Explore the vast range of titles available.

After his three best friends die in a car crash when he should have been driving, seventeen-year-old Tucker meets Charon, the Ferryman of Hades, and must decide whether to succumb to his grief or go on living.

Since 2010, nationwide networks of reference centers for sarcomas (RREPS/NETSARC/RESOS) collected and prospectively reviewed all cases of sarcomas and connective tumors of intermediate malignancy (TIM) in France. The nationwide incidence of sarcoma or TIM (2013-2016) was measured using the 2013 WHO classification and confirmed by a second independent review by expert pathologists. Simple clinical characteristics, yearly variations and correlation of incidence with published clinical trials are presented and analyzed. Over 150 different histological subtypes are reported from the 25172 patients with sarcomas (n = 18712, 74,3%) or TIM (n = 6460, 25.7%), with n = 5838, n = 6153, n = 6654, and n = 6527 yearly cases from 2013 to 2016. Over these 4 years, the yearly incidence of sarcomas and TIM was therefore 70.7 and 24.4 respectively, with a combined incidence of 95.1/106/year, higher than previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of tumors. Only GIST, as a single entity had a yearly incidence above 10/106/year. There were respectively 30, 64 and 66 different histological subtypes of sarcomas or TIM with an incidence ranging from 10 to 1/106, 1-0.1/106, or < 0.1/106/year respectively. The 2 latter incidence groups represented 21% of the patients with 130 histotypes. Published phase III and phase II clinical trials (p<10-6) are significantly higher with sarcomas subtypes with an incidence above 1/106 per. This nationwide registry of sarcoma patients, with exhaustive histology review by sarcoma experts, shows that the incidence of sarcoma and TIM is higher than reported, and that tumors with a very low incidence (1<106/year) are less likely to be included in clinical trials.

The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions with other Kuiper belt objects (KBOs) with diameters from ∼40 kilometers to ∼300 meters, smaller than most KBOs observed directly by telescopes. We find a relative paucity of small craters ≲13 kilometers in diameter, which cannot be explained solely by geological resurfacing. This implies a deficit of small KBOs (≲1 to 2 kilometers in diameter). Some surfaces on Pluto and Charon are likely ≳4 billion years old, thus their crater records provide information on the size-frequency distribution of KBOs in the early Solar System.

The flyby of Pluto and its moon Charon by the New Horizons spacecraft generated news coverage around the world. Now Stern et al. report the first scientific results from the high-speed encounter. The surface of Pluto is surprisingly diverse, with large regions of differing brightness and composition. There is ample evidence for ongoing rich geological processes that act to sculpt its surface. Charon's surface is similarly complex, with numerous relief structures and varied coloration. Pluto's atmosphere is extensive but less dense than expected, whereas Charon has no detectable atmosphere. Science , this issue p. 10.1126/science.aad1815 The first scientific results from New Horizon’s flyby of Pluto reveal a rich and diverse geology. The Pluto system was recently explored by NASA’s New Horizons spacecraft, making closest approach on 14 July 2015. Pluto’s surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto’s atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto’s diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto’s large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected.

Newly processed global imaging and topographic mapping of Uranus's five major satellites reveal differences and similarities to mid-sized satellites at Saturn and Pluto. Three modes of internal heat redistribution are recognized. The broad similarity of Miranda's three oval resurfacing zones to those mapped on Enceladus and (subtly) on Dione are likely due to antipodal diapiric upwelling. Conversely, break-up and foundering of crustal blocks accompanied by extensive (cryo)volcanism is the dominant mode on both Charon and Ariel. Titania's fault network finds parallels on Rhea, Dione, Tethys and possibly Oberon. Differences in the geologic style of resurfacing in the satellite systems (e.g. plains on Charon, Dione, Tethys and perhaps Titania versus ridges on Miranda and Ariel) may be driven by differences in ice composition. Surface processes such as volatile transport may also be indicated by bright and dark materials on Oberon, Umbriel and Charon. The more complete and higher quality observations of the Saturnian and Plutonian mid-sized icy satellites by Cassini and New Horizons reveal a wealth of features and phenomena that cannot be perceived in the more limited Voyager coverage of the Uranian satellites, harbingers of many discoveries awaiting us on a return to Uranus. This article is part of a discussion meeting issue ‘Future exploration of ice giant systems'.

This report continues the practice where the IAU Working Group on Cartographic Coordinates and Rotational Elements revises recommendations regarding those topics for the planets, satellites, minor planets, and comets approximately every 3 years. The Working Group has now become a “functional working group” of the IAU, and its membership is open to anyone interested in participating. We describe the procedure for submitting questions about the recommendations given here or the application of these recommendations for creating a new or updated coordinate system for a given body. Regarding body orientation, the following bodies have been updated: Mercury, based on MESSENGER results; Mars, along with a refined longitude definition; Phobos; Deimos; (1) Ceres; (52) Europa; (243) Ida; (2867) Šteins; Neptune; (134340) Pluto and its satellite Charon; comets 9P/Tempel 1, 19P/Borrelly, 67P/Churyumov–Gerasimenko, and 103P/Hartley 2, noting that such information is valid only between specific epochs. The special challenges related to mapping 67P/Churyumov–Gerasimenko are also discussed. Approximate expressions for the Earth have been removed in order to avoid confusion, and the low precision series expression for the Moon’s orientation has been removed. The previously online only recommended orientation model for (4) Vesta is repeated with an explanation of how it was updated. Regarding body shape, text has been included to explain the expected uses of such information, and the relevance of the cited uncertainty information. The size of the Sun has been updated, and notation added that the size and the ellipsoidal axes for the Earth and Jupiter have been recommended by an IAU Resolution. The distinction of a reference radius for a body (here, the Moon and Titan) is made between cartographic uses, and for orthoprojection and geophysical uses. The recommended radius for Mercury has been updated based on MESSENGER results. The recommended radius for Titan is returned to its previous value. Size information has been updated for 13 other Saturnian satellites and added for Aegaeon. The sizes of Pluto and Charon have been updated. Size information has been updated for (1) Ceres and given for (16) Psyche and (52) Europa. The size of (25143) Itokawa has been corrected. In addition, the discussion of terminology for the poles (hemispheres) of small bodies has been modified and a discussion on cardinal directions added. Although they continue to be used for planets and their satellites, it is assumed that the planetographic and planetocentric coordinate system definitions do not apply to small bodies. However, planetocentric and planetodetic latitudes and longitudes may be used on such bodies, following the right-hand rule. We repeat our previous recommendations that planning and efforts be made to make controlled cartographic products; newly recommend that common formulations should be used for orientation and size; continue to recommend that a community consensus be developed for the orientation models of Jupiter and Saturn; newly recommend that historical summaries of the coordinate systems for given bodies should be developed, and point out that for planets and satellites planetographic systems have generally been historically preferred over planetocentric systems, and that in cases when planetographic coordinates have been widely used in the past, there is no obvious advantage to switching to the use of planetocentric coordinates. The Working Group also requests community input on the question submitting process, posting of updates to the Working Group website, and on whether recommendations should be made regarding exoplanet coordinate systems.

Charon, Pluto’s largest moon, has been extensively studied, with research focusing on its primitive composition and changes due to radiation and photolysis. However, spectral data have so far been limited to wavelengths below 2.5 μm, leaving key aspects unresolved. Here we present the detection of carbon dioxide (CO 2 ) and hydrogen peroxide (H 2 O 2 ) on the surface of Charon’s northern hemisphere, using JWST data. These detections add to the known chemical inventory that includes crystalline water ice, ammonia-bearing species, and tholin-like darkening constituents previously revealed by ground- and space-based observations. The H 2 O 2 presence indicates active radiolytic/photolytic processing of the water ice-rich surface by solar ultraviolet and interplanetary medium Lyman- α photons, solar wind, and galactic cosmic rays. Through spectral modeling of the surface, we show that the CO 2 is present in pure crystalline form and, possibly, in intimately mixed states on the surface. Endogenically sourced subsurface CO 2 exposed on the surface is likely the primary source of this component, with possible contributions from irradiation of hydrocarbons mixed with water ice, interfacial radiolysis between carbon deposits and water ice, and the implantation of energetic carbon ions from the solar wind and solar energetic particles. Due to the limited wavelength coverage of measurements to date, some aspects of the composition of Pluto’s largest moon, Charon, remain unresolved. Here, the authors detect carbon dioxide and hydrogen peroxide on the surface of Charon’s northern hemisphere using JWST data.

Following its flyby and first imaging of the Pluto–Charon binary, the New Horizons spacecraft visited the Kuiper belt object (KBO) 2014 MU 69 (also known as (486958) Arrokoth). The imaging showed MU 69 to be a contact binary that rotates at a low spin period (15.92 hours), is made of two individual lobes connected by a narrow neck and has a high obliquity (about 98 degrees) 1 , properties that are similar to those of other KBO contact binaries inferred through photometric observations 2 . However, all scenarios suggested so far for the origins of such configurations 3 – 5 have failed to reproduce these properties and their probable frequent occurrence in the Kuiper belt. Here we show that semi-secular perturbations 6 , 7 operating on only ultrawide KBO binaries close to their stability limit can robustly lead to gentle, slow binary mergers at arbitrarily high obliquities but low rotational velocities, reproducing the characteristics of MU 69 and other similar oblique contact binaries. Using N -body simulations, we find that approximately 15 per cent of all ultrawide binaries with a cosine-uniform inclination distribution 5 , 9 are likely to merge through this process. Moreover, we find that such mergers are sufficiently gentle to deform the shape of the KBO only slightly. The semi-secular contact binary formation channel not only explains the observed properties of MU 69 , but may also apply to other Kuiper belt or asteroid belt binaries and in the Solar System and extra-solar moon systems. The high obliquity and low rotation period of the Kuiper belt object (2014) MU 69 and other similar contact binaries is successfully reproduced from the collision and post-collision characteristics of initially wide binaries.

Pluto and Charon are the largest binary system in the known population of trans-Neptunian objects in the outer Solar System. Their shared external orbital axis suggests a linked evolutionary history and collisional origin. Their radii, ~1,200 km and ~600 km, respectively, and Charon’s wide circular orbit of about 16 Pluto radii require a formation mechanism that places a large mass fraction into orbit, with sufficient angular momentum to drive tidal orbital expansion. Here we numerically model the collisional capture of Charon by Pluto using simulations that include material strength. In our simulations, friction distributes impact momentum, leading Charon and Pluto to become temporarily connected, instead of merging, for impacts aligned with the target’s rotation. In this ‘kiss-and-capture’ regime, coalescence of the bodies is prevented by strength. For a prograde target rotation consistent with the system angular momentum, Charon is then tidally decoupled and raised into a near-circular orbit from which it migrates outwards to distances consistent with its present orbit. Charon is captured relatively intact in this scenario, retaining its core and most of its mantle, which implies that Charon could be as ancient as Pluto. Numerical simulations suggest that Pluto’s moon Charon was captured intact, in a scenario in which the two bodies temporarily merged in a collision but did not coalesce due to solid strength effects.

Volatile organic compounds (VOCs) react with atmospheric oxidants, resulting in oxygenated products of lower volatility known as semi-volatile and intermediate-volatility organic compounds (S/IVOCs), which form secondary organic aerosols (SOAs). Those compounds can partition between the gas and particle phases, a critical process that is influenced by several environmental parameters yet is poorly constrained. This study aims to evaluate the effect of temperature and the VOC/NOx ratio on SOA formation and the partitioning of individual SOA products from m-xylene and naphthalene OH oxidation. Experiments are carried out in an oxidation flow reactor (OFR), and products are identified and quantified using a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) coupled to a CHemical Analysis of aeRosol ONline (CHARON) inlet. Results show that lower temperatures significantly enhance SOA formation, while lower VOC/NOx ratios reduce it. Gas-phase m-xylene major products are C3, C5, and C8 compounds, whereas particle–product distributions exhibit a progressive increase from C2 to C8. In contrast, naphthalene products partition more readily into the condensed phase, with C8–C10 products dominating. Most of the oxidation products from both precursors exhibit a volatility distribution in the SVOC regime, with fewer in the IVOC regime. The decrease in temperature shifts the effective saturation concentration (Ci∗) values towards lower values, although no clear relationship between Ci∗ and the oxidation state is observed. A comparison between observed and estimated volatilities using a model based on the group contribution method (SIMPOL.1) reveals systematic deviations for both light molecules and heavy compounds, suggesting a need for improved predictive models.