[biorxiv.org] Reconstruction of ancestral gene repertoires from extant genomes captures only the genes that survived; those lost from the record are invisible. Among the genes that did persist, selective pressures […]
Biogeochemical Cycles & Geobiology
Posted inMars
Hints of Clay On Mars
CRISM multispectral mapping data show strong clay (phyllosilicate) and pyroxene spectral signatures in different locations in and around this impact crater. Enhanced color can also help us to distinguish compositional […]
![Low-angle backscatter electron (LABE) imaging (Supplement 9) of sample OREX-220001-1 consisting of particles obtained from inside the SRC but exterior to the sample canister — including fragments of Bennu, SRC char, and metal. FG, fine-grained. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/OSIRIS-REx.png?resize=1200%2C800&ssl=1)
Posted inSample Return
OSIRIS-REx Returned a Pristine Sample of Asteroid Bennu: Takeaways from the Mission’s Contamination Control and Knowledge Program
[astro-ph.EP] NASA’s OSIRIS-REx mission had the objective of delivering a pristine sample from asteroid (101955) Bennu to Earth for scientific analysis–where “pristine” signifies the absence of foreign materials that could […]
Posted inSpace Weather & Heliophysics
Cosmic Radiation at Flight Altitudes Rises When the Sun Is Less Active
[Hebrew University of Jerusalem]. Radiation from space is constantly entering Earth’s atmosphere, but how much of it reaches the altitudes used by commercial aircraft depends not only on height and […]
Posted inBiosignatures & Paleobiology
The Long-term Persistence Of Microbial Biospheres Introduces A Temporal Bias 1 Into The Drake Equation: Implications For The Search For Extraterrestrial Life
[eartharxiv.org] The Drake equation was designed to estimate the number of communicative technological civilisations, not the prevalence of life. Its lifetime term therefore describes a detectable technological phase that may […]
Posted inBiosignatures & Paleobiology
A Dual-mineral Protection Mechanism For Organic Matter Preservation And Its Implications For Mars Habitability And Biosignature Detection
[Communications Earth & Environment] Understanding organic matter preservation in extreme environments is crucial for detecting potential biosignatures on Mars.
![Left: Average ocean fraction, calculated assuming a seawater freezing point of −1.8°𝐶 for Cases 1 and 3 and 0°𝐶 for Case 2. White shows the ice, and blue ocean. Middle: The mean near-surface air temperatures. Shown within the black contours are the regions where these vary between above and below freezing over the course of a single Earth year. Right: The mean surface temperatures. Also shown within the black contours are the regions where these vary between above and below freezing over the course of a single Earth year: these regions are narrower than the air ‘perifreezing zone’.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Sea-Ice.png?resize=1200%2C720&ssl=1)
Posted inWater/Hycean Worlds & Oceanography
Sea Ice As An Origin Of Life Location For Hycean And Ocean Worlds
[astro-ph.EP] Water worlds with potential deep oceans are at the forefront of currently observable exoplanetary habitability.
Posted inAstrogeology
Trans-Neptunian Objects Remember Their Past
[NASA]. For the first time, scientists used the joint power of NASA’s Hubble and James Webb Space Telescopes to study some of the most far-flung bodies in our solar system, […]
Posted inTitan
NASA Administrator Visits Dragonfly Mass Spectrometer (DraMS)
[NASA]. Dragonfly will explore sites of interest around Titan’s equatorial regions and collect samples of surface material for analysis inside DraMS, the Dragonfly Mass Spectrometer.
![Planets that will be observed with MIRI in transit, in JWST Cycles 1-5. As mentioned in section 5, we see a wide variety of planet sizes and equilibrium temperatures. The currently published planets are shown in black dots, and listed in Table 1 and Figure 1. We have ommitted the white dwarf planet WD 1856 b (Teq = 160K, Rp = 10.2R⊕, cycle 4), as well as the disintergrating planets K2-22 b (see section 2.1) and BD+05 4868 A b (Teq = 1820K, unknown Rp, cycle 4). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/A-Homogeneous.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
A Homogeneous Survey Of JWST MIRI Transmission Spectra Of 10 Exoplanets
[astro-ph.EP] The launch of JWST has enabled unprecedented atmospheric characterization of exoplanets. In particular, the JWST-MIRI instrument in the mid-infrared enables probing of molecular species that are harder to detect […]