Search Publications
Detection of Rotational Acceleration of Bennu Using HST Light Curve Observations
Emery, J. P.; Chesley, S. R.; Noll, K. S. +7 more
We observed the near-Earth asteroid (101955) Bennu from the ground in 1999 and 2005, and with the Hubble Space Telescope (HST) in 2012, to constrain its rotation rate. The data reveal an acceleration of 2.64 ± 1.05 × 10-6 deg/day2, which could be due to a change in the moment of inertia of Bennu or to spin up from the Yarkovs…
On the Relation Between Jovian Aurorae and the Loading/Unloading of the Magnetic Flux: Simultaneous Measurements From Juno, Hubble Space Telescope, and Hisaki
Kurth, W. S.; Bagenal, F.; Yoshioka, K. +20 more
We present simultaneous observations of aurorae at Jupiter from the Hubble Space Telescope and Hisaki, in combination with the in situ measurements of magnetic field, particles, and radio waves from the Juno Spacecraft in the outer magnetosphere, from 80RJ to 60RJ during 17 to 22 March 2017. Two cycles of accumulation and rel…
Alfvén Wave Propagation in the Io Plasma Torus
Bagenal, F.; Bonfond, B.; Hinton, P. C.
Io, the most volcanically active body in the solar system, fuels a plasma torus around Jupiter with dissociation products of SO2 at a rate of 1,000 kg/s. We use a combination of in situ Voyager 1 data and Cassini Ultraviolet Imaging Spectrograph observations to constrain a diffusive equilibrium model of the Io plasma torus. The interact…
C-Complex Asteroids: UV-Visible Spectral Characteristics and Implications for Space Weathering Effects
Vilas, Faith; Hendrix, Amanda R.
Space weathering effects on the rocky S-class asteroids are well understood. However, on the low-albedo C-complex asteroids, such as spacecraft targets Bennu and Ryugu, the situation is more complicated, especially due to a lack of spectral features throughout the visible-near infrared spectral region. Here we show, through a combination of observ…
Jovian Auroral Radio Sources Detected In Situ by Juno/Waves: Comparisons With Model Auroral Ovals and Simultaneous HST FUV Images
Kurth, W. S.; Lamy, L.; Zarka, P. +4 more
Since the discovery of Jovian auroral radio emissions, the question arises of the source positions of the different components (broadband kilometric, hectometric, and decametric) and their association with far ultraviolet (FUV) auroral emissions. We surveyed Juno's first 15 perijoves to track local radio sources from in situ Juno/Waves measurement…
Formation of a New Great Dark Spot on Neptune in 2018
Simon, A. A.; Wong, M. H.; Hsu, A. I.
For the first time, Hubble Space Telescope visible-wavelength imaging shows the formation history of a dark vortex on Neptune. A new northern Great Dark Spot (NDS-2018) was discovered in September and November 2018 images, spanning roughly 12° of latitude and 27° in longitude (11,000 × 5,000 km) at 23°N planetographic latitude. NDS-2018 is similar…
Jovian High-Latitude Ionospheric Ions: Juno In Situ Observations
Thomsen, M. F.; Wilson, R. J.; Louarn, P. +10 more
The low-altitude, high-velocity trajectory of the Juno spacecraft enables the Jovian Auroral Distributions Experiment to make the first in situ observations of the high-latitude ionospheric plasma. Ions are observed to energies below 1 eV. The high-latitude ionospheric ions are observed simultaneously with a loss cone in the magnetospheric ions, s…
Wave Activity in Jupiter's North Equatorial Belt From Near-Infrared Reflectivity Observations
Wong, Michael H.; Irwin, Patrick G. J.; Orton, Glenn S. +4 more
High spatial resolution images of Jupiter at 1.58-2.28 µm are used to track and characterize a wave pattern observed in 2017 at a planetocentric latitude of 14°N. The wave pattern has a wave number of 18 and spans ∼5° in latitude. One bright crest remains stationary in System III longitude, while the remaining crests move slowly westward. Th…