Radar mapping of Mercury's polar anomalies

  title={Radar mapping of Mercury's polar anomalies},
  author={John K. Harmon and Martin A. Slade and R. Velez and Arturo Crespo and Murray Dryer and J. M. Johnson},
GROUND-based radar observations of Mercury have revealed unusually strong, highly depolarized echoes from the north1,2 and south2 poles. These anomalous echoes have been cited as evidence of polar ice deposits1–5. Thermal studies3–5 suggest that the permanently shaded floors of large polar craters are cold enough to preserve water ice in a stable state over aeons, in spite of Mercury's proximity to the Sun. Here we present high-resolution radar maps of Mercury's polar regions, derived from… 
Investigating Mercury's South Polar Deposits: Arecibo Radar Observations and High‐Resolution Determination of Illumination Conditions
New Arecibo radar observations of Mercury's south pole are presented, which reveal numerous radar-bright deposits and substantially increase the radar imaging coverage, and images from MESSENGER's full mission are used to determine the illumination conditions ofMercury's south polar region at the same spatial resolution as the north polar region, enabling comparisons between the two poles.
High-Resolution Radar Imaging of Mercury's North Pole
Abstract The recently upgraded Arecibo S-band (λ12.6-cm) radar was used to make delay-Doppler images of Mercury's north polar region, where earlier observations had shown strong echoes from putative
Areas of permanent shadow in Mercury's south polar region ascertained by MESSENGER orbital imaging
Radar‐bright features near Mercury's poles have been postulated to be deposits of water ice trapped in cold, permanently shadowed interiors of impact craters. From its orbit about Mercury, MESSENGER
How Thick Are Mercury's Polar Water Ice Deposits?
Arecibo S-band Radar Characterization of Local-scale Heterogeneities within Mercury’s North Polar Deposits
Ground-based planetary radar observations first revealed deposits of potentially nearly pure water ice in some permanently shadowed regions (PSRs) on Mercury’s poles. Later, the MESSENGER spacecraft
Radar Imaging of Mercury
Abstract Earth-based radar has been one of the few, and one of the most important, sources of new information about Mercury during the three decades since the Mariner 10 encounters. The emphasis


The Thermal Stability of Water Ice at the Poles of Mercury
Thermal model calculations show that, despite Mercury's proximity to the sun, the temperatures of flat, low-reflectivity surfaces at Mercury's poles are not expected to exceed 167 kelvin, which is consistent with the presence of water ice.
Mercury Radar Imaging: Evidence for Polar Ice
The first unambiguous full-disk radar mapping of Mercury at 3.5-centimeter wavelength, with the Goldstone 70-meter antenna transmitting and 26 antennas of the Very Large Array receiving, has provided
Radar Mapping of Mercury: Full-Disk Images and Polar Anomalies
A random-code technique used at Arecibo to obtain delay-Doppler radar images of the full disk of Mercury revealed anomalously bright features at the north and south poles and a variety of more subdued reflectivity features ranging in size from hundreds to thousands of kilometers.
Mercury: Full-disk radar images and the detection and stability of ice at the North Pole
The first full-disk radar images of Mercury were obtained on August 8 and 23, 1991. These images were constructed using the Very Large Array (VLA) in Socorro, New Mexico, to receive and map radar
Radar Images of Mars
Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density, revealing near-surface features including a region in the Tharsis volcano area that displayed no echo to the very low level of the radar system noise.
Europa, Ganymede, and Callisto - New radar results from Arecibo and Goldstone
Observations of the icy Galilean satellites, conducted during 1987–1991 with the Arecibo 13-cm system and the Goldstone 3.5-cm system, yield significant improvements in our knowledge of the
Surface Coordinates and Cartography of Mercury.
A control net of Mercury has been established photogrammetrically by using the Mariner 10 pictures; coordinates of 1328 points are given. The Mariner 10 coordinate system uses a system of longitudes