Search Publications
Transiting extrasolar planetary candidates in the Galactic bulge
Brown, Thomas M.; Casertano, Stefano; Livio, Mario +13 more
More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to reflex motions of their host stars, and more recently through transits of some planets across the faces of the host stars. The detection of planets with the shortest known periods, 1.2-2.5 days, has mainly result…
A regular period for Saturn's magnetic field that may track its internal rotation
Russell, C. T.; Dougherty, M. K.; Smith, E. J. +1 more
The rotation rate of a planet is one of its fundamental properties. Saturn's rotation, however, is difficult to determine because there is no solid surface from which to time it, and the alternative `clock'-the magnetic field-is nearly symmetrically aligned with the rotation axis. Radio emissions, thought to provide a proxy measure of the rotation…
A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt
Stern, S. A.; Weaver, H. A.; Mutchler, M. J. +6 more
The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 × 10-4 and 1 × 10-5 of Pluto's mass, and between 5 × 10-3 and 1 × 10-4 of Charon's mass. This discovery, combined with the constraints on the absence of more distant sa…
Methane storms on Saturn's moon Titan
Hueso, R.; Sánchez-Lavega, A.
The presence of dry fluvial river channels and the intense cloud activity in the south pole of Titan over the past few years suggest the presence of methane rain. The nitrogen atmosphere of Titan therefore appears to support a methane meteorological cycle that sculptures the surface and controls its properties. Titan and Earth are the only worlds …
Rapid evolution of the most luminous galaxies during the first 900million years
Illingworth, Garth D.; Bouwens, Rychard J.
The first 900 million years (Myr) to redshift z ~ 6 (the first seven per cent of the age of the Universe) remains largely unexplored for the formation of galaxies. Large samples of galaxies have been found at z ~ 6 (refs 1-4) but detections at earlier times are uncertain and unreliable. It is not at all clear how galaxies built up from the first s…
Titan Radar Mapper observations from Cassini's T3 fly-by
Stiles, B.; Kelleher, K.; Callahan, P. +32 more
Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial cha…
100-metre-diameter moonlets in Saturn's A ring from observations of ‘propeller’ structures
Dones, Luke; Porco, Carolyn C.; Hedman, Matthew M. +5 more
Saturn's main rings are composed predominantly of water-ice particles ranging between about 1centimetre and 10metres in radius. Above this size range, the number of particles drops sharply, according to the interpretation of spacecraft and stellar occultations. Other than the gap moons Pan and Daphnis (the provisional name of S/2005 S1), which hav…
Suppression of dwarf galaxy formation by cosmic reionization
Loeb, Abraham; Wyithe, J. Stuart B.
A large number of faint galaxies, born less than a billion years after the Big Bang, have recently been discovered. Fluctuations in the distribution of these galaxies contributed to a scatter in the ionization fraction of cosmic hydrogen on scales of tens of megaparsecs, as observed along the lines of sight to the earliest known quasars. Theoretic…
No signature of clear CO2 ice from the `cryptic' regions in Mars' south seasonal polar cap
Forget, F.; Bibring, Jean-Pierre; Langevin, Yves +5 more
The seasonal polar ice caps of Mars are composed mainly of CO2 ice. A region of low (< 30%) albedo has been observed within the south seasonal cap during early to mid-spring. The low temperature of this `cryptic region' has been attributed to a clear slab of nearly pure CO2 ice, with the low albedo resulting from absorptio…
MARSIS radar sounder evidence of buried basins in the northern lowlands of Mars
Stofan, Ellen R.; Clifford, Stephen M.; Safaeinili, Ali +7 more
A hemispheric dichotomy on Mars is marked by the sharp contrast between the sparsely cratered northern lowland plains and the heavily cratered southern highlands. Mechanisms proposed to remove ancient crust or form younger lowland crust include one or more giant impacts, subcrustal transport by mantle convection, the generation of thinner crust by…