Search Publications
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…
Anti-planetward auroral electron beams at Saturn
Livi, S.; Krupp, N.; Dougherty, M. K. +10 more
Strong discrete aurorae on Earth are excited by electrons, which are accelerated along magnetic field lines towards the planet. Surprisingly, electrons accelerated in the opposite direction have been recently observed. The mechanisms and significance of this anti-earthward acceleration are highly uncertain because only earthward acceleration was t…
High-redshift galaxy populations
Cowie, Lennox L.; Hu, Esther M.
We now see many galaxies as they were only 800 million years after the Big Bang, and that limit may soon be exceeded when wide-field infrared detectors are widely available. Multi-wavelength studies show that there was relatively little star formation at very early times and that star formation was at its maximum at about half the age of the Unive…
The sequestration of ethane on Titan in smog particles
Hunten, D. M.
Saturn's largest satellite, Titan, has a dense atmosphere of nitrogen with a few per cent of methane. At visible wavelengths its surface is hidden by dense orange-brown smog, which is produced in the stratosphere by photochemical reactions following the dissociation of methane by solar ultraviolet light. The most abundant of the products of these …
Astrochemistry: Complex organic matter in Titan's aerosols?
Biemann, K.
Astrochemistry: Complex organic matter in Titan's aerosols? (Reply)
Steller, M.; Atreya, S. K.; Owen, T. +19 more
Biemann et al. calls into question our preliminary interpretations of our experimental results. A comparison of laboratory and flight measurements should settle the uncertainties he raises. In addition to evaluating instrumental characteristics such as the 'piston effect', a technique we used for injecting oven-gas content for gas chromatography-m…
Planetary science: Titan's exotic weather
Griffith, Caitlin A.
Titan is viewed as a sibling of Earth, as both bodies have rainy weather systems and landscapes formed by rivers. But as we study these similarities, Titan emerges as an intriguingly foreign world.
Planetary science: Saturn's bared mini-moons
Schmidt, Jürgen; Spahn, Frank
Propeller-shaped structures seem to reveal the presence of moonlets, about 100 metres in diameter, embedded in Saturn's rings. This discovery adds to our picture of how the rings formed and are evolving.
Space Physics: Breaking through the lines
Paschmann, Götz
Magnetic field lines are known to reorganize themselves in plasmas, converting magnetic to particle energy. Evidence harvested from the solar wind implies that the scale of the effect is larger than was thought.