Search Publications

Discovery of a bright quasar without a massive host galaxy

Wisotzki, Lutz; Jablonka, Pascale; Courbin, Frédéric +4 more

A quasar is thought to be powered by the infall of matter onto a supermassive black hole at the centre of a massive galaxy. Because the optical luminosity of quasars exceeds that of their host galaxy, disentangling the two components can be difficult. This led in the 1990s to the controversial claim of the discovery of `naked' quasars. Since then,…

High-velocity streams of dust originating from Saturn

Grün, Eberhard; Kempf, Sascha; Srama, Ralf +5 more

High-velocity submicrometre-sized dust particles expelled from the jovian system have been identified by dust detectors on board several spacecraft. On the basis of periodicities in the dust impact rate, Jupiter's moon Io was found to be the dominant source of the streams. The grains become positively charged within the plasma environment of Jupit…

No oceans on Titan from the absence of a near-infrared specular reflection

West, R. A.; Brown, M. E.; Roe, H. G. +2 more

With its substantial atmosphere of nitrogen, hydrocarbons and nitriles, Saturn's moon Titan is a unique planetary satellite. Photochemical processing of the gaseous constituents produces an extended haze that obscures the surface. Soon after the Voyager fly-bys in 1980 and 1981 photochemical models led to the conclusion that there should be enough…

How Prometheus creates structure in Saturn's F ring

Porco, Carolyn C.; Burns, Joseph A.; Murray, Carl D. +4 more

Images of Saturn's narrow and contorted F ring returned by the Cassini spacecraft have revealed phenomena not previously detected in any planetary ring system. The perturbing effect of the inner shepherding satellite, Prometheus, seems to introduce channels through the F ring and a `streamer'-a line of particles that link the ring to the satellite…

Planetary science: Huygens rediscovers Titan

Owen, Tobias

The first analyses of data sent by the Huygens probe from Saturn's largest moon Titan are flooding in. They paint a picture of a `Peter Pan' world - potentially like Earth, but with its development frozen at an early stage.

Planetary science: Are there active glaciers on Mars?

Montgomery, David R.; Gillespie, Alan R.; Mushkin, Amit

Magnetospheric physics: Turbulence on a small scale

Goldstein, Melvyn L.

The four-spacecraft Cluster mission has identified small-scale vortices in Earth's magnetosphere. The observation reveals processes that transfer energy and momentum from the solar wind to the magnetosphere.

Planetary science: Are there active glaciers on Mars? (Reply)

Jaumann, R.; Head, J. W.; Neukum, G. +11 more

Gillespie et al. concur with our interpretation that certain lobate equatorial and mid-latitude features on Mars are due to debris-covered glaciers formed largely during past periods of increased spin-axis obliquity, when climate regimes favoured snow and ice accumulation and glacial flow. They suggest that the `hourglass' deposit, dated at more t…

Planetary science: The impact of Deep Impact

Feldman, Paul D.

A good look at the Deep Impact cometary encounter was taken by the Rosetta mission, itself on the way to a rendezvous with a comet in 2014. So what is a comet - icy dustball or dusty iceball?

Titan team claims just deserts as probe hits moon of crème brûlée

Abbott, Alison