It's been a landmark year for discovering new, fascinating worlds.
In 2022, NASA surpassed 5,000 confirmed exoplanets, which are alien worlds beyond our solar system. These include a diversity of distant planets, including (perhaps rocky) super-Earths, gas giants like Jupiter, "ice giants" like Neptune, and beyond. Although planetary scientists have discovered thousands of these curious places, it's likely there are over a trillion exoplanets in our Milky Way galaxy alone.
What's more, the James Webb Space Telescope — the most powerful such telescope ever built — peered into the atmospheres of some of these planets this year, giving scientists unprecedented insights into these still largely mysterious orbs.
Below you can read about the recent exoplanet discoveries made in 2022. (Stay tuned: Next year promises bounties of more fascinating detections in deep space.)
Planet hosts metal clouds and raining gems
Planetary scientists spot many far-off exoplanets by pointing specialized telescopes, like NASA's legendary Kepler telescope, at distant stars and looking for dips in their brightness. It's a strong hint that a planet passed in front of that star.
Sometimes, scientists can even glimpse an exoplanet's atmosphere (a feat that will grow more common with the powerful Webb telescope). Recently, researchers found that airborne metals and gems likely exist on the cooler side of WASP-121 b, an exoplanet some 855 light-years from Earth. There, it's cool enough for metals in the high atmosphere — like magnesium, iron, vanadium, chromium, and nickel — to condense into clouds.
What might such metallic clouds look like? "I don't think we can say what they'd look like for sure, because cloud formation is complicated and we don't have clouds like these to observe up close in our own solar system," Thomas Mikal-Evans, an astronomer at the Max Planck Institute for Astronomy and a lead author of the research, told Mashable.
But he speculated these extraterrestrial clouds could resemble dust storms on Earth. Some clouds might be colored blue or red. Others grey or green.
And, sometimes, the clouds could further condense into droplets, ultimately meaning gems raining from the sky.
A weird "rugby ball-shaped" planet
Most planets are spherical. But not WASP-103b.
The European Space Agency's (ESA) Cheops space telescope (short for CHaracterising ExOPlanet Satellite), found that WASP-103-b — a planet twice the size of Jupiter — zooms around its star in just a day. This causes extreme tugging on the planet, a much more intense version of how the moon tugs tides on Earth. Ultimately, this tugging has deformed the planet from its once spherical shape.
The Cheops satellite measures tiny changes in light, and was able to observe the planet's odd shape as it passed in front of its star. "The size of the effect of tidal deformation on an exoplanet transit light curve is very small, but thanks to the very high precision of Cheops we are able to see this for the first time," the ESA's Cheops project scientist, Kate Isaak, said in a statement.
A rare discovery on a "Super Neptune."
Some 150 light-years from Earth, astronomers detected a "super Neptune" (meaning a planet a little larger than Neptune) with water vapor in its atmosphere. That's a rarity.
"At 150 light-years, [TOI-674 b is] considered 'nearby' in astronomical terms," writes NASA, which is one reason scientists can glean the chemical make-up of its atmosphere.
"Many questions remain, such as how much water vapor its atmosphere holds," the space agency added. "But TOI-674 b’s atmosphere is far easier to observe than those of many exoplanets, making it a prime target for deeper investigation."
Perhaps the James Webb telescope, which will return its first cosmic images in July 2022, will peer deeper into this exoplanet's atmosphere.
A still-forming exoplanet
Planetary scientists discovered a giant, still-forming exoplanet called AB Aurigae b.
The over 30-year-old Hubble Space Telescope imaged the planet, which is developing in a still young and volatile disk of gas and dust, called a protoplanetary disk. The nascent solar system's star is just 2 million years old. (The sun, for context, is over 4.5 billion years old.).
The new planet is giant. Scientists suspect its nine times bigger than Jupiter. And it orbits profoundly far from its star, at some 8.6 billion miles away. That's over twice as far as Pluto is from the sun.
Unlike most planets, which researchers think formed when smaller objects in the planetary disk collided and grew into large, hot planetary objects, AB Aurigae b may have formed when its cooled disk broke up into big fragments.
A colossal ocean may completely cover this planet
One hundred light-years away in the cosmos, a sprawling ocean may slosh over the entirety of a distant planet.
In August, astronomers announced that the exoplanet TOI-1452 b is close in size to Earth and lies in a region of its solar system where liquid water could exist. Vast amounts of water — many times the amount of water on Earth — could account for the planet's lower density (as opposed to a world teeming with rock and metal). The team of over 50 scientists published their results in The Astronomical Journal.
"TOI-1452 b is one of the best candidates for an ocean planet that we have found to date," Charles Cadieux, an astronomer at the Université de Montréal who led the research, said in a statement.
It's possible an ocean makes up some 30 percent of TOI-1452 b's mass. On Earth, water makes up just one percent of the planetary mass.
A weird marshmallow-like planet
Meet the "fluffy" world TOI-3757 b. Astronomers think it has an atmospheric density similar to a marshmallow.
Atop a mountain in Arizona, astronomers at the Kitt Peak National Observatory used a 11.5-foot-wide telescope called WIYN to investigate the gassy Jupiter-like world some 580 light-years away in deep space. It orbits a common though curious type of star called a "red dwarf." These stars are much smaller and dimmer than the sun, but they're awfully fickle: They shoot out violent flares that can make nearby planets inhospitable.
Planetary scientists suggested two ideas for the planet's marshmallow-like atmosphere:
Gas giants like Jupiter start their lives as rocky cores many times Earth's mass. They use this mass to pull in nearby gas as the solar system forms, explains the National Science Foundation's NOIRLab, which runs big telescopes across the U.S. But the red dwarf star contains fewer heavy elements than other such stars, meaning the planet's rocky core may have formed slowly and "delayed" the process of pulling in that surrounding gas. Ultimately, TOI-3757 b was left with a less dense, fluffier atmosphere than other Jupiter-like planets orbiting these stars.
TOI-3757 b's orbit around its red dwarf star could be elliptical. "There are times it gets closer to its star than at other times, resulting in substantial excess heating that can cause the planet’s atmosphere to bloat," NOIRLab explains.
Unprecedented detection on a planet 700 light-years away
The powerful Webb telescope doesn't need to take pretty pictures to revolutionize our grasp of the cosmos.
Astronomers pointed the space observatory at WASP-39 b, a hot, gas giant closely orbiting a star 700 light-years away. And for the first time, they discovered "a full menu" of atoms and molecules in an exoplanet's clouds, and some are interacting. This latest detection (using specialized instruments called spectrometers) proves that astronomers can peer into the atmospheres of strange exoplanets and decipher what's transpiring or being made chemically — and if these worlds might then contain conditions that could potentially harbor life.
A star's light can often stoke chemical reactions on a planet, a process dubbed "photochemistry." This is what's happening on WASP-39 b.
"Planets are sculpted and transformed by orbiting within the radiation bath of the host star," Natalie Batalha, an astronomer at the University of California, Santa Cruz, who contributed to the new research, said in a statement. "On Earth, those transformations allow life to thrive."
Riveting evidence of 'water worlds' in deep space
Scientists spotted two "water worlds," in the same solar system, that they think could be teeming with water. Water could compose up to half of these planets' mass.
(That's huge. For reference, Earth, which is blanketed in rich, biodiverse oceans, is still considered a relatively dry place, as just one percent of our planet's mass is water.)
"It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time," Björn Benneke, an exoplanet researcher at the University of Montreal who worked on the research, said in a statement. The research was published this week in the science journal Nature.
The planets are called Kepler-138 c and Kepler-138 d, named after NASA's Kepler Space Telescope, which identified thousands of exoplanets and revolutionized our grasp of what lies beyond our solar system, in the deep cosmos. These two water worlds inhabit a solar system 218 light-years away and are "unlike any planets in our Solar System," noted the European Space Agency.
You can read the full story on Mashable.
Topics NASA
