Search Publications
Compositional variations of Titan's impact craters indicates active surface erosion
Janssen, M. A.; Cassini Radar Team; Werynski, A. +2 more
Titan, the only moon in the solar system with a considerable atmosphere, is host to a variety of exogenic processes that shape its surface. These processes form features that are quite similar to features on Earth, including sand dunes, rivers, and lakes. The combination of a thick atmosphere and active surface processes also leads to a scarcity o…
Constraints on Uranus's haze structure, formation and transport
Wong, Michael H.; Irwin, Patrick G. J.; Teanby, Nicholas A. +4 more
Microphysical simulations have been performed to constrain the formation and structure of haze in Uranus's atmosphere. These simulations were coupled to a radiative-transfer code to fit observations performed by the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) and by the Wide Field Camera 3 (WFC3) of the Hubble Space …
Spatial and seasonal variations in C3Hx hydrocarbon abundance in Titan's stratosphere from Cassini CIRS observations
Lombardo, Nicholas A.; Nixon, Conor A.; Achterberg, Richard K. +4 more
Of the C3Hx hydrocarbons, propane (C3H8) and propyne (methylacetylene, CH3C2H) were first detected in Titan's atmosphere during the Voyager 1 flyby in 1980. Propene (propylene, C3H6) was first detected in 2013 with data from the Composite InfraRed Spectrometer …
Seasonal formation rates of martian slope streaks
Jaumann, R.; Hiesinger, H.; Kreslavsky, M. +3 more
Slope streaks are gravity-driven dark or light-toned features that form throughout the martian year in high-albedo and low-thermal inertia equatorial regions on Mars. These distinctive features have never been observed in a terrestrial environment although some analogs have been proposed. Based on diverse orbital observations, a number of mechanis…
Evidence for color dichotomy in the primordial Neptunian Trojan population
Smith, M.; D'Andrea, C. B.; Abbott, T. M. C. +45 more
In the current model of early Solar System evolution, the stable members of the Jovian and Neptunian Trojan populations were captured into resonance from the leftover reservoir of planetesimals during the outward migration of the giant planets. As a result, both Jovian and Neptunian Trojans share a common origin with the primordial disk population…
The volume of water required to carve the martian valley networks: Improved constraints using updated methods
Head, James W.; Rosenberg, Eliott N.; Palumbo, Ashley M. +2 more
The martian valley networks are a key piece of evidence for the presence of liquid water on early Mars, and understanding their formation conditions can provide valuable insight into the nature of the early climate. Previous studies have used various methods to estimate the volume of water required to carve the valley networks, with results rangin…
Student Dust Counter: Status report at 38 AU
Stern, S. A.; Szalay, J. R.; Spencer, J. +8 more
The Student Dust Counter (SDC) is an in-situ dust detector aboard the New Horizons spacecraft observing the distribution of interplanetary dust particles (IDPs) with mass >10-12 g or approximately 0.5 µm in radius. New Horizons was launched on January 19th, 2006 and performed a fly-by of the Pluto system on July 14th, 2015. SDC…
The visual spectrum of Jupiter's Great Red Spot accurately modeled with aerosols produced by photolyzed ammonia reacting with acetylene
Baines, K. H.; Sromovsky, L. A.; Carlson, R. W. +2 more
We report results incorporating the optical properties of the red-tinted photochemically-generated aerosols of Carlson et al. (2016, Icarus 274, 106-115) in spectral models of Jupiter's Great Red Spot (GRS). This material - created in laboratory GRS simulations from acetylene reacting with photolytic products of ammonia produced by 0.2-µm ra…
Present-day development of gully-channel sinuosity by carbon dioxide gas supported flows on Mars
Massé, Marion; Conway, Susan J.; Vincendon, Mathieu +7 more
Martian gullies have been widely studied, but their formation mechanism is still under debate. Their channels generally trend straight downslope, but some display sinuosity. Seasonally active gullies are common on sand dunes and their channels have been reported to develop sinuosity. Here, we perform a detailed analysis of a gully on a dune within…
The HST lightcurve of (486958) 2014 MU69
Stern, S. A.; Buie, M. W.; Spencer, J. R. +6 more
We report Hubble Space Telescope (HST) lightcurve observations of the New Horizons spacecraft encounter Kuiper Belt object (KBO) (486958) 2014 MU69 acquired near opposition in July 2017. In order to plan the optimum flyby sequence the New Horizons mission planners needed to learn as much as possible about the target in advance of the en…