Date:

Paired with super telescopes, model Earths guide hunt for life

Cornell University astronomers have created five models representing key points from our planet’s evolution, like chemical snapshots through Earth’s own geologic epochs.

The models will be spectral templates for astronomers to use in the approaching new era of powerful telescopes, and in the hunt for Earth-like planets in distant solar systems.

“These new generation of space- and ground-based telescopes coupled with our models will allow us to identify planets like our Earth out to about 50 to 100 light-years away,” said Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute.

For the research and model development, Kaltenegger, doctoral student Jack Madden and Zifan Lin authored “High-Resolution Transmission Spectra of Earth through Geological Time,” published in Astrophysical Journal Letters.

- Advertisement -

“Using our own Earth as the key, we modeled five distinct Earth epochs to provide a template for how we can characterize a potential exo-Earth – from a young, prebiotic Earth to our modern world,” she said. “The models also allow us to explore at what point in Earth’s evolution a distant observer could identify life on the universe’s ‘pale blue dots’ and other worlds like them.”

Kaltenegger and her team created atmospheric models that match the Earth of 3.9 billion years ago, a prebiotic Earth, when carbon dioxide densely cloaked the young planet. A second throwback model chemically depicts a planet free of oxygen, an anoxic Earth, going back 3.5 billion years. Three other models reveal the rise of oxygen in the atmosphere from a 0.2% concentration to modern-day levels of 21%.

“Our Earth and the air we breathe have changed drastically since Earth formed 4.5 billions years ago,” Kaltenegger said, “and for the first time, this paper addresses how astronomers trying to find worlds like ours, could spot young to modern Earth-like planets in transit, using our own Earth’s history as a template.”

In Earth’s history, the timeline of the rise of oxygen and its abundancy is not clear, Kaltenegger said. But, if astronomers can find exoplanets with nearly 1% of Earth’s current oxygen levels, those scientists will begin to find emerging biology, ozone and methane – and can match it to ages of the Earth templates.

“Our transmission spectra show atmospheric features, which would show a remote observer that Earth had a biosphere as early as about 2 billion years ago,” Kaltenegger said.

Using forthcoming telescopes like NASA’s James Webb Space Telescope, scheduled to launch in March 2021, or the Extremely Large Telescope in Antofagasta, Chile, scheduled for first light in 2025, astronomers could watch as an exoplanet transits in front of its host star, revealing the planet’s atmosphere.

“Once the exoplanet transits and blocks out part of its host star, we can decipher its atmospheric spectral signatures,” Kaltenegger said. “Using Earth’s geologic history as a key, we can more easily spot the chemical signs of life on the distant exoplanets.”

CORNELL UNIVERSITY

Header Image – NASA’s James Webb Space Telescope – Credit : NASA/Chris Gunn

- Advertisement -
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.

Mobile Application

spot_img

Related Articles

Researchers find that Żagań-Lutnia5 is an Iron Age stronghold

Archaeologists have conducted a ground penetrating radar (GPR) survey of Żagań-Lutnia5, revealing that the monument is an Iron Age stronghold.

Rare copper dagger found in Polish forest

A rare copper dagger from over 4,000-years-ago has been discovered in the forests near Korzenica, southeastern Poland.

Neanderthals created stone tools held together by a multi-component adhesive

A new study published in the journal Science Advances has found evidence of Neanderthals creating stone tools that are held together using a multi-component adhesive.

Roman funerary altar found partially buried in Torre river

Archaeologists have recovered a Roman funerary altar which was found partially buried in the Torree river in the municipality of San Vito al Torre, Italy.

Post-medieval township discovered in Scottish forest

Archaeologists have uncovered the remains of a pre-medieval township in the Glen Brittle Forest on the Isle of Skye.

Geophysical study finds evidence of “labyrinth” buried beneath Mitla

A geophysical study has found underground structures and tunnels beneath Mitla – The Zapotec “Place of the Dead”

Discovery of a Romanesque religious structure rewrites history of Frauenchiemsee

Archaeologists from the Bavarian State Office for Monument Preservation have announced the discovery of a Romanesque religious structure on the island of Frauenchiemsee, the second largest of the three islands in Chiemsee, Germany.

Ring discovery suggests a previously unknown princely family in Southwest Jutland

A ring discovered in Southwest Jutland, Denmark, suggests a previously unknown princely family who had strong connections with the rulers of France.