Exoplanets Archives

June 15, 2023June 15, 2023 by Carolyn Collins Petersen

A Planet So Hot Its Atmosphere Contains the Raw Material for Rocks

An artist's impression of WASP-76b, a planet with an atmosphere so hot it vaporizes metals. Courtesy: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva/Spaceengine/M. Zamani

In the annals of “strange new worlds”, the ultra-hot Jupiter planet WASP-76b ranks right up there as a very unusual place. There’s no surface, but it does have a massive, hot atmosphere. Temperatures average a raging 2000 C and rise up to 2400 C in one hemisphere. That’s hot enough for mineral and rock-forming elements like calcium, nickel, and magnesium to get vaporized and float around in that thick blanket of air. Not only that, but iron probably rains down through the clouds.

June 7, 2023June 7, 2023 by Evan Gough

Is it Time for a New Definition of “Habitable?”

This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between the planet and Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface. Credit: ESO/M. Kornmesser

Things tend to move from the simple to the complex when you’re trying to understand something new. This is the situation exoplanet scientists find themselves in when it comes to the term ‘habitable.’ When they were discovering the first tranche of exoplanets, the term was useful. It basically meant that the planet could have liquid water on its surface.

But now that we know of over 5,000 confirmed exoplanets, the current definition of habitable is showing its age.

June 1, 2023June 1, 2023 by Evan Gough

JWST Scans an Ultra-Hot Jupiter’s Atmosphere

This artist's illustration shows WASP 18 b, a hot Super-Jupiter that orbits its star in less than one day. Image Credit: NASA, ESA, and G. Bacon (STScI).

When astronomers discovered WASP-18b in 2009, they uncovered one of the most unusual planets ever found. It’s ten times as massive as Jupiter is, it’s tidally locked to its Sun-like star, and it completes an orbit in less than one Earth day, about 23 hours.

Now astronomers have pointed the JWST and its powerful NIRSS instrument at the ultra-Hot Jupiter and mapped its extraordinary atmosphere.

May 31, 2023May 31, 2023 by Evan Gough

The Kepler Mission’s Final Three Planets?

With the help of citizen scientists, astronomers discovered what may be the last three planets that the Kepler Space Telescope saw before it was retired. This illustration depicts NASA’s Kepler Space Telescope, which retired in October 2018, and three planets discovered in its final days of data. Image Credit: NASA’s Jet Propulsion Laboratory

NASA’s Kepler spacecraft ended its observations in October 2018 after nine and a half years, a solid six years beyond its planned duration. It discovered 2,711 confirmed exoplanets and another 2,056 exoplanet candidates as of August 2022.

Now, astronomers at MIT and the University of Wisconsin uncovered three more exoplanets in the data from Kepler’s final days of observations. They needed the help of dedicated amateurs to do it.

May 31, 2023May 31, 2023 by Laurence Tognetti

A Third of Planets Orbiting Red Dwarf Stars Could be in the Habitable Zone

A recent study published in the Proceedings of the National Academy of Sciences, a pair of researchers from the University of Florida (UF) examine orbital eccentricities for exoplanets orbiting red dwarf (M dwarf) stars and determined that one-third of them—which encompass hundreds of millions throughout the Milky Way—could exist within their star’s habitable zone (HZ), which is that approximate distance from their star where liquid water can exist on the surface. The researchers determined the remaining two-thirds of exoplanets orbiting red dwarfs are too hot for liquid water to exist on their surfaces due to tidal extremes, resulting in a sterilization of the planetary surface.

May 30, 2023May 30, 2023 by Evan Gough

A New Place to Search for Habitable Planets: “The Soot Line.”

Artist impression of a young planet-forming disk illustrating the respective locations of the soot and water-ice lines. Planets born interior to the soot line will be silicate-rich. Planets born interior to the water-ice line, but exterior to the soot line will be silicate and soot-rich (“Sooty Worlds”). Planets born exterior to the water-ice line will be water worlds. Image credit: Ari Gea/SayoStudio.

The habitable zone is the region around a star where planets can maintain liquid water on their surface. It’s axiomatic that planets with liquid water are the best places to look for life, and astronomers focus their search on that zone. As far as we can tell, no water equals no life.

But new research suggests another delineation in solar systems that could influence habitability: The Soot Line.

May 15, 2023May 15, 2023 by Brian Koberlein

Two Super-Earths Found Orbiting a Red Dwarf Star at the Edge of the Habitable Zone

Illustration of NASA's Transiting Exoplanet Survey Satellite. Credit: NASA's Goddard Space Flight Center

NASA’s Transiting Exoplanet Survey Satellite, or TESS, was designed to find other worlds. Following in the tradition of the Kepler spacecraft, TESS has a hundred thousand stars looking for small but regular dips in their brightness. These dips are typically caused by planets as they pass in front of the star. TESS has been quite effective, logging nearly 6,000 candidate exoplanets. Confirming or rejecting these candidates takes time, but it has led to some interesting discoveries.

May 12, 2023May 12, 2023 by Evan Gough

JWST Looks at the Atmosphere of a Stormy, Steamy Mini-Neptune

This artist’s concept depicts the planet GJ 1214 b, a “mini-Neptune” with what is likely a steamy, hazy atmosphere. A new study based on observations by NASA’s Webb telescope provides insight into this type of planet, the most common in the galaxy. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

Just because there’s no Mini-Neptune in our Solar System doesn’t mean they’re not common. They appear to be widespread throughout the Milky Way, and according to NASA, are the most common exoplanet type. GJ 1214 b is one of them.

May 3, 2023May 3, 2023 by Brian Koberlein

Even if There's Life on TRAPPIST-1, We Probably Can't Detect it

A size comparison of the planets of the TRAPPIST-1 system. Credit: NASA/R. Hurt/T. Pyle

If we ever find life on other worlds, it is unlikely to be a powerful message from space. It’s certainly possible that an alien civilization specifically sends us a radio message like a scene out of Contact, but the more likely scenario is that we observe some kind of biological signature in an exoplanet’s atmosphere, such as oxygen or chlorophyll. But as a recent study shows, that could be more difficult than we thought.

April 30, 2023April 30, 2023 by Brian Koberlein

Bizarre Exoplanet Breaks All the Orbital Rules

Artist's view of WASP-39b, a hot gas planet similar to WASP-131b. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

In our solar system, the planetary orbits all have a similar orientation. Their orbital planes vary by a few degrees, but roughly the planets all orbit in the same direction. This invariable plane as it’s known also has an orientation within a few degrees of the Sun’s rotational plane. Most planetary systems have a similar arrangement, where planetary orbits and stellar rotation are roughly aligned, but a few exoplanets defy this trend, and we aren’t entirely sure why.