Two Rocky Earth-Sized Exoplanets Discovered Around Nearby Star By NASA’s TESS

NASA’s TESS has uncovered two rocky Earth-sized planets around a nearby star, including one super-Earth with an Earth-like interior and extraordinary density.

Astronomers using NASA’s Transiting Exoplanet Survey Satellite (TESS) have confirmed the discovery of two rocky exoplanets orbiting a nearby K-type star, designated TOI-2322. The results, published on August 25, 2025, in a detailed paper on arXiv, highlight how the ongoing TESS mission continues to expand the catalog of known worlds beyond our solar system, with particular interest in planets that share characteristics with Earth.

Launched in 2018, TESS was designed to scan nearly the entire sky, focusing on about 200,000 of the brightest nearby stars in search of periodic dips in brightness caused by planets crossing in front of their host stars. Since the start of its mission, TESS has generated over 7,600 candidate exoplanets, known as TESS Objects of Interest (TOIs). Of these, 686 have been confirmed as genuine exoplanets through follow-up observations using ground-based telescopes.

The discovery of TOI-2322 b and TOI-2322 c demonstrates the importance of combining TESS detections with precise measurements from high-resolution instruments like the ESPRESSO spectrograph, located at the Very Large Telescope in Chile. By analyzing stellar light and using radial velocity techniques, astronomers can determine both the masses and compositions of exoplanets, moving beyond simple detection toward deeper physical characterization.

TESS target pixel file for TOI-2322 for sector 27. The target star is labeled as 1 and marked by a white cross. Credit: arXiv (2025). DOI: 10.48550/arxiv.2508.18094

The planetary system lies about 195 light-years away, making it relatively close in galactic terms. Its host, TOI-2322 (TIC 300812741), is a K4-type star with properties that distinguish it from our Sun. The star is about 30% smaller and less massive, with an effective temperature of 4,664 K and a slightly lower metallicity of –0.12 dex. Astronomers estimate its age at roughly 3.9 billion years, placing it in a similar evolutionary stage as the Sun but with different stellar dynamics.

The star’s rotation period of 21.28 days closely overlaps with the orbital period of one of its planets, TOI-2322 c. This unusual alignment presents a challenge for separating signals caused by stellar activity from those generated by orbiting planets. For researchers, this makes TOI-2322 an ideal laboratory to test advanced data analysis techniques aimed at improving detection accuracy.

The first planet, TOI-2322 b, is the closest to the star. It is nearly the same size as Earth and is estimated to have a mass of less than 2.03 Earth masses. It orbits at a distance of just 0.09 AU (less than one-tenth the distance from Earth to the Sun), completing a revolution every 11.3 days. Its estimated equilibrium temperature of 603 K (329 °C) makes it too hot for liquid water on its surface, but its rocky nature still places it in a compelling category for understanding planetary formation and composition.

While not likely habitable, TOI-2322 b provides critical insights into the diversity of rocky exoplanets. Its small mass and compact orbit can help astronomers refine models of how terrestrial planets form around stars smaller and cooler than the Sun.

The second planet, TOI-2322 c, is larger and more massive. With a radius of 1.87 Earth radii and a mass about 18 times that of Earth, it boasts an unusually high density of 14.69 g/cm³, suggesting an interior composition strikingly similar to Earth’s. Its orbital path lies at 0.13 AU from the host star, with a 20.2-day orbit. The equilibrium temperature, at around 500 K (227 °C), is lower than that of TOI-2322 b but still far too high to support Earth-like surface conditions.

Despite the extreme environment, TOI-2322 c is particularly noteworthy because it represents one of the most massive planets yet discovered with an Earth-like internal structure. This makes it a rare benchmark for planetary composition studies, offering a natural laboratory for investigating how rocky super-Earths evolve in compact star systems.

The TOI-2322 system exemplifies the kind of planetary diversity that TESS was designed to uncover. Both planets are rocky, orbit their star at short distances, and yet differ dramatically in terms of mass and density. Their characteristics provide a unique opportunity to study how terrestrial planets scale in size and structure depending on their proximity to their host stars.

Furthermore, the system’s stellar rotation complicates radial velocity measurements, requiring astronomers to disentangle stellar activity from genuine planetary signals. This dual challenge of planetary detection and stellar noise makes TOI-2322 an invaluable case study for refining techniques that will be essential in the hunt for habitable exoplanets.

We have yet to discover a real “Goldilocks” world around a Sun-like star and temperatures that allow water to exist in liquid form.....................

Speed of light travel is too slow and impractical.

To fully explore the Universe we will need some form of space-bending like in DUNE or some form of ‘JUMPING’ like in Asimovian sci-fi.

Since we have never ‘officially’ met with any space aliens, it would seem that they have the same limitations as we do.

But we might have seen and encountered DRONE ships from alien civilizations, which would make more sense, since they could travel for thousands of years un-manned to explore the space nearest their home planets. Just like we do with the Moon, Mars and the rest of our system’s planets.................

18 times more massive than Earth is not “Earth like”

Compared to what? It has a solid surface and an atmosphere.

We have yet to discover a real “Goldilocks” world around a Sun-like star and temperatures that allow water to exist in liquid form...

Only a matter of time with our ever-improving sensing technology. That's why we need the spook-nerds to get crackin' and apply A.I. to the reverse engineering efforts on the debris. Otherwise we may as well turn that stuff in for recycling or hang it in the Air & Space Museum under "Speculative Alien Craft" (hide it in plain sight).

ALFadvice
"Never buy a spaceship at a
'Going Out Of Business' sale."

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