New method to narrow down search for Earth 2.0

A new method for analysing the chemical composition of stars -- their carbon-to-oxygen and magnesium-to-silicon ratios -- may help scientists find alien planets with the right stuff for sustaining life, a study says.

The computational modeling technique developed by Yale University researcher gives a clearer sense of the chemistry of stars, revealing the conditions present when their planets formed.

The system creates a new way to assess the habitability and biological evolution possibilities of planets outside our solar system.

"This is a very useful, easy diagnostic to tell whether that pale blue dot you see is more similar to Venus or the Earth," said Debra Fischer, Professor of Astronomy.

"Our field is very focused on finding Earth 2.0, and anything we can do to narrow the search is helpful," Fischer noted.

The scientists looked at roughly 800 stars, focusing on their ratio of carbon to oxygen, and magnesium to silicon.

Understanding the makeup of stars helps researchers understand the planets in orbit around them, lead author John Michael Brewer explained.

"We're getting a look at the primordial materials that made these planets," he said.

"Knowing what materials they started with leads to so much else," Brewer noted.

The study showed that in many cases, carbon is not the driving force in planetary composition.

Brewer found that if a star has a carbon/oxygen ratio similar to or lower than that of our own Sun, its planets have mineralogy dominated by the magnesium/silicon ratio.

About 60 per cent of the stars in the study have magnesium/silicon ratios that would produce Earth-like compositions and 40 per cent of the stars have silicate-heavy interiors.

"This will have a profound impact on determining habitability," Brewer said.

"It will help us make better inferences about which planets will be ones where life like ours can form," Brewer noted.

The study will appear in a forthcoming issue of the Astrophysical Journal.

--IANS

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