On the Utility of Transmission Color Analysis: Using color analysis of low-resolution transmission spectra to differentiate super-Earths from sub-Neptunes
Just a few specific near-infrared filters can be used to differentiate between super-Earths and sub-Neptunes, with ~93% accuracy for noise-free spectra
Newly Discovered ULF Periodicity of Daytime Auroral Pulsations
This study has provided direct evidence that compressional Pc5 ULF waves in the dayside outer magnetosphere determine the periodicity of daytime Pc5 diffuse auroral pulsations
Transmission Spectroscopy of the Earth-Sun System to Inform the Search for Extrasolar Life
A mission capable of observing Earth transiting the Sun can evaluate whether the transit technique is effective for detecting signs of habitability and life
New Insight into Radiation Belt Losses
New results from NASA’s Van Allen Probes have conclusively demonstrated the importance of magnetopause losses and outward transport during radiation belt dropout events
A living catalog of stream interaction regions in the Parker Solar Probe era
A new living catalog of SIRs has been created by the Parker Solar Probe team to better explore these large-scale structures
Multiscale Nature of the Magnetotail Reconnection Onset
Embedded electron and ion watersheds are important precursors of the magnetotail reconnection onset that also reveal its multiscale nature
Variable Irradiation on 1D Cloudless Eccentric Exoplanet Atmospheres
1D time stepping codes for atmospheric modeling of exoplanets are more complex than 1D equilibrium models, but can run much faster than 3D models!
Energetic Ions in the Venusian System: Insights from the First Solar Orbiter Flyby
Venus has a unique and complex space plasma environment. Better understanding this system provides insight intothe varieties of magnetospheres in our solar system and beyond
Statistical Evidence that Magnetic Reconnection Creates High-Energy Electrons
These MMS observations provide statistical evidence that active reconnection sites (i.e., “electron diffusion regions” or “EDRs”) in Earth’s magnetotail do produce very energetic particles
Venus Exploration in the New Human Spaceflight Age
Human flybys of Venus on the way to Mars provide new, unique science opportunities, and the time to begin coordinating such “Earth to Mars via Venus” missions is now.
Heliophysics 5-volume major reference set
With over 2,000 pages and 288 authors from 23 countries, this 5-volume work explains the drivers of space weather and the coupling of the geospace system.
A Campaign to Characterize the Volatile Chemistry of 46P/Wirtanen
46P/Wirtanen: Unprecedented compositional data from a ground-based infrared study
Evidence of highly-localized dispersionless particle injections inside GEO
The local presence or absence of deeply- penetrating DF fields can determine whether the concurrent injection inside GEO is a dispersionless or energy dispersed signature
On the Origin & Thermal Stability of Ices on Pluto & MU69
The New Horizons flybys found abundant, hyper-volatile CO, N2, and CH4at Pluto, but none at MU69, which is super-rich in CH3OH.
The Wave Curl Analysis Revealing Fundamental Properties of EMIC Waves
A newly developed technique based on closely-spaced multi-spacecraft measurements can now unlock critical information missing from our understanding of EMIC waves
The Enceladus Orbilander
A robust search for life on Enceladus can be accomplished with today’s technology.
Suprathermal particles from corotating interaction regions during the first perihelion pass of Solar Orbiter
Solar Orbiter observations provide unique insight into the radial dependence of CIR-associated suprathermal ions in the inner heliosphere
The Venus Life Equation
Venus Life Equation factors are estimated to be non-zero, yielding a probability for extant life of </= 0.1.
Ion acceleration associated with Io’s auroral tail
Concurrent observations of plasma waves suggest this is the first evidence of ion conics being generated via the electromagnetic coupling between Io and Jupiter.
Heavy ion charge states in Jupiter’s polar magnetosphere
1) ion-neutral interactions are playing a role in redistributing the heavy ion charge states; 2) these energetic heavy ions may be a source of Jupiter’s soft X-rays
New Illumination and Temperature Constraints of Mercury’s Volatile Polar Deposits
Portions of Mercury’s volatile polar deposits are dimly sunlit and experience maximum surface temperatures that are consistent with being comprised of macromolecular organic compounds.
What are Negative Injections in the Earth’s Magnetosphere?
Unique negative injections signatures in energetic particle data are the result of the same magnetospheric phenomenon we’ve been studying for decades, but under different conditions
Searching for Samples of the Lunar Mantle
Combining measurements in the near and mid infrared provides complementary, robust information about the mineralogy of the Moon’s surface
First high-resolution observations of an interplanetary shock
New observations of an interplanetary shock by NASA’s MMS mission have confirmed previously-theorized phenomena and enabled new insight into the small-scale physics of shocks
An Estimation of Human-Error Contributions to Historical Ionospheric Data
The variability due to human-scaling of radar ionograms can be very significant!
Diamonds in the Rough
Maps from Cassini INCA of the heliosphere from solar cycle 23 reveal how the solar cycle drives the structure of the outer heliosphere
Determining Lunar Basin Ages
Age-determination of impact melt from ancient lunar basins would provide insight into Earth’s early impact environment during the emergence of life.
Ice Giant Systems 2020
APL researchers played a major role in organizing and participating in this international workshop focused on future exploration of the Ice Giants
Earliest Use of the Term “Habitable Zone”?
E. Walter Maunder defined the habitable zone in a popular book published in 1913.
Where do magnetospheric ions come from and how are they energized?
New observations from NASA’s MMS mission find that ions observed in the magnetotail are often of solar wind origin – and that these higher charge ions more easily attain higher energies
Energetic particles in Saturn’s magnetosphere
Plasma injections can be used to quantify the flow of mass and energy in a magnetosphere.
Asteroid Bennu’s surface is like loose, dry sand
These OSIRIS-REx observations mean that resurfacing is frequent and that Bennu’s surface is ten times younger than previously believed.
Auroral Reconstruction CubeSwarm
ARCS 2019 MIDEX
Altitude-dependent nitrogen concentrations in Venus’ atmosphere
MESSENGER-measured neutron fluxes reveal higher amount of nitrogen gas by volume at altitudes >50 km than at low altitudes.
Active/Passive Multiple Polarization Sea Ice Detection
Automated ice detection based on a new, high-resolution, synergistic algorithm provides between factors of two and eight improvement in ice edge locations, relative to ground truth, over current autom
Simulating Artificial Lunar Atmospheres
Monitoring the lunar atmosphere during and after lunar landings can help in planning missions and can address outstanding science questions.
High-Latitude Ionospheric Variability measured from Antarctica
First-principles modeling accurately predicts a major form of Space Weather at high latitudes
A New Method For Studying Exoplanet Atmospheres
Planetary Infrared Excess (PIE) could revolutionize how we study exoplanet atmospheres.
Origin of Bennu and Ryugu
The asteroids Ryugu and Bennu are aggregates born from the disruption of a large parent asteroid.
Discovery of the Mechanism Behind Saturn’s Periodic Radio Emissions and Implications for Brown Dwarfs
Temperature anisotropy in energetic particle injections leads to the generation of upper hybrid plasma waves, which in turn converts to the periodic 5 kHz radio emissions
Ion acceleration at stream interaction regions (SIRs) observed by the extraordinary measurements of Parker Solar Probe (PSP)
Parker Solar Probe is unlocking the mysteries of particle acceleration within the inner heliosphere!
Solving the Mystery of Auroral Beads
First of its kind global magnetosphere simulation undertaken at t.he APL-led Center for Geospace Storms (CGS) connects the vastly disparate scales of auroral beads and the global magnetosphere to unra
Predictive capabilities of Stream Interaction Regions at Different Solar Longitudes
A multi-point, string-of-pearl type mission architecture would improve capabilities of capturing and predicting SIRs
Juno identifies three distinct auroral acceleration zones at Jupiter
It is greatly surprising that Zone-I and Zone-II can generate equally intense auroral emissions, contrary to expectations from Earth
Why Land on Mercury?
Mercury is the only major terrestrial body for which in situ surface data are lacking, yet the planet holds unique value in understanding how rocky worlds form and evolve.
Juno discovers persistent megavolt potentials over Jupiter’s polar caps
Downward megavolt potentials (1-10 MV) fill broad regions of Jupiter’s polar caps, poleward of Jupiter’s main aurora
Investigating the formation of iron meteorites through laboratory experiments
Lab experiments that mimic the chemistry of iron meteorites provide insight into the evolution of asteroids in the early Solar System
Substorm Energy Transport from the Magnetotail to the Nightside Ionosphere
The field-aligned energy transport in the plasma sheet and subsequent deposition into the poleward boundary of the auroral bulge is most critical for substorm energy budget
Solar Illumination Dependence of the Auroral Electrojet Intensity: Interplay between the Solar Zenith Angle and Dipole Tilt
The westward auroral electrojet is more intense, probably because of higher ionospheric conductance due to more intense auroral precipitation, when the ionosphere is dark than when it is sunlit.
Major Geochemical Terranes of Mercury's Northern Hemisphere
Although not mineralogically pure end?members, individual Principal Component maps are a measure of the relative variability of pyroxenes (PC1), plagioclase (PC2), and olivine (PC3).
Impact of Deep Local Dipolarization on Electron and Ion Pitch Angle Distributions
First statistical picture of the response of electron and ion PADs to local dipolarizations inside GEO
Using Gamma-ray and Neutron “Glasses” to Measure Phobos’ Elemental Composition
By measuring the composition of Phobos, MEGANE will help resolve the question of whether Phobos is a captured asteroid or the remnants of a giant impact into Mars.
The variable depth-to-diameter ratios of impact crater candidates on Bennu
Candidate impact craters on the tiny asteroid Bennu exhibit striking variation in depth-to-diameter ratios. These variations provides clues to the physical properties of this tiny asteroid and insight
APL Geospace Simulations at Hayden Planetarium
APL Simulations of the Geospace System Featured in a New Hayden Planetarium Show
Measuring hydrogen on Mercury using MESSENGER’s Gamma-Ray and Neutron Spectrometer
MESSENGER GRNS data reveal that more hydrogen exists in the subsurface at Mercury’s cold poles than Mercury’s hot poles.
Predicting the Geoeffective Properties of CMEs: Status, Open Issues, and Path Forward
Reliable Space Weather prediction requires targeted investment to improve observational and modeling capabilities and basic research
Probing Io’s Environment with Juno/JEDI
Io’s effect on the Jovian magnetosphere is likely mediated by wave-particle interactions.
Benchmarking Impact Hydrocodes for the DART Mission
When similar strength models are used across codes, variations in predictions for crater size and momentum enhancement from a kinetic impactor are within 15-20%.
Can EMIC waves be produced off the magnetic equator?
EMIC waves can be generated well away from the magnetic equator, given the right local conditions mainly found in the outer magnetosphere.
Anomalous Clay-Bearing Outcrop South of Valles Marineris, Mars
The identification of Fe/Mg-bearing clay layers above Al-clays means that aqueous weathering on early Mars involved multiple events and/or processes.
Energetic Oxygen and Sulfur Charge States in the Outer Jovian Magnetosphere: Insights from the Cassini Jupiter Flyby
These results indicate a charge-dependent heating/energization or an energy dependence of the charge state abundance in the outer magnetosphere of Jupiter.
How much of Mt. Sharp was fluvial?
Volume balance calculations indicate that mechanisms other than flowing water are required to account for the majority of sediments transported into Gale crater, Mars.
Understanding the Structure of the Solar Corona
Individual Images available to the public at http://sd-www.jhuapl.edu/secchi/wavelets/
Know before you go: Lunar seasons produce dynamic thermal environment in polar regions
Plans for exploration in seasonally shadowed regions should consider seasonal effects on frost stability, subsurface ice stability, and trafficability.
Solar Wind Entry Into the Magnetosphere
New APL-built model for the first time simultaneously captures both proposed mechanisms of solar wind plasma entry into the magnetosphere and suggests an explanation for the observed dawn-dusk asymme
Dragonfly: A mission to explore organic chemistry and habitability on Saturn’s moon Titan
Dragonfly will explore an ocean world to determine how far chemistry has progressed in environments providing key ingredients for life
Composition of Suprathermal Ions in Corotating Interaction Regions
The composition of CIRs exhibits clear correlation with solar activity
Don’t Judge The Moon By It’s Cover:Getting Beneath the Surface with Radar
Radar can detect variations in roughness that reveal otherwise difficult to observe features.
Contribution of bursty bulk flows to the global dipolarization of the magnetotail during an isolated substorm
Dungey cycle at work: Global substorm dipolarization of the nightside magnetosphere is an accumulation of localized geomagnetic field enhancements carried by bursty plasma flows
The largest asteroids are likely icy objects
Instead of being most similar to carbonaceous chondrites, a detailed study of large asteroids’ composition finds them to differ from those meteorites and be similar to icy asteroids like Ceres and The
Ionospheric O+ ion outflow “off the beaten path”
First observations of ionospheric O+ ion outflow directly into the nightside inner magnetosphere from an equatorial vantage point.
Comet 45P – A case of nature vs. nurture
Comet 45P retains its primitive character despite intense heating and erosion
Rocket Investigation of Current Closure in the Ionosphere (RICCI): A novel application of CubeSats from a sounding rocket platform
The RICCI mission concept uses the novel deployment of multiple CubeSats as miniature ?sub-payloads to obtain the first direct in-situ measurement of ionospheric closure currents.
Cosmic-ray Irradiation Experiments with Iron Meteorites
Psyche Gamma-Ray and Neutron Spectrometer measurements of cosmic-ray activation products are a new technique for deriving surface composition from orbit.
Defining Expected Science Value from Missions
Probabilistic science value metrics defined using information theory and operations research enable the quantification of potential “science value” of potential spacecraft missions.
The influence of collisions on ion dynamics in the inner comae of four comets
Collisions between ions and neutrals in the inner coma of a comet reduce the ion velocity and result in chemistry that changes the composition of the ions
Empirical Modeling of Extreme Space Weather Events: Storm-Time Geomagnetic Field, Electric Current, and Plasma Pressure
Application of modern data-mining and machine-learning techniques to the largest spaceborne magnetometer database enables reconstruction of the magnetic field, current and plasma pressure distributio
Floor-fractured craters on Ceres: Cryovolcanism or Solid State Flow?
New models suggest that some of Ceres' fractures on crater floors may have formed due to solid state flow of a low-viscosity, low-density material.
Is there a Europa neutral torus?
Yes, Europa is producing a neutral torus
Recent innovations at the JHUAPL Planetary Impact Lab
The JHU/APL Planetary Impact Lab developed an 3D-printed sabot for use in high-velocity gun experiments, an innovation that provides significant mass and cost savings compared to sabots manufactured u
Low Energy Precipitating Electrons in the Diffuse Aurorae
High fluxes of low energy electrons observed by the DMSP can be attributed to the secondary electrons that bounce between the conjugate points in the ionosphere.
Areas With Unusual Ultraviolet SignaturesDiscovered on the Moon
Investigation of anomalous FUV regions may help in the understanding of lunar surface processes, including the formation of lunar swirls.
3D Reconstruction of Coronal Mass Ejections (CMEs) and Their Shocks
Multi-viewpoint coronal imaging allows the extraction of the 3D properties of CMEs and shocks and the assessment of their potential for Space Weather.
Mars: Composition Beneath the Dust
Composition of the youngest rocks are comparable to intermediate-aged volcanic terrain. The mostancient volcanic material is compositionally distinct, suggesting early igneous evolution of the crust.
Measuring Earth radiation with the RAVAN CubeSat
RAVAN demonstrates new technologies that enable future Earth radiation budget (ERB) measurements and establishes a benchmark for an ERB small satellite constellation.
Storm-Driven Rebuilding and Intensification of Earth's Radiation Belt
Geomagnetic storms can act as a "reset" button for the outer radiation belt. At storm onset, the existing outer belt is largely annihilated and a new, more intense belt is rebuilt. New APL-built mode
Bennu asteroid map
OSIRIS-REx explores why asteroid Bennu doesn't break apart?
What is the Origin of Daytime Auroral Pulsations?
Daytime Pc3 auroral pulsations are directly linked to upstream-generated compressional Pc3 waves and their modulations of chorus waves and keV electrons in the outer magnetosphere
Small Body Mapping Tool
Make your own asteroid maps!
Mercury: The view after MESSENGER
Compendium of Science from MESSENGER Just Published!
How many near-Earth asteroids have water in their minerals?
Water on asteroids is more accessible than water on the moon.
Recurrent Formation of a Dawnside Electric Current System During Geomagnetic Storms
An intense auroral current system forms recurrently on the dawn side during major geomagnetic storms causing large magnetic disturbances at midlatitudes.
The First Multi-Viewpoint Catalog of Coronal Mass Ejection (CME) Properties
The first-ever ‘stereoscopic’ catalog of CME properties (based on simultaneous 2 viewpoint observations from the STEREO mission).
The Dynamics of Crater Ejecta Emplacement
Crater ejecta slides violently away from the crater after landing, eroding and shearing the surface and subsurface to significant depths.
High-Energy Particle Transport and Acceleration at Earth
Magnetic trapping enables transport and energization of energetic ions and relativistic electrons deep into the near-Earth space
The case for seasonal surface changes at Titan's lake district
Titan’s north polar lakes experience seasonal shoreline change.
Sources of Plasma at Saturn
Two important processes contribute to solar wind particle entry into the magnetosphere of Saturn
The curious case of a missing meteoritic signature
Two impact craters in Canada formed in nearly identical targets have starkly different meteoritic signatures.
Improved Lunar Prospector Neutron Spectrometer Map
Reconstruction of Lunar Prospector thermal neutron data reveal 100 km sized regions of nearly pure anorthosite in basins on the lunar farside.
What can Apollo soil samples tell us about the Moon’s environment?
The physical, chemical, and spectral properties of lunar agglutinates hold clues about the space weathering processes that formed them.
Modeling impact outcomes for the Double Asteroid Redirection Test (DART) Mission
Material porosity and internal structure can significantly affect crater shape, ejecta field, and momentum enhancement from a kinetic impactor.
Wind-sculpted Landscape on Olympus Mons, Mars
The Olympus Maculae reveal multiple episodes of wind-driven deposition and erosion, suggesting fluctuating atmospheric conditions in the Late Amazonian.
Antarctica Balloon Flight Tests New Science Instruments
High-altitude balloon flights provide a cost-effective means to test planetary gamma-ray and neutron spectrometers in a space-like radiation environment.
A proxy for solar wind conditions near Mars
The proxy we derive for magnetic field direction upstream of Mars will be useful when MAVEN’s orbit gets lowered such that it goes into the solar wind less often.
Projectile preservation during oblique impacts
Oblique impacts significantly enhance projectile preservation. The results suggest a new strategy for sample return missions that rely on impact capture. Moreover, our findings imply that M-type aster
Red sand, Blue sand
The color of sand on Mars’ dunes depends on grain size, composition, and oxidation state.
The delivery of water by impacts
Water delivered by impactors can be trapped in significant quantities within impact glasses and melt-bearing breccias, thereby contributing to the early accretion of water during planet formation.
Methane Rain Clouds at Titan
Titan's weather patterns suggest liquid methane reservoirs below the surface near Titan's poles.
Atmospheric drag is eroding Saturn’s inner ring
More than ten tons of molecules and small neutral particles every second are flowing into Saturn from its rings because of the interaction between Saturn’s atmosphere and the rings.
How did Mercury get its ice?
The Hokusai impact could be the source of Mercury’s water ice.
Investigating the Ages of Mercury’s Explosive Volcanic Deposits
Explosive volcanism on Mercury extended into Recent Geologic History, well after the presumed cessation of volcanic activity early in Mercury’s history.
Asteroid shapes from disruption and reaccumulation
Energetic disruption and reaccumulation produces top-shaped asteroids. More elongated asteroids like Eros and Itokawa form less commonly.
MESSENGER Advanced Products (MEAPs)
The MESSENGER Advanced Product (MEAP) project enhances the utility of MESSENGER data from the planet Mercury to the planetary science community.
Identifying buried, compositionally-distinct materials on Mars using gamma-ray measurements
Gamma-ray measurements can reveal the presence of compositionally-distinct deposits buried several 10s of cm below Mars’ surface.
Prebiotic Molecules Storage in Comets
The remarkable chemical diversity of comets reflects the range of conditions in the early Solar System
The APL Planetary Impact Lab
The APL Planetary Impact Lab (PIL) includes a Vertical Gun Range and Ejecta Catapult that enable state-of-the-art studies of impact cratering processes.
Mapping Ice at Mercury’s South Pole
The uneven distribution of Mercury’s ice supports a comet impact origin
An exogenic origin for Iapetus’ ridge
A collapsing disk of debris could build topography to create a ridge around Iapetus
Impact Melting on Vesta at the Rheasilvia Antipode
Giant impact melting may have prolonged igneous activity on protoplanets
Effect of Re-impacting Debris on the Solidification of the Lunar Magma Ocean
Debris generated after the Moon-forming impact would have re-impacted the Moon, introducing additional heat transfer mechanisms to the conventional conductive-lid scenario.
Mercury’s Dark Secret
Low Reflectance Material on Mercury is enriched in carbon, and is native to Mercury.
Evidence for volatiles on the surface of 433 Eros and 1036 Ganymed
We have detected hydrated minerals on the two largest near-Earth asteroids, expected to be anhydrous. They likely are delivered by external sources such as solar wind or dust.
A Fresh Look at Older Mars Odyssey Neutron Spectrometer Data Yields a Surprise at the Equator
An improved-resolution map of the MONS epithermal neutron data was created and reveals substantial, unexpected H deposits near the equator.
Mars: Destroyer of Sand Dunes
Mars’ current climate may be eroding away the most upwind sand dunes