Chris Smith (KRBwyle)/NASA's Goddard Space Flight Center
An artists's conception shows planet LP 791-18d. The volcanically active planet, which is a similar size to Earth, was discovered by NASA's Spitzer Space Telescope.
NASA, ESA, CSA, Joseph Olmsted (STScI)
This artist's illustration depicts the rocky exoplanet GJ 486 b, which orbits a red dwarf star located 26 light-years away from Earth. Astronomers have detected hints of water vapor in the system, but they can't be sure if it signifies a planetary atmosphere or if it's part of the star.
NASA/JPL-Caltech/Robert Hurt
This illustration shows an Earth-size exoplanet called TOI 700 e, discovered orbiting the small, cool M dwarf star TOI 700, which is located 100 light-years away. Its other Earth-size sibling, TOI 700 d, can be seen in the distance.
NASA's Goddard Space Flight Center
TOI 700 d is the first potentially habitable Earth-size planet spotted by NASA's planet-hunting TESS mission.
Patricia Klein/MPIA
Artist's impression of the exoplanet WASP-121 b. It belongs to the class of hot Jupiters. Due to its proximity to the central star, the planet's rotation is tidally locked to its orbit around it. As a result, one of WASP-121 b's hemispheres always faces the star, heating it to temperatures of up to 3000 degrees Celsius. The night side is always oriented towards cold space, which is why it is 1500 degrees Celsius cooler there.
ESO/L. Calçada
This artist's impression shows a close-up view of Proxima d, a planet candidate recently found orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The planet is believed to be rocky and to have a mass about a quarter that of Earth. Two other planets known to orbit Proxima Centauri are visible in the image too: Proxima b, a planet with about the same mass as Earth that orbits the star every 11 days and is within the habitable zone, and candidate Proxima c, which is on a longer five-year orbit around the star.
Helena Valenzuela Widerström
The discovery of a second exomoon candidate hints at the possibility that exomoons may be as common as exoplanets.
European Space Agency
This artist's impression shows the football-shaped planet WASP-103b (left) closely orbiting its host star.
Janson et al./ESO
This image shows double-star system b Centauri and its giant planet b Centauri b. The star pair is the bright object at top left. The planet is visible as a bright dot in the lower right. The other bright dot (top right) is a background star.
Adam Makarenko/W. M. Keck Observatory
This artist's rendering shows a Jupiter-like planet orbiting a dead white dwarf star 6,500 light-years away from Earth. The planet survived the violent phases of stellar evolution leading to the star's death.
M. Kornmesser/ESO
This artist's illustration shows the night-side view of the exoplanet WASP-76b, where iron rains down from the sky.
Amanda Smith/University of Cambridge
Astronomers have identified a new class of habitable planets, which they call Hycean planets. These are hot, ocean-covered planets with hydrogen-rich atmospheres.
M. Kornmesser/ESO
This artist's illustration shows L 98-59b, one of the planets in a planetary system 35 light-years away from Earth. This planet has half the mass of Venus.
Scott Wiessinger/NASA
In this artist's illustration, two gaseous exoplanets can be seen orbiting the bright sun-like star HD 152843.
JPL-Caltech/NASA
An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth.
From NRAO/S. Dagnello
This artist's conception depicts a violent flare erupting on the star Proxima Centauri as seen from the viewpoint of a planet orbiting the star called Proxima Centauri b.
NASA/ESA/R. Hurt
After losing its gaseous envelope, the Earth-size core of an exoplanet formed a second atmosphere. It's a toxic blend of hydrogen, methane, and hydrogen cyanide that is likely fueled by volcanic activity occurring beneath a thin crust, leading to its cracked appearance.
NASA/JPL-Caltech
This illustration shows the metaphorical measuring of the density of each of the seven planets in the nearby TRAPPIST-1 system. New measurements have revealed the most precise densities yet for these planets and they're very similar -- which means they also likely have similar compositions.
L. Calçada/ESO
This artist's illustration shows the view from the furthest planet in the TOI-178 system.
W. M. Keck Observatory/Adam Makarenko
This artist's illustration shows TOI-561b, one of the oldest and most metal-poor planetary systems discovered yet in the Milky Way galaxy. Astronomers found a super-Earth and two other planets orbiting the star.
ESA/Hubble/M. Kornmesser
This massive and distant exoplanet, called HD106906 b, has an elongated and angled orbit that causes it to take 15,000 Earth years to complete one lap around its twin stars.
Jan Skowron/Astronomical Observatory, University of Warsaw
This is an artist's impression of a free-floating rogue planet being detected in our Milky Way galaxy using a technique called microlensing. Microlensing occurs when an object in space can warp space-time.
ESA
This is an artist's impression of exoplanet WASP-189 b orbiting its host star. The star appears to glow blue because it's more than 2,000 degrees hotter than our sun. The planet, which is slightly larger than Jupiter, has a tilted orbit around the star's poles rather than its equator.
NASA's Goddard Space Flight Ce
For the first time, an exoplanet has been found orbiting a dead star known as a white dwarf. In this artist's illustration, the Jupiter-sized planet WD 1856 b orbits the white dwarf every day and a half.
Shim/ASU/Vecteezy
This illustration shows a carbon-rich planet with diamond and silica as ts main minerals. Water can convert a carbon-rich planet into one that's made of diamonds. In the interior, the main minerals would be diamond and silica (a layer with crystals in the illustration). The core (dark blue) might be made of an iron-carbon alloy.
European Southern Observatory/Bohn et al.
This image shows a young sun-like star being orbited by two gas giant exoplanets. It was taken by the SPHERE instrument on European Southern Observatory's Very Large Telescope. The star can be seen in the top left corner, and the planets are the two bright dots.
Mark Garlick/University of Warwick
This artist's impression shows a Neptune-sized planet in the Neptunian Desert. It is extremely rare to find an object of this size and density so close to its star.
Mark Garlick
This is an artist's impression of the multiplanetary system of newly discovered super-Earths orbiting a nearby red dwarf star called Gliese 887.
NASA's Goddard Space Flight Center/Chris Smith (USRA)
The newly discovered exoplanet AU Mic b is about the size of Neptune.
European Southern Observatory/M. Kornmesser
This artist's impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. Proxima b is a little more massive than the Earth.
Jack Madden/Carl Sagan Institute/Cornell University
This is an artist's illustration of an exoplanet's atmosphere with a white dwarf star visible on the horizon. The starlight of a white dwarf filtered through the atmosphere of an exoplanet that's orbiting it could reveal if the planet has biosignatures.
Adam Makarenko/W. M. Keck Observatory
This is an artist's illustration of the Kepler-88 planetary system, where one giant exoplanet and two smaller planets orbit the Kepler-88 star. The system is more than 1,200 light-years away.

A version of this story appeared in CNN’s Wonder Theory science newsletter. To get it in your inbox, sign up for free here.

CNN  — 

There are more than 5,000 known worlds beyond our solar system.

Since the 1990s, astronomers have used ground and space-based telescopes to search for signs of planets beyond our tiny corner of the universe.

Exoplanets are notoriously difficult to directly image because they’re so far away from Earth.

But scientists know the signs, looking for wobbles of stars as orbiting planets use their gravitational pull, or dips in starlight as planets pass in front of their stellar hosts.

It’s highly likely that there are hundreds of billions more exoplanets just waiting to be discovered.

Part of the excitement around the James Webb Space Telescope is its ability to peer inside the atmospheres of potentially habitable planets and discover new worlds. This week, the space observatory certainly delivered.

Other worlds

NASA/ESA/CSA
This illustration depicts the exoplanet LHS 475 b, recently confirmed by the Webb telescope.

The Webb telescope confirmed the existence of an exoplanet for the first time since the space observatory launched in December 2021.

The world, known as LHS 475 b, is almost exactly the same size as Earth and located 41 light-years away in the Octans constellation.

Scientists can’t yet determine if the planet has an atmosphere, but the telescope’s sensitive capabilities picked up on a range of molecules. Webb will get another crack this summer at observing the planet to build upon this data.

The exoplanet was just one of Webb’s cosmic discoveries announced this week at the American Astronomical Society meeting in Seattle. What’s more, NASA’s Transiting Exoplanet Survey Satellite, or TESS, mission spied a second Earth-size exoplanet in an intriguing planetary system 100 light-years away — and the world just might be potentially habitable.

Force of nature

A year after the powerful eruption of the Hunga Tonga-Hunga Ha’apai volcano, scientists are still learning more surprising aftereffects of the event.

The explosion set off more than 25,500 lightning strikes in just five minutes, according to a new report. The event also triggered nearly 400,000 lightning strikes over six hours and accounted for half of all the lightning in the world during the eruption’s peak.

But even more surprising is that the January 2022 eruption was merely one factor in a year of extremes for lightning across the globe.

A long time ago

Carola Radke/MfN
Tree resin trapped this flower nearly 40 million years ago.

Blooming flowers are notoriously ephemeral, but a nearly 40 million-year-old specimen remains trapped in amber and frozen in time.

Researchers have taken another look at the extraordinary amber fossil, which was first documented in 1872. It’s the largest known flower to be fossilized in amber at 1.1 inches (28 millimeters) across.

Scientists were able to extract some of the flower’s pollen and discovered it’s related to a group of modern plants.

Meanwhile, archaeologists uncovered eight prehistoric ostrich eggs near an ancient fire pit in Israel.

Defying gravity

Russian space agency Roscosmos will launch an uncrewed replacement spacecraft to the International Space Station as a return vehicle for three crew members after their Soyuz capsule sustained damage in December.

Cosmonauts Sergey Prokopyev and Dmitri Petelin and NASA astronaut Frank Rubio launched to the space station in September.

A commission determined that damage to the Soyuz radiator’s pipeline was caused by a micrometeoroid impact, which created a hole with a diameter less than 1 millimeter, according to Roscosmos.

Crew members remain in good health, but their return to Earth — which has not been determined — will be delayed by at least several months.

Meanwhile, Virgin Orbit’s LauncherOne rocket attempted to launch from the United Kingdom, and California-based start-up ABL Space Systems set out to launch its RS1 rocket from Alaska. Both rockets failed, and investigations are underway to determine what went wrong.

Consequences

ALEXANDER KLEIN/AFP/AFP via Getty Images
A Qatar Airways Airbus A340 airplane leaves contrails in the sky.

The contrails that stream out behind aircraft crisscrossing our skies every day may seem harmless, but these wispy ice clouds are actually bad for the environment.

The condensation trails, which form when ice crystals cluster around small particles emitted by jet engines, trap more heat than carbon dioxide emissions that result from burning fuel. The longevity of the contrails depends on atmospheric conditions.

Researchers believe that slightly shifting the paths of specific flights could help reduce the damage.

Take note

Catch up on these stories before you go:

— An unusually brightening star might have been dust-bombed by a mysterious stellar companion for years.

— Europe’s “bog bodies,” the incredibly well-preserved mummies and skeletons discovered mired in peat and wetlands, reveal some of the brutal realities of prehistoric life.

— Astronomers have spotted the closest pair of supermassive black holes ever observed across multiple wavelengths of light. The cosmic bodies were brought together by colliding galaxies.

Like what you’ve read? Oh, but there’s more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writers Ashley Strickland and Katie Hunt. They find wonder in planets beyond our solar system and discoveries from the ancient world.