Exoplanets Archives

October 27, 2023October 27, 2023 by Evan Gough

JWST Sees Four Exoplanets in a Single System

This artist’s rendering shows the star HR 8799 and one of its four planets, HR 8799c. It illustrates the system at an early stage of evolution. It also shows the star's dusty disk and rocky inner planets. Credit: Dunlap Institute for Astronomy & Astrophysics

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

October 27, 2023October 27, 2023 by Evan Gough

What’s the Best Way to Find Planets in the Habitable Zone?

This artist's illustration of Kepler 22-b, an Earth-like planet in the habitable zone of a Sun-like star about 640 light years (166 parsecs) away. Credit: NASA/Ames/JPL-Caltech

Despite the fact that we’ve discovered thousands of them, exoplanets are hard to find. And some types are harder to find than others. Naturally, some of the hardest ones to find are the ones we most want to find. What can we do?

Keep working on it, and that’s what a trio of Chinese scientists are doing.

October 26, 2023October 26, 2023 by Evan Gough

An Exo-Neptune Beat the Odds and Kept its Atmosphere

An artist impression of exoplanet LTT9779b orbiting its host star. Credit: Ricardo Ramírez Reyes (Universidad de Chile)

As planet-hunting scientists find more and more planets, they’ve encountered some puzzles. One of them concerns the lack of Neptune-size worlds orbiting close to their stars. Astronomers think that these planets aren’t massive enough to retain their atmospheres in the face of their stars’ powerful radiation, which strips it away.

But at least one of these planets has retained its atmosphere. How?

October 20, 2023October 20, 2023 by Evan Gough

Do Red Dwarfs or Sunlike Stars Have More Earth-Sized Worlds?

This artist's concept illustrates a red dwarf star surrounded by exoplanets. Credit: NASA/JPL-Caltech

Earth is our only example of a habitable planet, so it makes sense to search for Earth-size worlds when we’re hunting for potentially-habitable exoplanets. When astronomers found seven of them orbiting a red dwarf star in the TRAPPIST-1 system, people wondered if Earth-size planets are more common around red dwarfs than Sun-like stars.

But are they? Maybe not.

October 18, 2023October 18, 2023 by Laurence Tognetti

An Exoplanet so Hot it has Clouds Made of Quartz

Artist illustration showing what WASP-17 b could look like based on data obtained from a myriad of ground- and space-based telescopes, including NASA’s Hubble, Webb, and the retired Spitzer space telescopes. This most recent study used MIRI (Webb’s Mid-Infrared Instrument) to identify nanocrystals of quartz within the clouds WASP-17 b. (Credit: NASA, ESA, CSA, and R. Crawford (STScI))

A recent study published in The Astrophysical Journal Letters used data obtained by the James Webb Space Telescope’s (JWST) Mid-Infrared Instrument (MIRI) to identify the presence of quartz nanocrystals in the upper atmosphere of WASP-17 b, an exoplanet whose mass and radius are approximately 0.78 and 1.87 that of Jupiter, respectively, and is located approximately 1,324 light-years from Earth. WASP-17 b is classified as a “puffy” hot Jupiter due to its 3.7-day orbital period, meaning the extreme temperatures could cause unique chemical processes to occur within its atmosphere, but the astronomers were still surprised by the findings.

October 11, 2023October 11, 2023 by Andy Tomaswick

What Would It Take to See Exoplanet Volcanoes?

Even with the clearest image from the best telescope in the world, astronomers still won’t know what they’re looking at. It takes a fundamental understanding of physics, particularly how light works, to glean scientific data from the images that telescopes like the James Webb Space Telescope (JWST) capture. To help with that understanding, a whole group of physics modelers specialize in trying to understand what different scenarios would look like with different telescope technologies. A new paper fits neatly into this mold, where researchers from UC Riverside, NASA Goddard, American University, and the University of Maryland decided to model what they think volcanic activity would look like on an exoplanet around a Sun-like star.

October 4, 2023October 4, 2023 by Brian Koberlein

Old Stars Don't Have Hot Jupiters

Hot Jupiters may not last long near Sun-like stars. Credit: NASA/JPL-Caltech

As we began to discover hundreds, then thousands of exoplanets, we found that there were two types of worlds unlike anything in our solar system. The first are super-Earths. These worlds straddle the line between large rocky worlds like Earth and small gas planets like Neptune. The second are hot Jupiters. Large gas giants that orbit their star in a matter of days. While there may be a super-Earth lurking at the outer edge of our solar system, we know our Sun has no hot Jupiters. This is a little surprising since close-orbiting gas giants seem to be fairly common. But a new study could explain why our solar system has no planet Vulcan.

September 28, 2023September 28, 2023 by Evan Gough

Is it Life, or is it Volcanoes?

This artist's illustration shows an exoplanet with active volcanoes. But from a great distance we can't see the volcanoes, only the effect they have on their atmospheres, and that can muddy the waters when it comes to biosignatures. Image Credit: NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)

Astronomers are working hard to understand biosignatures and how they indicate life’s presence on an exoplanet. But each planet we encounter is a unique puzzle. When it comes to planetary atmospheres, carbon is a big piece of the puzzle because it has a powerful effect on climate and biogeochemistry. If scientists can figure out how and where a planet’s carbon comes from and how it behaves in the atmosphere, they’ve made progress in solving the puzzle.

But one of the problems with carbon in exoplanet atmospheres is that it can send mixed signals.

September 27, 2023September 27, 2023 by Evan Gough

How Do Lava Worlds Become Earth-Like, Living Planets?

This is an artist's illustration of Kepler-10 b, a suspected magma ocean planet about 560 light years away. Image Credit: NASA/Kepler Mission/Dana Berry

Earth was once entirely molten. Planetary scientists call this phase in a planet’s evolution a magma ocean, and Earth may have had more than one magma ocean phase. Earth cooled and, over 4.5 billion years, became the vibrant, life-supporting world it is today.

Can the same thing happen to exo-lava worlds? Can studying them shed light on Earth’s transition?

September 25, 2023September 25, 2023 by Evan Gough

Gaia is Now Finding Planets. Could it Find Another Earth?

Artist's impression of the ESA's Gaia Observatory. Credit: ESA

The ESA launched Gaia in 2013 with one overarching goal: to map more than one billion stars in the Milky Way. Its vast collection of data is frequently used in published research. Gaia is an ambitious mission, though it seldom makes headlines on its own.

But that could change.