Life Might Be Easiest to Find on Planets that Match an Earlier Earth

Artist's impression of the "pale orange dot" - what early Earth would have looked like. Credit: NASA/Goddard Space Flight Center/Francis Reddy

We’re inching closer and closer to reliably detecting biosignatures on distant planets. Much of the focus is on determining which chemicals indicate life’s presence.

But life can also create free energy in a system, and excess energy can create chemical disequilibrium. That’s what happened on Earth when life got going. Could chemical disequilibrium be a biosignature?

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This is a First. An Exoplanet in a Polar Circumbinary Disc Surrounding Two Stars.

This illustration shows a binary star surrounded by a thick disc of material in a polar orbit. Copyright and credit: University of Warwick/Mark Garlick

We live in an age of exoplanet discovery. One thing we’ve learned is not to be surprised by the kinds of exoplanets we keep discovering. We’ve discovered planets where it might rain glass or even iron, planets that are the rocky core remnants of gas giants stripped of their atmospheres, and drifting rogue planets untethered to any star.

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TESS Finds Eight More Super-Earths

Artist’s impression of a Super-Earth orbiting a Sun-like star. Super-Earths are more massive than Earth yet lighter than ice giants like Neptune and Uranus, and can be made of gas, rock or a combination of both. They are between twice the size of Earth and up to 10 times its mass. Image Credit: ESO

NASA’s Kepler spacecraft has discovered most of the confirmed exoplanets that we know of. But its successor, TESS (Transiting Exoplanet Survey Satellite), is catching up. New research announces the validation of eight more TESS candidates, and they’re all Super-Earths.

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Exo-Jupiters’ Commonality and Exclusivity Highlighted in Two New Studies

Image of Jupiter taken by NASA’s Juno spacecraft. Two recent studies explore how Exo-Jupiters might be more common than previously thought along with entire systems being exclusively comprised of them. (Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)

A pair of recent studies conduct in-depth analyses of Jupiter-sized exoplanets, also known as Exo-Jupiters, and were published in Nature Communications and The Astronomical Journal, respectively. The study published in Nature Communications was conducted by an international team of researchers and examines how Exo-Jupiters could be more common than previously thought, while the study published in The Astronomical Journal was conducted by one researcher and examines exoplanetary system, HD 141399, and how it is comprised entirely of Exo-Jupiters with no additional planets.

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Old Data from Kepler Turns Up A System with Seven Planets

Artist’s concept of Kepler-385, the seven-planet system revealed in a new catalog of planet candidates discovered by NASA’s Kepler space telescope. Image Credit: NASA/Daniel Rutter

NASA’s Kepler mission ended in 2018 after more than nine years of fruitful planet-hunting. The space telescope discovered thousands of planets, many of which bear its name. But it also generated an enormous amount of data that exoplanet scientists are still analyzing.

Now, a team of researchers has shed new light on a seven-planet system in Kepler’s ocean of data.

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White Dwarfs Could Support Life. So Where are All Their Planets?

Artist's view of old white dwarfs surrounded by planetary debris. Credit: University of Warwick/Dr Mark Garlick

Astronomers have found plenty of white dwarf stars surrounded by debris disks. Those disks are the remains of planets destroyed by the star as it evolved. But they’ve found one intact Jupiter-mass planet orbiting a white dwarf.

Are there more white dwarf planets? Can terrestrial, Earth-like planets exist around white dwarfs?

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Three Planets Around this Sunlike Star are Doomed. Doomed!

A distant Sun-like star will leave the main sequence behind, ending its life of fusion. Then it'll expand into a red giant, totally destroying its four planets. Image Credit: fsgregs Creative Commons Attribution-Share Alike 3.0 Unported

According to new research we can start writing the eulogy for four exoplanets around a Sun-like star about 57 light years away. But there’s no hurry; we have about one billion years before the star becomes a red giant and starts to destroy them.

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JWST Searches for Planets in the Fomalhaut System

This image shows Fomalhaut, the star around which the newly discovered planet orbits. Fomalhaut is much hotter than our Sun, 15 times as bright, and lies 25 light-years from Earth. It is blazing through hydrogen at such a furious rate that it will burn out in only one billion years, 10% the lifespan of our star. The field of view is 2.7 x 2.9 degrees.

The Fomalhaut system is nearby in astronomical terms, and it’s also one of the brightest stars in the night sky. That means astronomers have studied it intensely over the years. Now that we have the powerful James Webb Space Telescope the observations have intensified.

The Fomalhaut system has a confounding and complex dusty disk, including a dusty blob. The blob has been the subject of an ongoing debate in astronomy. Can the JWST see through its complexity and find answers to the systems unanswered questions?

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Want to Find Life? Compare a Planet to its Neighbors

Earth compared to the exoplanet Kepler-186f. Credit: NASA's Goddard Space Flight Center

With thousands of known exoplanets and tens of thousands likely to be discovered in the coming decades, it could be only a matter of time before we discover a planet with life. The trick is proving it. So far the focus has been on observing the atmospheric composition of exoplanets, looking for molecular biosignatures that would indicate the presence of life. But this can be difficult since many of the molecules produced by life on Earth could also be produced by geologic processes. A new study argues that a better approach would be to compare the atmospheric composition of a potentially habitable world with those of other planets in the star system.

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Misaligned Binary Star Systems are Rogue Planet Factories

Artist's impression of a rogue planet. Credit: ESO/L. Calçada/P. Delorme/R. Saito/VVV Consortium

Most of the planets in the Universe orbit a star. They are part of a system of planets, similar to our own solar system. But a few planets drift alone in the cosmos. For whatever reason, be it a near collision or slow gravitational perturbations that destabilize its orbit, these planets are cast out of their star system and sent adrift. These rogue planets are notoriously challenging to find, but as we start to discover them we’re finding they are a bit more common than we’d thought. Now a new study posits a reason why.

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