S. F. Hviid
A5069403689- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Space Exploration and Technology
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Geology and Paleoclimatology Research
- Astronomical and nuclear sciences
- Space Science and Extraterrestrial Life
- Atmospheric Ozone and Climate
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Spacecraft and Cryogenic Technologies
- Spaceflight effects on biology
- Solar and Space Plasma Dynamics
- Geological and Geochemical Analysis
- Geochemistry and Geologic Mapping
- Gamma-ray bursts and supernovae
- Spacecraft Design and Technology
- Radioactive Decay and Measurement Techniques
- High-pressure geophysics and materials
- Nuclear physics research studies
- Scientific Research and Discoveries
- Image Processing and 3D Reconstruction
- Geophysics and Gravity Measurements
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2005-2024
Planet
2013-2024
Institut für Lungenforschung
2015-2019
Max Planck Institute for Solar System Research
2007-2017
Max Planck Society
2005-2017
University of Potsdam
2017
European Space Research and Technology Centre
2017
University of Bern
2016
John Wiley & Sons (United States)
2015
Osservatorio Astronomico di Padova
2005-2015
Spirit landed on the floor of Gusev Crater and conducted initial operations soil‐covered, rock‐strewn cratered plains underlain by olivine‐bearing basalts. Plains surface rocks are covered wind‐blown dust show evidence for enrichment soluble species as vein void‐filling materials coatings. The is result a minor amount transport deposition aqueous processes. Layered granular deposits were discovered in Columbia Hills, with outcrops that tend to dip conformably topography. interpreted be...
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and nearby plains within Meridiani Planum. soils consist of fine-grained basaltic sand a surface lag hematite-rich spherules, spherule fragments, other granules. Wind ripples are common. Underlying thin soil layer, exposed small impact craters troughs, flat-lying sedimentary rocks. These rocks finely laminated, rich sulfur, contain abundant sulfate salts. Small-scale cross-lamination some locations...
Phoenix Ascending The mission landed on Mars in March 2008 with the goal of studying ice-rich soil planet's northern arctic region. included a robotic arm, camera attached to it, capacity excavate through ice layer beneath scoop up and water samples, deliver them combination other instruments—including wet chemistry lab high-temperature oven combined mass spectrometer—for chemical geological analysis. Using this setup, Smith et al. (p. 58 ) found at depths 5 15 centimeters, Boynton 61...
The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. is hypothesized be the of former lake, but no clear evidence for lacustrine sedimentation has found date. Instead, dominant lithology basalt, geologic processes are impact events eolian transport. Many rocks exhibit coatings other characteristics that may minor aqueous alteration. Any sediments exist at this location within apparently buried by lavas undergone...
Images from the OSIRIS scientific imaging system onboard Rosetta show that nucleus of 67P/Churyumov-Gerasimenko consists two lobes connected by a short neck. The has bulk density less than half water. Activity at distance Sun >3 astronomical units is predominantly neck, where jets have been seen consistently. rotates about principal axis momentum. surface morphology suggests removal larger volumes material, possibly via explosive release subsurface pressure or creation overhangs sublimation,...
Critical measurements for understanding accretion and the dust/gas ratio in solar nebula, where planets were forming 4.5 billion years ago, are being obtained by GIADA (Grain Impact Analyser Dust Accumulator) experiment on European Space Agency's Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 3.4 astronomical units inbound, OSIRIS (Optical, Spectroscopic, Infrared Remote Imaging System) detected 35 outflowing grains of mass 10(-10) to 10(-7) kilograms, 48 10(-5)...
Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard European Space Agency’s Rosetta spacecraft at scales better than 0.8 meter per pixel show a wide variety different structures textures. The data importance airfall, surface dust transport, mass wasting, insolation weathering for cometary evolution, they offer some support subsurface fluidization models loss through ejection large chunks material.
The Philae lander, part of the Rosetta mission to investigate comet 67P/Churyumov-Gerasimenko, was delivered cometary surface in November 2014. Here we report precise circumstances multiple landings Philae, including bouncing trajectory and rebound parameters, based on engineering data conjunction with operational instrument data. These also provide information mechanical properties (strength layering) surface. first touchdown site, Agilkia, appears have a granular soft (with compressive...
We analyzed more than 200 OSIRIS NAC images with a pixel scale of 0.9−2.4 m/pixel comet 67P/Churyumov-Gerasimenko (67P) that have been acquired from onboard the Rosetta spacecraft in August and September 2014 using stereo-photogrammetric methods (SPG). derived improved position pointing data for high-resolution shape model consists about 16 million facets (2 m horizontal sampling) typical vertical accuracy at decimeter scale. From this model, we derive volume northern hemisphere 9.35 km3 ±...
Context. The complex shape of comet 67P and its oblique rotation axis cause pronounced seasonal effects. Irradiation hence activity vary strongly.
Context. We investigate the formation and evolution of comet nuclei other trans-Neptunian objects (TNOs) in solar nebula primordial disk prior to giant planet orbit instability foreseen by Nice model.
ABSTRACT The Rosetta probe, orbiting Jupiter-family comet 67P/Churyumov–Gerasimenko, has been detecting individual dust particles of mass larger than 10 −10 kg by means the GIADA collector and OSIRIS Wide Angle Camera Narrow since 2014 August will continue until 2016 September. Detections single allow us to estimate anisotropic flux from 67P, infer loss rate size distribution at surface sunlit nucleus, see whether 67P evolves in time. velocity orbiter, relative is much lower measured GIADA,...
Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil dust at the Sagan Memorial Station during course its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral elemental data, use along with previous Viking, SNC meteorite, telescopic results, to help constrain origin evolution Martian dust. find that soils can be divided into least eight distinct spectral units, based parameterization Imager for (IMP) 400...
A spacecraft flyby of an asteroid reveals a high-density body that is more like planetesimal than rubble pile.
The Mars Exploration Rover Opportunity touched down at Meridiani Planum in January 2004 and since then has been conducting observations with the Athena science payload. rover traversed more than 5 km, carrying out first outcrop‐scale investigation of sedimentary rocks on Mars. are sandstones formed by eolian aqueous reworking sand grains that composed mixed fine‐grained siliciclastics sulfates. siliciclastic fraction was produced chemical alteration a precursor basalt. sulfates dominantly...
The objective of the Phoenix mission is to determine if Mars' polar region can support life. Since liquid water a basic ingredient for life, as we know it, an important goal exists at landing site. It believed that layer Martian soil preserves ice by forming barrier against high temperatures and sublimation, but exposed sublimates without formation phase. Here show possible independent physical thermodynamical evidence besides ice, saline in areas disturbed Lander. Moreover, thermodynamics...
Aims. The OSIRIS camera onboard the Rosetta spacecraft has been acquiring images of comet 67P/Churyumov-Gerasimenko (67P)'s nucleus at spatial resolutions down to ~0.17 m/px ever since Aug. 2014. These have yielded unprecedented insight into morphological diversity comet's surface. This paper presents an overview regional morphology 67P.
Context. We present an investigation of the surface properties areas on nucleus comet 67P/Churyumov-Gerasimenko.
Context. The Rosetta mission of the European Space Agency has been orbiting comet 67P/Churyumov-Gerasimenko (67P) since August 2014 and is now in its escort phase. A large complement scientific experiments designed to complete most detailed study a ever attempted are onboard Rosetta.
We study the link between gravitational slopes and surface morphology on nucleus of comet 67P/Churyumov-Gerasimenko provide constraints mechanical properties cometary material. computed for five regions that are representative different morphologies observed surface, using two shape models from OSIRIS images by stereo-photoclinometry (SPC) stereo-photogrammetry (SPG) techniques. estimated tensile, shear, compressive strengths considerations. The show a similar general pattern in terms...
During its 2 yr mission around comet 67P/Churyumov–Gerasimenko, ESA's Rosetta spacecraft had the unique opportunity to follow closely a in most active part of orbit. Many studies have presented typical features associated with activity nucleus, such as localized dust and gas jets. Here, we report on series more energetic transient events observed during 3 months surrounding comet's perihelion passage 2015 August. We detected characterized 34 outbursts cameras, one every 2.4 nucleus...