphorus-poor chemistry, on another world otherwise similar to our own.”
The astronomers presented their results April 5 at the European Week of Astronomy and Space Science (EWASS) in Liverpool, UK.
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Jane Greaves. Phosphorus production in supernovae and meteorites: a path to life on Earth? EWASS 2018, abstract # 771
