Elliptical Orbits Could be Essential to the Habitability of Rocky Planets

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)
This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

A seismic shift occurred in astronomy during the Scientific Revolution, beginning with 16th-century polymath Copernicus and his proposal that the Earth revolved around the Sun. By the 17th century, famed engineer and astronomer Galileo Galilei refined Copernicus’ heliocentric model using observations made with telescopes he built himself. However, it was not until Kepler’s observations that the planets followed elliptical orbits around the Sun (rather than circular orbits) that astronomical models matched observations of the heavens completely.

As it turns out, this very quirk of orbital mechanics may be essential to the emergence of life on planets like Earth. That was the hypothesis put forth in a recent study by a team of astronomers led by the University of Leeds. According to their work, orbital eccentricity (how much a planet’s orbit deviates from a circle) can influence a planet’s climate response, which could have a profound effect on its potential habitability. These findings could be significant for exoplanet researchers as they continue to search for Earth-like planets that could support life.

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Scientists Simulate the Climate of Arrakis. It Turns Out Dune is a Pretty Realistic Exoplanet

Is the planet Arrakis realistic? Image Credit: By The Central Intelligence Agency - The World Factbook - Algeria, Public Domain, https://commons.wikimedia.org/w/index.php?curid=29196928

Science fiction author Frank Herbert is renowned for the richly-detailed worlds he created. None of his work is more well-known than “Dune,” which took him six years to complete. Like his other work, Dune is full of detail, including the description of planet Dune, or as the Fremen call it, Arrakis.

Dune is an unforgiving desert world that suffers powerful dust storms and has no rainfall. Scientists who specialize in modelling climates set out to see how realistic Dune is compared to exoplanets. Their conclusion?

Frank Herbert did a great job, considering he created Dune in the 1960s.

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A new Climate Model Suggests That Venus Never had Oceans

Observations suggest Venus may have had water oceans in its distant past. A land-ocean pattern like that above was used in a climate model to show how storm clouds could have shielded ancient Venus from strong sunlight and made the planet habitable. Credits: NASA

Thanks to evidence provided by missions like NASA’s Magellan spacecraft, scientists have theorized that Venus likely experienced a catastrophic resurfacing event about 500 million years ago (give or take 200 Mya). This is believed to be the reason why Venus is such a hellish place today, with an atmosphere that is 92 times as dense as Earth’s, predominantly composed of carbon dioxide (CO2), and temperatures hot enough to melt lead.

The question of what Venus was like before this event took place – particularly, whether or not it had oceans – has been the subject of debate ever since. While many believe that Venus’s surface was covered in large bodies of water, a recent study has contradicted this claim. Using a state-of-the-art climate model, a team of French researchers has developed an alternative scenario of how Venus evolved to become what it is today.

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NASA Supercomputer Simulates the Weather on Mars

A screenshot of a NASA simulation of Martian water-ice clouds. Image Credit: NASA/Ames Research Center/D. Ellsworth

The Martian atmosphere is a lot different than Earth’s. It’s over 95% carbon dioxide, and contains only trace amounts of oxygen and water vapor. But that trace amount of water vapor still plays a pronounced role in the climate.

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