Astronomers have achieved significant advancements this year in exploring and comprehending planets that exist outside our solar system. According to NASA, the tally of verified **exoplanets** — planets that revolve around stars other than our sun — has surged to **5,788**, with thousands more pending verification. All these celestial bodies inhabit our galaxy, although researchers believe they might have identified one outside the Milky Way back in 2021.
While this increasing number is impressive, it constitutes merely a minuscule portion of the planets believed to be dispersed throughout the universe. With **hundreds of billions of galaxies** and **trillions of stars**, the universe is probably teeming with innumerable worlds. If the majority of stars contain at least one planet, the vast figures are astonishing.
Every exoplanet possesses distinct traits, including its own chemistry and environmental conditions. Among the findings are **water worlds**, planets characterized by **multiple sunsets**, **volcanic terrains**, **rogue planets**, and even worlds with **clouds that differ significantly from those on Earth**.
### Investigating Exoplanets with the James Webb Space Telescope
The **James Webb Space Telescope (JWST)** is transforming our capacity to examine these far-off worlds. As the premier infrared observatory, it allocates roughly 25% of its time to the investigation of exoplanets. By scrutinizing the atmospheres of these planets, scientists can discover key attributes, including the potential for life.
Shortly, Webb will undertake an ambitious investigation of **rocky exoplanets** that orbit small, cool stars to explore whether they possess atmospheres. In the upcoming two years, researchers intend to focus on a dozen nearby planets, aiming to determine if these worlds might support air.
Here are some of the most captivating exoplanet discoveries from the previous year:
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### A Planet That Emits an Odor Like Rotten Eggs
Astronomers utilized the JWST to observe **L 98-59 d**, a planet located 35 light-years away in the constellation Volans. Its atmosphere contains **sulfur dioxide** and **hydrogen sulfide**, gases that probably give the planet a scent reminiscent of burnt matches and spoiled eggs. This world likely features a molten or volcanic surface, rendering it uninhabitable by our standards.
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### A Super-Earth with an Enigmatic Companion
The planet **TOI-715 b**, positioned 137 light-years away, is classified as a **super-Earth** — a planet slightly larger than Earth — that orbits its star within the **habitable zone**, where liquid water might be present. Even more compelling is the speculation of a smaller, Earth-sized companion planet in proximity, which scientists are keen to explore further.
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### A Validated Exoplanet Around Barnard’s Star
Following years of conjecture and false alarms, scientists have validated the presence of a planet orbiting **Barnard’s star**, one of the sun’s nearest stellar neighbors. The planet, **Barnard b**, completes an orbit every three days and exhibits a surface temperature of approximately 250°F. It is situated 20 times closer to its star than Mercury is to the sun.
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### A Mild Venus-Like Planet
Researchers identified **Gliese 12 b**, an Earth-sized planet referred to as an “exo-Venus.” In contrast to Venus, which has an extremely high surface temperature of about 900°F, Gliese 12 b is believed to be significantly cooler, with an average temperature around 107°F. This distinction makes it the closest temperate Earth-sized planet discovered to date.
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### The First “Steam World”
Scientists have uncovered direct evidence of a **”steam world”** — a planet enveloped in moist warmth. The planet, **GJ 9827 d**, is situated roughly 100 light-years away in the constellation Pisces. It is about twice the size of Earth and possesses an atmosphere that is almost entirely made up of water vapor, a scenario that was previously only hypothesized.
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### A Semi-Lava Exoplanet
The planet **HD 63433 d**, located 73 light-years away, is marginally larger than Earth but markedly different in many aspects. It is extremely young, at only 400 million years, and likely has one side covered in molten lava due to its closeness to its star. A year on this planet equals merely four Earth days.
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### An Eyeball-Like Exoplanet
The exoplanet **LHS 1140 b**, found 48 light-years away in the constellation Cetus, may resemble an icy globe akin to Jupiter’s moon Europa or could possess a liquid ocean directed towards its star, creating a “bullseye” appearance. If this is the case, the water at the middle of the ocean could have a pleasant temperature of 68°F.
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### A Luminous Volcanic World
In a stellar system 66 light-years away, scientists discovered **HD 104067**, a planet so volcanic that it glows with a red-hot hue, reminiscent of Jupiter’s moon Io. The extreme volcanic