Nav: Home

A better way to learn if alien planets have the right stuff

August 24, 2016

New Haven, Conn. - A new method for analyzing the chemical composition of stars may help scientists winnow the search for Earth 2.0.

Yale University researchers Debra Fischer and John Michael Brewer, in a new study that will appear in the Astrophysical Journal, describe a computational modeling technique that 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 Fischer, a Yale professor of astronomy. "Our field is very focused on finding Earth 2.0, and anything we can do to narrow the search is helpful."

Lead author Brewer, a postdoctoral researcher at Yale, has used the technique previously to determine temperature, surface gravity, rotational speed, and chemical composition information for 1,600 stars, based on 15 elements found within those stars. The new study looks at roughly 800 stars, focusing on their ratio of carbon to oxygen, and magnesium to silicon.

Brewer explained that understanding the makeup of stars helps researchers understand the planets in orbit around them. "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."

For instance, the new study shows that in many cases, carbon isn't 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% of the stars in the study have magnesium/silicon ratios that would produce Earth-like compositions; 40% 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."

In addition to helping identify planets more like Earth, the study sheds light on the occurrence of "diamond" planets -- planets with a high carbon-to-oxygen abundance. Brewer and Fischer found that it is "exceedingly rare" to find a star with a carbon/oxygen ratio high enough to produce a diamond planet. In fact, the new data reveals that the star of the much discussed diamond planet, 55 Cancri e, does not have a high enough carbon/oxygen ratio to support its nickname.

"They're even more rare than we thought a few years ago," Fischer said. "Diamond planets truly are the most precious."
-end-


Yale University

Related Planets Articles:

Ultracool dwarf and the 7 planets
Astronomers have found a system of seven Earth-sized planets just 40 light-years away.
ALMA measures size of seeds of planets
Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA), have for the first time, achieved a precise size measurement of small dust particles around a young star through radio-wave polarization.
Origin of minor planets' rings revealed
A team of researchers has clarified the origin of the rings recently discovered around two minor planets known as centaurs, and their results suggest the existence of rings around other centaurs.
Are planets setting the sun's pace?
The sun's activity is determined by the sun's magnetic field.
A better way to learn if alien planets have the right stuff
A new method for analyzing the chemical composition of stars may help scientists winnow the search for Earth 2.0.
A new Goldilocks for habitable planets
The search for habitable, alien worlds needs to make room for a second 'Goldilocks,' according to a Yale University researcher.
Probing giant planets' dark hydrogen
Hydrogen is the most-abundant element in the universe, but there is still so much we have to learn about it.
Universe's first life might have been born on carbon planets
Our Earth consists of silicate rocks and an iron core with a thin veneer of water and life.
Number of habitable planets could be limited by stifling atmospheres
New research has revealed that fewer than predicted planets may be capable of harbouring life because their atmospheres keep them too hot.
Footprints of baby planets in a gas disk
A new analysis of the ALMA data for a young star HL Tauri provides yet more firm evidence of baby planets around the star.

Related Planets Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...