The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other planets.Scientific investigation began shortly after the advent of radio in the early 1900s, and focused international efforts have been ongoing since the 1980s. In 2015, Stephen Hawking and Russian billionaire Yuri Milner announced a project called Breakthrough Listen.
Context. Gas giant planets orbiting low-mass stars (T-eff less than or similar to 4600 K) are uncommon outcomes of planet formation. Increasing the sample of well-characterised giants around early M dwarfs will enable population-level studies of their properties, offering valuable insights into their formation and evolutionary histories. Aims. We aim to confirm and characterise giant exoplanets transiting M dwarfs identified by the TESS mission. To this end, we have started the Gas giAnts Transiting 1Ow-mass Stars (GATOS) programme within the NIRPS guaranteed time observations (GTO). Methods. High-resolution spectroscopic data were obtained in the optical and near-infrared (nIR), combining HARPS and NIRPS. We derived radial velocities (RVs) via the cross-correlation function and implemented a novel post-processing procedure to further mitigate telluric contamination in the nIR. The resulting RVs were jointly fit with TESS and ground-based photometry to derive the orbital and physical parameters of the systems. Results. We present the GATOS programme and its first results. We confirm two gas giants transiting the low-mass stars TOI-3288 A (K9V, T-eff = 3933 +/- 48 K) and TOI-4666 (M2.5V, T-eff = 3512 +/- 36 K). TOI-3288 A hosts a hot Jupiter with a mass of 2.11 +/- 0.08 M-Jup and a radius of 1.00 +/- 0.03 R-Jup, with an orbital period of 1.43 days (T-eq = 1059 +/- 20 K). TOI-4666 hosts a 0.70 +/- 0.06 M-Jup warm Jupiter (T-eq = 713 +/- 14 K) with a radius of 1.11 +/- 0.04 R-Jup, with an orbital period of 2.91 days. At a population level, we identify a decrease in planetary mass with spectral type, whereby late M dwarfs host less massive giant planets than early M dwarfs. More massive gas giants that deviate from this trend are preferentially hosted by more metal-rich stars. Furthermore, we find an increased binarity fraction among low-mass stars hosting gas giants, which may play a role in enhancing giant planet formation around low-mass stars. Conclusions. These mass characterisations contribute to the growing catalogue of well-defined giant exoplanets around low-mass stars. The observed population trends agree with theoretical predictions, whereby higher metallicity can compensate for lower disc masses, and wide binary systems may influence planet formation and migration through Kozai-Lidov cycles or disc instabilities.
The JPL rover Perseverance's investigations of Jezero crater's floor reveal that the ultramafic S & eacute;& iacute;tah formation and the overlying mafic M & aacute;az formation are deformed into a broad, low-amplitude structural dome. Mastcam-Z stereo images processed into digital outcrop models, together with RIMFAX ground-penetrating radar profiles, were used to reconstruct the three-dimensional stratal geometry of both units along a SW-NE transect across a southern domain of the dome called south S & eacute;& iacute;tah. Measurements from 3-D reconstructions show a progression from sub-horizontal layers in the central parts of the dome to dips <20 degrees away from the dome on its flanks, with M & aacute;az and underlying S & eacute;& iacute;tah layers dipping concordantly. RIMFAX profiles and imaging around the dome confirm that limb dips are continuous into the subsurface and form a flat-crested composite quaquaversal fold structure. S & eacute;& iacute;tah rocks in the fold core are up to 17 m higher than adjacent M & aacute;az lava flows, despite stratigraphically underlying them, a relationship attributed to structural uplift. Fold geometry, wavelength (similar to 1 km), and amplitude (similar to 30-50 m), match models of forced folding produced by inflation of shallow igneous intrusions. The most likely cause is the emplacement of a sill or laccolith beneath the crater floor, generating elastic bending of the overlying layers. This intrusion-driven uplift explains S & eacute;& iacute;tah's elevated position, constrains the deformation history of Jezero's crater floor units post-emplacement of the S & eacute;& iacute;tah and M & aacute;az formations, and supports a significant role for shallow magmatic intrusion in shaping intracrustal structures on Mars.
We present observations of the Uranian outer ring system at near-infrared and visible wavelengths. Observations with the Keck Telescope were taken in July-August 2007 at 2.12 and 1.63 mu m, when the ring plane was almost edge-on (ring opening angle -0.24). These data showed, for the first time, the mu ring at infrared wavelengths. NIRCam on the James Webb Space Telescope observed Uranus in 2023-2025 at wavelengths 1.4-4.8 mu m and 60-65. Hubble Space Telescope data were obtained between 2003 and 2013 at wavelengths 0.45-0.96 mu m and from to . We confirm that the mu ring is blue and the ring red. Both rings show strong absorption bands at 3 mu m; the mu ring also shows an emission peak at 3.6 mu m. Based upon a combination of the spectral slope and absorption/emission features, the mu ring must be composed of (sub-)micron-sized icy grains. The ring is a dusty ring rich in organics (similar to 10%-15% tholins). The radial profile of both rings is triangular, with an outward extension for the ring and inward for the mu ring. Both rings are optically thin; at 1.5 mu m for the mu ring and for the ring. Based upon the composition and radial extent of the rings we suggest the mu ring to originate via micrometeoroid impacts on the icy moon Mab, and the ring via collisions between, and micrometeoroid impacts on, parent non-icy bodies embedded within this ring.
On 24 April 2025 at 18:30:57 UTC, a bright daytime fireball over Southcentral Alaska was detected by 37 seismic stations, 16 single infrasound sensors, and four infrasound arrays, yielding 30 ballistic and multiple fragmentation arrivals. The unprecedented density of seismoacoustic coverage enabled detailed reconstruction of the event using acoustic signals, with fragmentation source locations further guiding the identification of Doppler weather radar signatures of a meteorite fall. Incorporation of a radar-derived terminal point yielded a final trajectory solution, which agreed closely with an independent optical trajectory solution from video analysis. The reconstructed entry parameters from seismoacoustic analysis indicate a velocity of 25.3 km/s, an entry angle of 19 degrees, and an energy release of similar to 38 t TNT equivalent. Assuming a chondritic composition, the pre-entry object diameter was similar to 0.7 m. Using orbital parameters from the optical solution, we estimate meteoroid composition as most likely an L-type ordinary chondrite. The event occurred in the sub-Arctic, where space-based optical systems face challenges in detection, demonstrating the critical role of dense ground-based seismoacoustic networks in characterizing high-latitude atmospheric entries. This uniquely well-recorded event demonstrates the capability of dense seismoacoustic networks to constrain bolide trajectories, energetics, and fragmentation, with radar and optical data providing critical confirmation and complementary perspectives. These results bridge the methodological gap between planetary-defense monitoring of natural impactors and space-traffic analyses of artificial reentries, illustrating how multi-sensor integration can deliver calibration-grade trajectories even for unpredicted events.
JWST has already observed near-infrared transmission spectra of over a dozen super-Earths and sub-Neptunes. While some observations have allowed astronomers to characterize sub-Neptunes in unprecedented detail, small feature amplitudes and poorly understood systematics have led to ambiguous results for others. Using the first seven targets from the COMPASS program, which will survey 12 small planets using NIRSpec/G395H, we investigate timeseries systematics. We implement a model that uses the principle components of the normalized pixel fluxes to account for variations in the shape and position of the spectral trace. We find that observations with a smaller number of groups-per-integration benefit most profoundly from the use of this model, and that systematics are particularly strong between 2.8 and 3.5 μ m. Despite these systematics, pandexo is a relatively accurate predictor of the precision of the spectra, with real error bars on average 5% larger in NRS1 and 12% larger in NRS2 than predicted. We compute new limits on metallicity and opaque pressure level for each target and compare these to previous results from the COMPASS program. Next, we coadd spectra from multiple targets to reduce the effective noise in the combined spectra in hopes of detecting transmission features in common between the targets, but this exercise does not yield compelling evidence of any signals. We find that a handful of additional transits are sufficient to break the degeneracy between metallicity and aerosols for the majority of our targets, pointing towards the possibility of unraveling the mysteries of these worlds with future allocations of JWST time.
