habitable zone tagged posts

Giant Planets Cast a Deadly Pall

Giant exoplanet in transit
Artist rendering of a gas-giant exoplanet transiting across the face of its star. (ESA/C. Carreau/NASA)

How they can prevent life in other planetary systems. Giant gas planets can be agents of chaos, ensuring nothing lives on their Earth-like neighbors around other stars. New studies show, in some planetary systems, the giants tend to kick smaller planets out of orbit and wreak havoc on their climates.

Jupiter, by far the biggest planet in our solar system, plays an important protective role. Its enormous gravitational field deflects comets and asteroids that might otherwise hit Earth, helping create a stable environment for life. However, giant planets elsewhere in the universe do not necessarily protect life on their smaller, rocky planet neighbors.

A new Astronomical Journal p...

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Ultracool Dwarf Binary Stars Break Records

The researchers say that by studying similar star systems, we can learn more about potentially habitable planets beyond Earth. Ultracool dwarfs are much fainter and dimmer than the sun, so any worlds with liquid water on their surfaces — a crucial ingredient to form and sustain life — would need to be much closer to the star. NASA/JPL Caltech image

Astrophysicists discover the closest and oldest ultracool dwarf binary ever observed. Northwestern University and the University of California San Diego (UC San Diego) astrophysicists have discovered the tightest ultracool dwarf binary system ever observed.

The two stars are so close that it takes them less than one Earth day to revolve around each other. In other words, each star’s “year” lasts just 17 hours.

The newly discovered ...

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Ocean World: Rocky Exoplanet has just Half the Mass of Venus

A team of astronomers have used the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile to shed new light on planets around a nearby star, L98-59, that resemble those in the inner Solar System. Amongst the findings are a planet with half the mass of Venus — the lightest exoplanet ever to be measured using the radial velocity technique — an ocean world, and a possible planet in the habitable zone.

“The planet in the habitable zone may have an atmosphere that could protect and support life,” says María Rosa Zapatero Osorio, an astronomer at the Centre for Astrobiology in Madrid, Spain, and one of the authors of the study published today in Astronomy & Astrophysics.

The results are an important step in the quest to find life on Earth-sized planets outside the...

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Earth-like Biospheres on other Planets may be Rare

An artistic representation of the potentially habitable planet Kepler 422-b (left), compared with Earth (right).
Credit
Ph03nix1986 / Wikimedia Commons
Licence type
Attribution-ShareAlike (CC BY-SA 4.0)

A new analysis of known exoplanets has revealed that Earth-like conditions on potentially habitable planets may be much rarer than previously thought. The work focuses on the conditions required for oxygen-based photosynthesis to develop on a planet, which would enable complex biospheres of the type found on Earth. The study is published today in Monthly Notices of the Royal Astronomical Society.

The number of confirmed planets in our own Milky Way galaxy now numbers into the thousands...

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