rocky exoplanet Archives - Page 3 of 13 - Astrobiology

Topography-Induced Stationary Waves

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Radiation, Status Report

Topography-Induced Stationary Waves And The Onset Of Nightside Warming On Rocky Planets Around M-dwarf Stars

by Keith CowingFebruary 26, 2026February 26, 2026

Among potentially habitable worlds, rocky planets orbiting M dwarfs offer the most favorable prospects for atmospheric characterization, yet their climates may differ substantially from those of Earth analogs.

Mass–radius distribution of planets from Model I compared with the observed planets around G-type host stars from the TEPCat catalog Southworth (2011). Top: Weighted mass–radius distribution of simulated rocky planets and water worlds, shown with a color map of water mass fraction (WMF). Bottom: The same weighted distribution shown without the WMF color map, with weight contours highlighted to illustrate regions of higher model likelihood and observational completeness. The model broadly agrees with the observed distribution for planets smaller than ∼ 3 R⊕ in regions of high weights but fails to explain planets larger than ∼ 3 R⊕, suggesting the presence of a H/He-rich population, comprising ∼ 15% of the full TEPCat sample and ∼ 20% of the TEPCat sub-Neptunes. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Ice Giant, Status Report, Water/Hycean Worlds & Oceanography

The Radius Cliff is a Waterfall: Explaining Sub-Neptune Exoplanets With Steam Worlds

by Keith CowingFebruary 17, 2026February 17, 2026

The demographics of Kepler planets provide a key testbed for models of planet formation and evolution, particularly for explaining the radius valley separating super-Earths and sub-Neptunes.

Artist's impression of the planetary system around the star LHS 1903. Credit: ESA

Exoplanets, -moons, -comets, Gas Giants, Press Release, Stellar Cartography

Study Reveals A Planetary System With An Unexpected Rocky Planet In Its Outer Region

by Keith CowingFebruary 16, 2026February 16, 2026

An international scientific team, led by the University of Warwick and involving the Canary Islands Institute of Astrophysics, has used the European Space Agency’s Cheops satellite to discover that the […]

Planet mass (or minimum mass) as a function of orbital period for planetary systems hosting cold Jupiters.

Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Ice Giant, Icy Worlds, Status Report, Stellar Cartography

TESS Planets In Known Radial Velocity Cold Jupiter Systems: Hot Super Earth Occurrence Is Enhanced By Cold Jupiters

by Keith CowingFebruary 14, 2026February 14, 2026

The correlation between inner super-Earths (SEs) and outer cold Jupiters (CJs) provides an important constraint on the formation and dynamical evolution of planetary systems. Previous studies have suggested a positive […]

Cheops open questions: How do planets form?

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Press Release, Stellar Cartography

Cheops Discovers Late Bloomer Planet From Another Era

by Keith CowingFebruary 13, 2026February 13, 2026

Many Vile Earthlings Munch Jam Sandwiches Under Newspapers and My Very Educated Mother Just Served Us Nachos. What sounds like gibberish half-sentences are memory aids taught to children to help […]

Schematic of some of the key processes throughout planet formation that influence carbon supply and retention. (a) Key ice/grain sublimation fronts in the disk noted (CO2 between water–CO and that of Silicates at inner disk edge not shown). Planets forming in these locations will receive different compositions at birth (Öberg et al. 2011). Dust that grows beyond the “soot” line (Lodders 2004, Kress et al. 2010, Li et al. 2021) will be rich in refractory carbon content and at greater distances molecular ices. (blow-out:) The drift of carbon-rich pebbles from the outer disk is a key process in carbon supply. Drift itself is influenced by pressure bumps that can lead to a pile-up of pebbles that can be potential sites for planetesimal and planet formation (shown on left side of disk). (b) Solids accrete ice mantles, sublimate key components at sublimation fronts and can collide leading to both growth and fragmentation. (c) Rocky planets and cores of gas-rich planets grow and gain carbon through accretion of pebbles (top) and/or planetesimals (bottom). Impacts of larger planetesimals can also strip atmospheric gas and also supply material. (d) heavy element differentiation can take carbon to the core, and the resulting magma ocean/atmosphere equilibrium can influence atmospheric composition with lighter gases escaping depending on the planet mass. Figure credit to N. Fuller and Sayo Studio. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release

Carbon From Interstellar Clouds To Habitable Worlds

by Keith CowingFebruary 12, 2026February 12, 2026

Carbon is an essential element for a habitable world. Inner (r < 3 au) disk planetary carbon compositions are strongly influenced by supply and survival of carbonaceous solids. Here we […]

TESS 2-min cadence photometry of TOI-237 obtained with the TESS automatic aperture. Each of the panels shows the Sectors 2, 29, and 69, respectively. TOI-237 b is highlighted in blue, and TOI-237 c (TIC 305048087.02) in orange. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Hidden Gems In TESS: Sherlock Finds Two New Rocky Planets Around Nearby M Dwarfs

by Keith CowingFebruary 10, 2026February 10, 2026

The Hidden Gems project searches the TESS data for additional planets transiting low-mass stars in confirmed systems. Our goal is to identify planet candidates that are below the detection threshold […]

Stability analysis of the TOI-5788 planetary system. For fixed initial conditions (Table 4), the parameter space of the system is explored by varying the orbital period and the eccentricity of planet c (left panel) and the eccentricities of both planets (right panel). The step size is 0.0025 in the eccentricities, 0.001 d in the orbital period of planet b, and 0.003 d in the orbital period of planet c. For each initial condition, the system is integrated over 5000 yr and, from a frequency analysis of the mean longitude of the outer planet, a stability indicator is calculated. The colours in the plot represent the chaotic diffusion, measured by the variation in the frequency (see text). Red points correspond to highly unstable orbits, whilst blue points correspond to orbits which are likely to be stable on Gyr timescales. The black dots show the values of the best fit solution (Table 4). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography

Discovery and Characterisation of Two Exoplanets Orbiting the Metal-poor, Solar-type Star TOI-5788 with TESS, CHEOPS, and HARPS-N

by Keith CowingJanuary 28, 2026January 28, 2026

We present the discovery and characterisation of two transiting exoplanets orbiting the metal-poor, solar-type star TOI-5788.

Mass mixing ratios and condensate/cloud of the O2/CO2 atmosphere - model 5. The 15 major gas phase species are shown in the left hand side column and the solid and liquid species in the right hand side column.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Hot And cloudy: High Temperature Clouds In Super-Earths And Sub-Neptunes

by Keith CowingJanuary 26, 2026January 26, 2026

JWST observations provide for the first time evidence for an atmosphere on a rocky exoplanet – 55 Cnc e. The atmosphere of 55 Cnc e is hot with Teq>2000K and […]

Representative sections of (a) 1M⊕ and (b) 10M⊕ planets as a function of depth and pressure. Both were created using the Perple X software with the thermodynamic database of Stixrude & Lithgow-Bertelloni (2011) (see e.g., Sect. 5.7) assuming an Earth-like composition (Fe/Mg = 0.9, Si/Mg = 0.9, Ca/Mg = 0.07, Al/Mg = 0.09, and 8 wt % mantle FeO). Cpx = clinopyroxene, Opx = orthopyroxene, and C2/C = C2/C orthopyroxene. The garnet is majoritic garnet. Perovskite is silicate-perovskite. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Status Report

Toward Reliable Interpretations of Small Exoplanet Compositions: Comparisons and Considerations of Equations of State and Materials Used in Common Rocky Planet Models

by Keith CowingJanuary 23, 2026January 23, 2026

The bulk compositions of small planets (Rp<2R⊕) are directly linked to their formation histories, making reliable compositional constraints imperative for testing models of planet formation and evolution.