Some Young Planets Are Flattened Smarties, not Spheres.

This image from supercomputer simulations shows how some exoplanets form as 'flattened Smarties' rather than spheres. It shows the same planet from the top (left) and the side (right.) The images are from supercomputer simulations of planetary formation. Image Credit: Fenton and Stamatellos 2024.

One of contemporary astronomy’s most pressing questions concerns planet formation. We can see more deeply than ever into very young solar systems where planets are taking shape in the disks around young stars. But our view is still clouded by all the gas and dust in these young systems.

The picture of planet formation just got cloudier with the discovery that some young planets are shaped like flattened candies rather than spheres.

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Atmospheres in the TRAPPIST-1 System Should be Long Gone

Illustration of the Trappist-1 system. Credit: NASA/JPL-Caltech

Trappist-1 is a fascinating exoplanetary system. Seven worlds orbiting a red dwarf star just 40 light-years away. All of the worlds are similar to Earth in mass and size, and 3 or 4 of them are potentially habitable. Imagine exploring a system of life-rich worlds within easy traveling distance of each other. It’s a wonderful dream, but as a new study shows it isn’t likely that life exists in the system. It’s more likely the planets are barren and stripped of their atmospheres.

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A Super-Earth (and Possible Earth-Sized) Exoplanet Found in the Habitable Zone

Artist depiction of the surface of a super-Earth orbiting a red dwarf. Credit: ESO/M. Kornmesser

Astronomers have found a new Super-Earth orbiting an M-dwarf (red dwarf) star about 137 light-years away. The planet is named TOI-715b, and it’s about 1.55 Earth’s radius and is inside the star’s habitable zone. There’s also another planetary candidate in the system. It’s Earth-sized, and if it’s confirmed, it will be the smallest habitable zone planet TESS has discovered so far.

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Webb Directly Images Two Planets Orbiting White Dwarfs

Artist's rendition of a white dwarf from the surface of an orbiting exoplanet. Astronomers have found two giant planet candidates orbiting two white dwarfs. More proof that giant planets can surve their stars' red giant phases. Image Credit: Madden/Cornell University

In several billion years, our Sun will become a white dwarf. What will happen to Jupiter and Saturn when the Sun transitions to become a stellar remnant? Life could go on, though the giant planets will likely drift further away from the Sun.

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Water Vapor Found in the Atmosphere of a Small Exoplanet

Artist's impression of GJ 9827 d, which is the smallest exoplanet ever found to potentially possess water in its atmosphere. (Credit: NASA, ESA, Leah Hustak and Ralf Crawford (STScI))

A recent study published in The Astrophysucal Journal Letters discusses the detection of water within the atmosphere of GJ 9827 d, which is a Neptune-like exoplanet located approximately 97 light-years from Earth, using NASA’s Hubble Space Telescope (HST), and is the smallest exoplanet to date where water has been detected in its atmosphere. This study was conducted by an international team of researchers and holds the potential to identify exoplanets throughout the Milky Way Galaxy which possess water within their atmospheres, along with highlighting the most accurate methods to identify the water, as well.

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Did We Find Exomoons or Not? The Question Lingers.

Does Kepler-1708b have an exomoon? Scientists disagree. Image Credit: NASA

Do exoplanets have exomoons? It would be extraordinary if they didn’t, but as with all things, we don’t know until we know. Astronomers thought they may have found exomoons several years ago around two exoplanets: Kepler-1625b and Kepler-1708b. Did they?

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Another Explanation for K2-18b? A Gas-Rich Mini-Neptune with No Habitable Surface

Artist depiction of the mini-Neptune K2-18 b. Credit: NASA, CSA, ESA, J. Olmstead (STScI), N. Madhusudhan (Cambridge University)

Exoplanet K2-18b is garnering a lot of attention. James Webb Space Telescope spectroscopy shows it has carbon and methane in its atmosphere. Those results, along with other observations, suggest the planet could be a long-hypothesized ‘Hycean World.’ But new research counters that.

Instead, the planet could be a gaseous mini-Neptune.

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Exoplanets: Why study them? What are the challenges? What can they teach us about finding life beyond Earth?

Credit: NASA/W. Stenzel

Universe Today has explored the importance of studying impact craters and planetary surfaces and what these scientific disciplines can teach us about finding life beyond Earth. We learned that impact craters are caused by massive rocks that can either create or destroy life, and planetary surfaces can help us better understand the geologic processes on other worlds, including the conditions necessary for life. Here, we will venture far beyond the confines of our solar system to the many stars that populate our Milky Way Galaxy and the worlds they orbit them, also known as exoplanets. We will discuss why astronomers study exoplanets, challenges of studying exoplanets, what exoplanets can teach us about finding life beyond Earth, and how upcoming students can pursue studying exoplanets, as well. So, why is it so important to study exoplanets?

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What Could the Extremely Large Telescope See at Proxima Centauri's Planet?

Artist’s impression of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri. The double star Alpha Centauri AB is visible to the upper right of Proxima itself. Credit: ESO

Proxima Centauri B is the closest exoplanet to Earth. It is an Earth-mass world right in the habitable zone of a red dwarf star just 4 light-years from Earth. It receives about 65% of the energy Earth gets from the Sun, and depending on its evolutionary history could have oceans of water and an atmosphere rich with oxygen. Our closest neighbor could harbor life, or it could be a dry rock, but is an excellent target in the search for alien life. There’s just one catch. Our usual methods for detecting biosignatures won’t work with Proxima Centauri B.

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Is K2-18b Covered in Oceans of Water or Oceans of Lava?

This illustration shows what exoplanet K2-18 b could look like based on science data. NASA’s James Webb Space Telescope examined the exoplanet and revealed the presence of carbon-bearing molecules. The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. But more extensive observations with the JWST are needed to understand its atmosphere with greater confidence. Image Credit: By Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)Science: Nikku Madhusudhan (IoA)

In the search for potentially life-supporting exoplanets, liquid water is the key indicator. Life on Earth requires liquid water, and scientists strongly believe the same is true elsewhere. But from a great distance, it’s difficult to tell what worlds have oceans of water. Some of them can have lava oceans instead, and getting the two confused is a barrier to understanding exoplanets, water, and habitability more clearly.

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