Reducing the False-Positive Rate for Isovalerylcarnitine in Expanded Newborn Screening: The Application of a Second-Tier Test

Abstract The isodecyl neopentanoate is an ingredient used in the cosmetic industry to prepare a nipple fissure balm. We report on 12 newborns that showed elevated C5-acylcarnitine levels upon newborn screening following treatment with balm. The first 3 neonates were immediately recalled for confirmatory tests and resulted negative for both isovaleric acidemia and short/branched chain acyl-CoA dehydrogenase deficiency. In the other 9 cases, the immediate recall was avoided by applying a new second-tier test able to confirm the presence of pivaloylcarnitine. The concentration of C5-acylcarnitine was measured in the days following the suspension of balm application. Abnormal concentrations of C5-acylcarnitine did not seem to be associated with free carnitine deficiency, probably due to the short time of exposure. A direct correlation between balm ingestion and the elevation in pivaloylcarnitine has been demonstrated in 10 adult volunteers. The commercial balm containing a pivalic acid derivative is causal of false-positive results during newborn screening, and it could have the potential to cause secondary carnitine deficiency when used chronically

Multidisciplinary Analysis of Lermontov Crater on Mercury

We present the geological, age determination, and spectrophotometric analysis of the Lermontov Crater on Mercury

DART Impact Ejecta Plume Evolution: Implications for Dimorphos

The NASA Double Asteroid Redirection Test (DART) spacecraft impacted the moon Dimorphos of the [65803] Didymos binary system and changed the binary orbit period, demonstrating asteroid deflection by a kinetic impact and indicating that more momentum was transferred to Dimorphos by escaping impact ejecta than was incident with DART. Images of the DART impact ejecta plume were obtained by the Light Italian cubesat for Imaging of Asteroids (LICIACube) in the first few minutes after the DART impact. The ejecta plume imaged by LICIACube 158 s after the DART impact prior to closest approach shows no evidence for plume clearing at low altitude. The ejecta plume imaged 175 s after the DART impact is optically thick up to projected altitudes of 200 m above the surface of Dimorphos. These observations are compared with models of the impact ejecta plume optical depth, structure, and evolution, which are developed from point-source scaling models fitted to numerical simulations of the DART impact into a rubble pile Dimorphos with different material strengths. The observations of the impact plume optical depth and the high momentum transfer from the DART impact are not consistent with impact and ejecta plume models assuming the Dimorphos cohesive strength to be as high as 5000 Pa. Models with 5 and 50 Pa Dimorphos cohesive strength provide the overall best consistency with plume opacity observations and high momentum transfer

VADER: Probing the Dark Side of Dimorphos with LICIACube LUKE

The ASI cubesat LICIACube has been part of the first planetary defense mission DART, having among its scopes to complement the DRACO images to better constrain the Dimorphos shape. LICIACube had two different cameras, LEIA and LUKE, and to accomplish its goal, it exploited the unique possibility of acquiring images of the Dimorphos hemisphere not seen by DART from a vantage point of view, in both time and space. This work is indeed aimed at constraining the tridimensional shape of Dimorphos, starting from both LUKE images of the nonimpacted hemisphere of Dimorphos and the results obtained by DART looking at the impacted hemisphere. To this aim, we developed a semiautomatic Computer Vision algorithm, named VADER, able to identify objects of interest on the basis of physical characteristics, subsequently used as input to retrieve the shape of the ellipse projected in the LUKE images analyzed. Thanks to this shape, we then extracted information about the Dimorphos ellipsoid by applying a series of quantitative geometric considerations. Although the solution space coming from this analysis includes the triaxial ellipsoid found by using DART images, we cannot discard the possibility that Dimorphos has a more elongated shape, more similar to what is expected from previous theories and observations. The result of our work seems therefore to emphasize the unique value of the LICIACube mission and its images, making even clearer the need of having different points of view to accurately define the shape of an asteroid.This work was supported by the Italian Space Agency (ASI) within the LICIACube project (ASI-INAF agreement AC No. 2019-31-HH.0) and by the DART mission, NASA contract 80MSFC20D0004

The Dimorphos ejecta plume properties revealed by LICIACube

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.This work was supported by the Italian Space Agency (ASI) in the LICIACube project (ASI-INAF agreement AC no. 2019-31-HH.0) and by the DART mission, NASA contract 80MSFC20D0004. M.Z. acknowledges Caltech and the Jet Propulsion Laboratory for granting the University of Bologna a licence to an executable version of MONTE Project Edition software. M.Z. is grateful to D. Lubey, M. Smith, D. Mages, C. Hollenberg and S. Bhaskaran of NASA/JPL for the discussions and suggestions regarding the operational navigation of LICIACube. G.P. acknowledges financial support from the Centre national d’études spatiales (CNES, France). A.C.B. acknowledges funding by the NEO-MAPP project (grant agreement 870377, EC H2020-SPACE-2019) and by the Ministerio de Ciencia Innovación (PGC 2018) RTI2018-099464-B-I00. F.F. acknowledges funding from the Swiss National Science Foundation (SNSF) Ambizione (grant no. 193346). J.-Y.L. acknowledges the support from the NASA DART Participating Scientist Program (grant no. 80NSSC21K1131). S.D.R. and M.J. acknowledge support from the Swiss National Science Foundation (project no. 200021_207359)

Possible explosion crater origin of small lake basins with raised rims on Titan

The Cassini mission discovered lakes and seas comprising mostly methane in the polar regions of Titan. Lakes of liquid nitrogen may have existed during the epochs of Titan’s past in which methane was photochemically depleted, leaving a nearly pure molecular nitrogen atmosphere and, thus, far colder temperatures. The modern-day small lake basins with sharp edges have been suggested to originate from dissolution processes, due to their morphological similarity to terrestrial karstic lakes. Here we analyse the morphology of the small lake basins that feature raised rims to elucidate their origin, using delay-Doppler processed altimetric and bathymetric data acquired during the last close flyby of Titan by the Cassini spacecraft. We find that the morphology of the raised-rim basins is analogous to that of explosion craters from magma–water interaction on Earth and therefore propose that these basins are from near-surface vapour explosions, rather than karstic. We calculate that the phase transition of liquid nitrogen in the near subsurface during a warming event can generate explosions sufficient to form the basins. Hence, we suggest that raised-rim basins are evidence for one or more warming events terminating a nitrogen-dominated cold episode on Titan

Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos

The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defence, intended to validate kinetic impact as a means of asteroid deflection. Here we report a determination of the momentum transferred to an asteroid by kinetic impact. On the basis of the change in the binary orbit period2, we find an instantaneous reduction in Dimorphos’s along-track orbital velocity component of 2.70 ± 0.10 mm s−1, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact3,4. For a Dimorphos bulk density range of 1,500 to 3,300 kg m−3, we find that the expected value of the momentum enhancement factor, β, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg m−3, β=3.61−0.25+0.19(1σ). These β values indicate that substantially more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth

Properties of Rubble-Pile Asteroid (101955) Bennu from OSIRIS-REx Imaging and Thermal Analysis

Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images and thermal data from NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft, we show that asteroid (101955) Bennu's surface is globally rough, dense with boulders, and low in albedo. The number of boulders is surprising given Bennu's moderate thermal inertia, suggesting that simple models linking thermal inertia to particle size do not adequately capture the complexity relating these properties. At the same time, we find evidence for a wide range of particle sizes with distinct albedo characteristics. Our findings imply that ages of Bennu's surface particles span from the disruption of the asteroid's parent body (boulders) to recent in situ production (micrometre-scale particles)