rocky exoplanet Archives

Schematic diagram of the idealised planetary system considered in this work with equally spaced planets (brown circles, semi-major axis ai) scattering comets (small dark blue circles) from the snow-line. The blue region represents the volatile-rich region of the disc where comets occur, and the green region represents the habitable zone. Low velocity cometary impacts onto habitable planets will follow the lower arrows, which sketch the dynamically cold scattering between adjacent planets. The dynamically hot scattering as shown by the upper arrows, will result in high velocity impacts. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Comets and Asteroids, Exoplanets, -moons, -comets, Meteorites & Asteroids, Panspermia, Status Report

Can Comets Deliver Prebiotic Molecules To Rocky Exoplanets?

by Keith CowingOctober 23, 2023October 20, 2023

In this work we consider the potential of cometary impacts to deliver complex organic molecules and the prebiotic building blocks required for life to rocky exoplanets. Numerical experiments have demonstrated […]

a. Model surface spectral flux, 𝐼𝑠 (𝜆;𝑇𝑠) , for planets within the middle of the habitable zone around parent stars of different effective temperatures, 𝑇𝑠. The spectral fluxes are taken from PHOENIX radiative transfer models (Husser et al. 2013) of surface spectral flux and the habitable distances are estimated according to a simple radiative equilibrium model outlined in the Methodology. A sparse range of temperatures is shown purely for clarity and the vertical dashed lines approximately demarcate the absorption regions for oxygenic and anoxygenic photosynthesis, with the former often referred to as photosynthetically active radiation (PAR). b. A schematic diagram of the concept of a dual-input noise-cancelling antenna. Two sub-populations of pigments with similar (but different) absorption maxima funnel energy to the reaction centre (RC) which oxidizes an electron donor and reduces an acceptor. The two absorbing populations tend to operate in series (e.g. Chl b transferring energy to Chl a in plant antenna complexes) and are subject to both external and internal noise. The former reflects the highly dynamic nature of the light-environment while the latter results from fluctuations of the energy transfer pathways within the antenna. c. An example of the matrix representation of Δ 𝑜𝑝 (𝜆0, Δ𝜆) for a fixed value of absorber width, 𝜎 = 10 nm. Above this is an illustration of two examples of antenna configuration superimposed on the 2800 K spectrum (dark red). 𝑇 = 2800 K is chosen here purely for illustrative purposes as it exhibits many sharp bands of optimal (and extremely sub-optimal) antenna configurations. Note the distinction between the standard deviation or ’width’, 𝜎, and the Full Width at Half Maximum, Γ 2.63𝜎 of the Gaussian peak. -- astro-ph.SR

Biochemistry & Organic Chemistry, Biophysics, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Plant Biology, Status Report

Photosynthesis Under A Red Sun: Predicting The Absorption Characteristics Of An Extraterrestrial Light-harvesting Antenna

by Keith CowingOctober 10, 2023October 9, 2023

Here we discuss the feasibility of photosynthesis on Earth-like rocky planets in close orbit around ultra-cool red dwarf stars. Stars of this type have very limited emission in the photosynthetically […]

Broadband light curves of the flare-affected transits of TRAPPIST-1b and f. The transit models are shown in orange, and the exponential fit to the integrations in both the transit and flare is shown in blue. The exponential fit is necessary to determine the shape of the transit light curve. As shown in the O-C diagrams at the bottom, we use an initial guess of c1 and c2 to fit the exponential, then subtract the exponential to obtain final values of c1 and c2. We note c1 and c2 represent the coefficients of the quadratic limb darkening equation. The first and third O-C diagrams are directly comparable and show the light curve with the final transit model removed. The middle O-C diagram shows an intermediate step in the determination of the TRAPPIST-1f transit model fit in which the initial guess on the transit model is subtracted prior to fitting and subtracting the exponential. The residuals of the middle panel therefore show the quality of the exponential fit. -- astro-ph.SR

Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Characterizing The Near-infrared Spectra Of Flares From TRAPPIST-1 During JWST Transit Spectroscopy Observations

by Keith CowingOctober 9, 2023October 9, 2023

We present the first analysis of JWST near-infrared spectroscopy of stellar flares from TRAPPIST-1 during transits of rocky exoplanets. Four flares were observed from 0.6–2.8 μm with NIRISS and 0.6–3.5 […]

Compositional evolution of lava planets interiors from an initial homogeneous molten state. Chemical fractionation occurs during planetary solidification because rock-forming elements do not have the same affinities for liquid and solid phases. For instance, FeO prefers to remain in the liquid rather than being incorporated in the solids. (a and b) Initial conditions. The magma ocean is well mixed and nearly entirely molten. The composition of the magma ocean corresponds to the bulk planet’s composition, i.e., 6% of FeO (BSE composition). This is the global magma ocean stage. (c and d) Onset of the mushy stage. The MO crystal fraction is about 50%. Iron-rich solids accumulate in the deep mantle. The most liquid part of the planet shows a FeO content of 10%. (e-f) End of the mushy stage. The FeO concentration of the MO reaches its maximum, 12%. (g-h) Solid-state stage. The iron-rich shallow magma ocean has been buried in the deep mantle. The day-side shallow magma ocean has a concentration of about about 2%. The solid mantle is strongly layered. Iron-rich solids remelts to form a basal magma ocean. -- astro-ph.EP]

Astrogeology, Biogeochemical Cycles & Geobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Exoplanets, -moons, -comets, Io, Status Report

Lava Planets Interior Dynamics Govern The Long-term Evolution Of Their Magma Oceans

by Keith CowingAugust 31, 2023August 30, 2023

Lava planets are rocky exoplanets that orbit so close to their host star that their day-side is hot enough to melt silicate rock. Their short orbital periods ensure that lava […]

Vertical flux of ozone (FO3 in molecules m−2 s −1 ) between 𝑃𝑚𝑎𝑥=190 hPa and 𝑃𝑚𝑖𝑛=8.2 hPa. The predominantly downward exchange at the locations of the Rossby gyres illustrates how the enhanced ozone columns are driven by the downward motions that are part of the stratospheric dayside-to-nightside circulation. -- astro-ph.EP

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

Stratospheric Dayside-to-nightside Circulation Drives The 3-D Ozone Distribution On Synchronously Rotating Rocky Exoplanets

by Keith CowingJune 5, 2023June 5, 2023

Determining the habitability and interpreting future atmospheric observations of exoplanets requires understanding the atmospheric dynamics and chemistry from a 3-D perspective.

Simulated emission spectra of TRAPPIST-1 c with MIRI photometric filter mean fluxes for water and CO2 atmospheres, obtained with the high-resolution, k-correlated MSEIRADTRAN model. Color boxes indicate the wavelength ranges of the different filters. — astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Interior-atmosphere Modelling To Assess The Observability Of Rocky Planets With JWST

by Keith CowingMay 3, 2023May 3, 2023

Super-Earths present compositions dominated by refractory materials. However, there is a degeneracy in their interior structure between a planet with no atmosphere and a small Fe content, and a planet […]

Exoplanets, -moons, -comets, Habitable Zones, Impact events, Press Release

Reduced Late Bombardment On Rocky Exoplanets Around M-dwarfs

by Keith CowingSeptember 28, 2022September 28, 2022

Ocean-vaporizing impacts of chemically reduced planetesimals onto the early Earth have been suggested to catalyse atmospheric production of reduced nitrogen compounds and trigger prebiotic synthesis despite an oxidized lithosphere.

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Variability in the Super-Earth 55 Cnc e

by Keith CowingMay 4, 2015November 30, 2023

Considerable progress has been made in recent years in observations of atmospheric signatures of giant exoplanets, but processes in rocky exoplanets remain largely unknown due to major challenges in observing […]

rocky exoplanet

Can Comets Deliver Prebiotic Molecules To Rocky Exoplanets?

Photosynthesis Under A Red Sun: Predicting The Absorption Characteristics Of An Extraterrestrial Light-harvesting Antenna

Characterizing The Near-infrared Spectra Of Flares From TRAPPIST-1 During JWST Transit Spectroscopy Observations

Lava Planets Interior Dynamics Govern The Long-term Evolution Of Their Magma Oceans

Stratospheric Dayside-to-nightside Circulation Drives The 3-D Ozone Distribution On Synchronously Rotating Rocky Exoplanets

Interior-atmosphere Modelling To Assess The Observability Of Rocky Planets With JWST

Reduced Late Bombardment On Rocky Exoplanets Around M-dwarfs

Variability in the Super-Earth 55 Cnc e

NASA Spaceline Current Awareness List #1,206 2 July 2026 (Space Life Science Research Results)

Older Than The Sun: Astronomers Find New Clues To The Origin Of Interstellar Comet 3I/ATLAS

Carl Sagan Month: Call For Participation

The Habitable Worlds Observatory Technology Development Plan

Searching For The Elusive CH2+ With The James Webb Space Telescope. Another Carbocation To Constrain Astrochemical Networks