Exoplanets Archives

September 19, 2024September 19, 2024 by Brian Koberlein

Exoplanets Could be Hiding Their Atmospheres

Illustration of the tidally locked world TRAPPIST-1f. Credit: NASA/JPL-Caltech

Most of the exoplanets we’ve discovered orbit red dwarf stars. This isn’t because red dwarfs are somehow special, simply that they are common. About 75% of the stars in the Milky Way are red dwarfs, so you would expect red dwarf planets to be the most abundant. This also means that most habitable worlds are going to orbit these small, cool stars, and that has some significant consequences for our search for life.

September 9, 2024September 9, 2024 by Mark Thompson

Iron Winds are Blowing on WASP-76 b

WASP-76 b has been the subject of numerous studies since its discovery in 2013. The temperature there reaches 2,400 degrees Celsius. © Tania Cunha (Planetário do Porto - Centro Ciência Viva/Instituto de Astrofísica e Ciências do Espaço)

Exoplanets have been discovered with a wide range of environmental conditions. WASP-76b is one of the most extreme with a dayside temperature of over 2,000 degrees. A team of researchers have found that it’s even more bizarre than first thought! It’s tidally locked to its host star so intense winds encircle the planet. They contain high quantities of iron atoms that stream from the lower to upper layers around the atmosphere.

September 7, 2024September 7, 2024 by Carolyn Collins Petersen

There’s More Water Inside Planets Than We Thought

Planets with magma oceans like this one, GJ 1214b, could have most of their water beneath the surface, deep in their interiors. Image: NASA/JPL-Caltech/R. Hurt

When you walk across your lawn or down the street, you move on the surface of a surprisingly layered world. Some of those layers are rock, others are molten. A surprising amount of water is mixed into those layers, as well. It turns out that most planets have more of it “deep down” than we imagined.

August 31, 2024August 31, 2024 by Mark Thompson

By Watching the Sun, Astronomers are Learning More about Exoplanets

Illustration of the Sun seen from Mercury

Watching the Olympics recently and the amazing effort of the hammer throwers was a wonderful demonstration of the radial velocity method that astronomers use to detect exoplanets. As the hammer spins around the athlete, their body and head bobs back and forth as the weight from the hammer tugs upon them. In the same way we can detect the wobble of a star from the gravity of planets in orbit. Local variations in the stars can add noise to the data but a team of researchers have been studying the Sun to help next-generation telescopes detect more Earth-like planets.

August 30, 2024August 30, 2024 by Evan Gough

How Vegetation Could Impact the Climate of Exoplanets

Image of Earth from 2020, over the South Pacific Ocean from the EPIC camera on the DSCOVR satellite. Many things affect Earth's albedo, including clouds, snow cover, and vegetation. How does exoplanet vegetation affect albedo and climate? Credit: NASA/NOAA

The term ‘habitable zone’ is a broad definition that serves a purpose in our age of exoplanet discovery. But the more we learn about exoplanets, the more we need a more nuanced definition of habitable.

New research shows that vegetation can enlarge the habitable zone on any exoplanets that host plant life.

August 26, 2024August 26, 2024 by Mark Thompson

X-Ray Telescopes Could Study Exoplanets Too

Exoplanets are often discovered using the transit method (over three quarters of those discovered have been found this way.) The same transit technique can be used to study them, often revealing detail about their atmosphere. The observations are typically made in visible light or infrared but a new paper suggests X-rays may be useful too. Stellar wind interactions with the planet’s atmosphere for example would lead to X-ray emissions revealing information about the atmosphere. As we further our exploration of exoplanets we develop our understanding of our own Solar System and ultimately, the origins of life in the Universe.

August 19, 2024August 19, 2024 by Laurence Tognetti

Earth-like exoplanets might be in short supply for the Habitable Worlds Observatory

How common are Earth-like exoplanets—also called exo-Earths—and which exoplanetary systems should we target to find them? This is what a recently submitted study hopes to address as a team of researchers investigated potential targets for the planned Habitable Worlds Observatory (HWO), which was recommended during the Decadal Survey on Astronomy and Astrophysics 2020 (Astro2020) and is slated to launch in the 2040s. Most notably, HWO will use the direct imaging method to identify exo-Earths, and this study holds the potential to create a more scientifically cost-effective approach for identifying and studying exoplanets.

August 16, 2024August 16, 2024 by Evan Gough

Ocean Salinity Affects Earth’s Climate. How About on Exoplanets?

There’s a link between Earth’s ocean salinity and its climate. Salinity can have a dramatic effect on the climate of any Earth-like planet orbiting a Sun-like star. But what about exoplanets around M-dwarfs?

August 10, 2024August 11, 2024 by Laurence Tognetti

Good Thing We Found this Earth-Sized Planet Now. It’s About to Be Destroyed

Illustration of an Earth-sized world. (Credit: NASA/JPL-Caltech/Robert Hurt)

Astronomers have confirmed the existence of exoplanets with extremely small orbits around their stars. But what about exoplanets that get close enough to be devoured by their star, and what if it’s an Earth-sized exoplanet? This is what a recent study accepted to AAS Journals hopes to address as an international team of more than 50 researchers investigated an Earth-sized exoplanet with an orbital period of only 5.7 hours, known as “ultra-short-period” (USP) exoplanets, that could eventually experience what’s known as tidal disruption, resulting in its devourment by its star. This study holds the potential to help researchers better understand the processes responsible for this, along with continuing to challenge our understanding of exoplanetary architectures, as well.

August 5, 2024August 5, 2024 by Mark Thompson

Astronomers See Planets Forming Around Binary Stars

Artist's illustration of binary star planet formation. Credit: S. Dagnello, NSF/AUI/NRAO

Over 5,000 exoplanets have been discovered around distant star systems. Protoplanetary disks have been discovered too and it’s these, out of which all planetary systems form. Such disks have recently been found in two binary star systems. The stellar components in one have a separation of 14 astronomical units (the average distance between the Earth and Sun is one astronomical unit) and the other system has a separation of 22 astronomical units. Studying systems like these allow us to see how the stars of a binary system interact and how they can distort protoplanetary disks.