Search Publications
The properties of Titan's surface at the Huygens landing site from DISR observations
Keller, H. U.; Küppers, M.; Schröder, S. E. +3 more
The descent imager/spectral radiometer (DISR) onboard the Huygens probe investigated the radiation balance inside Titan's atmosphere and took hundreds of images and spectra of the ground during the descent. The scattering of the aerosols in the atmosphere and the absorption by methane strongly influence the irradiation reaching the surface and the…
Venus upper atmosphere winds from ground-based heterodyne spectroscopy of CO 2 at 10µm wavelength
Sornig, M.; Livengood, T.; Sonnabend, G. +4 more
We report observations of Venus atmospheric wind near 110 km altitude by means of high-resolution mid-infrared spectroscopy. Data were acquired May 28-June 4, 2007 at the McMath-Pierce Solar Telescope (Kitt Peak, Arizona, USA), during a coordinated ground-based observing campaign in support of Venus Express. The Cologne Tuneable Heterodyne Infrare…
The reflectance spectrum of Titan's surface at the Huygens landing site determined by the descent imager/spectral radiometer
Keller, H. U.; Schröder, S. E.
The descent imager/spectral radiometer aboard the Huygens probe successfully acquired images and spectra of the surface of Titan. To counter the effects of haze and atmospheric methane absorption it carried a surface science lamp to illuminate the surface just before landing. We reconstruct the reflectance spectrum of the landing site in the 500-1…
Influence of high abundances of aerosols on the electrical conductivity of the Titan atmosphere
Whitten, R. C.; Borucki, W. J.
Observations of optical depth and scattering by instrumentation onboard the Huygens probe have been used by Tomasko et al. [Tomasko et al., 2005. Rain, winds and haze during Huygens probe's descent to Titan's surface. Nature 438 (8), 765-778] to deduce that the size and abundance of Titan aerosols could be nearly independent of altitude. Here we s…
The imaging performance of the SRC on Mars Express
Williams, D.; Jaumann, R.; Oberst, J. +14 more
The Mars Express spacecraft carries the pushbroom scanner high-resolution stereo camera (HRSC) and its added imaging subsystem super resolution channel (SRC). The SRC is equipped with its own optical system and a 1024×1024 framing sensor. SRC produces snapshots with 2.3 m ground pixel size from the nominal spacecraft pericenter height of 250 km, w…
Monitoring Venus’ mesospheric winds in support of Venus Express: IRAM 30-m and APEX observations
Lellouch, E.; Moreno, R.; Moullet, A. +1 more
We report on direct wind measurements in Venus' mesosphere (90-115 km), performed in support of Venus Express, and based on CO millimeter observations. Most observations, sampling the CO(2-1) and CO(1-0) lines, were acquired with the IRAM 30-m telescope, over four distinct periods: (i) Summer 2006; (ii) May-June 2007, in association with the coord…
Field-aligned currents and parallel electric field potential drops at Mars. Scaling from the Earth’ aurora
Woch, J.; Dubinin, E.; Fraenz, M. +1 more
The observations of electron inverted 'V' structures by the MGS and MEX spacecraft, their resemblance to similar events in the auroral regions of the Earth, and the discovery of strong localized magnetic field sources of the crustal origin on Mars, raised hypotheses on the existence of Martian aurora produced by electron acceleration in parallel e…
Mesospheric vertical thermal structure and winds on Venus from HHSMT CO spectral-line observations
Hartogh, Paul; Jarchow, Christopher; Rengel, Miriam
We report vertical thermal structure and wind velocities in the Venusian mesosphere retrieved from carbon monoxide ( 12CO J=2-1 and 13CO J=2-1) spectral line observations obtained with the Heinrich Hertz Submillimeter Telescope (HHSMT). We observed the mesosphere of Venus from two days after the second Messenger flyby of Venu…
X-rays from Venus observed with Chandra
Dennerl, Konrad
X-ray observations of Venus are so challenging that the first detection of Venusian X-rays succeeded only in January 2001, with the Chandra satellite. The X-rays from Venus were found to result from fluorescent scattering of solar X-rays in the Venusian thermosphere. An additional component, caused by charge exchange of highly charged heavy ions i…
Identification of a new outflow channel on Mars in Syrtis Major Planum using HRSC/MEx data
Mangold, N.; Neukum, G.; Hiesinger, H. +6 more
Syrtis Major Planum is a volcanic plain dominated by lava flows. High resolution stereo camera (HRSC) images of the northern Syrtis Major region display erosional features such as grooves, teardrop-shaped islands and valleys. These landforms are characteristics of outflow channels seen on Mars, therefore implying that a flood event took place in t…