- 1 Peer-reviewed papers from the MiARD project
- 2 Selected posters and conference presentations
- 3 Downloads
Peer-reviewed papers from the MiARD project
- Jean-Baptiste Vincent and colleagues have published the article Constraints on cometary surface evolution derived from a statistical analysis of 67P’s topography in Monthly Notices of the Royal Astronomical Society
- Raphael Marschall and colleagues have had the article Cliffs versus plains: Can ROSINA/COPS and OSIRIS data of comet 67P/Churyumov-Gerasimenko in autumn 2014 constrain inhomogeneous outgassing? accepted by Astronomy and Astrophysics in July 2017
- Nilda Oklay’s paper ‘Long term survival of surface water ice on comet 67P‘ was published by MNRAS in September 2017.
- In November 2017, Frank Preusker and colleagues have published a greatly improved shape model of comet 67P (coverage and resolution) The global meter-level shape model of comet 67P/Churyumov-Gerasimenko in Astronomy & Astrophysics.
- Tensile Strength of 67P/Churyumov-Gerasimenko Nucleus Material from Overhangs accepted for publication in Astronomy and Astrophysics in December 2017
- Thermal fracturing on comets. Applications to 67P/Churyumov-Gerasimenko, accepted for publication in Astronomy and Astrophysics in November 2017.
- On deviations from free-radial outflow in the inner coma of comet 67P/Churyumov-Gerasimenko, by Selina-Barbara Gerig of the University of Bern and other authors.
Selected posters and conference presentations
Yann Brouet and colleagues from the University of Bern and the German Aerospace Centre (DLR) prepared a poster on modelling the ‘brightness temperature’ of comet 67P/Churyumov-Gerasimenko. This is an important step in the MiARD project’s attempts to link observations of the comet to numerical models of its activity. The poster summarises attempts to reproduce microwave emissions measured by the MIRO instrument on the Rosetta spacecraft, and was presented at the February 2017 workshop on ‘Remote Sensing of Land, Ice & Snow’ organised by the European Association of Remote Sensing Laboratories.
This poster, presented by Chariton Christou at the 30th Scottish meeting on Fluid Mechanics in May 2017, describes the development of a new modelling approach to help understand the outgassing activity of comets. The new approach is based on modelling techniques used in the oil and gas exploration industry, and for this initial work uses porous terrestrial sandstones as analogue materials for a cometary surface (for this work the composition of the material is not important, just the porosity). Three-dimensional X-ray tomography images of the sandstones are used as inputs to the calculations.
This ‘3D rock file’ is the result of a CT scan (X-ray tomography) of a porous rock, by staff at Heriot-Watt University. On some platforms you can view and rotate it directly in your web-browser, otherwise it may be necessary to download it and use a viewer for .stl files. (‘Preview’ works on Macintosh computers).
This section contains links to a number of datasets generated by the project. In some cases the datasets are hosted elswhere.
VR viewer for the enhanced shape model of comet 67P
This VR Viewer for Windows for the enhanced shape model of comet 67P from the MiARD project uses a version of the high resolution model published by Preusker et al. ‘The global meter-level shape model of comet 67P/Churyumov-Gerasimenko‘, publication number 4 in the list above. To ease the computational burden, we used just 12 million facets, although the full model has 44 million facets. The viewer was built in Unity and can be used either with a normal PC screen, or in VR mode with an Oculus Rift headset.
To install the package, unzip the file linked above and save the resulting executable file along with the data folder in the same directory. Running the executable will start the viewer. If an Oculus Rift is connected, the viewer will automatically start in VR mode.
VIRTIS and MIRO ‘temperature’ maps
The origin of these VTK formatted data files is further explained in the MiARD D4.5 deliverable report “Mapping files of VIRTIS/MIRO data onto the 3D shape model“. These are rather large archives (1.6 Gb for the VIRTIS data, 0.8 Gb for the MIRO data). To view them, you will need software capable of opening VTK files (.vtu) such as Paraview.
VIRTIS radiance maps as .tar archive
MIRO temperature maps as .tar archive
Improved SPICE kernels for Rosetta position and orientation
Improved SPICE kernels derived during creation of the SHAP7 shape model for comet 67P within the MiARD project. SPICE kernels describe the position and orientation of objects in space (such as spacecraft, spacecraft instruments and comets) and are widely used in planetary science missions. Here is more information about ESA’s Rosetta SPICE kernels, and here is an introduction to the SPICE toolkit.
SHAP7 shape model of comet 67P/Churyumov-Gerasimenko
Pending archiving of the sub-meter accuracy SHAP7 space model (see Preusker et al 2017) in ESA and NASA repositories, it may be obtained on request from Frank.Preusker(at)dlr.de. See also http://europlanet.dlr.de/Rosetta/
Distribution in 3D of dust and gas
The MiARD project (in particular the University of Bern) has developed a numerical activity model for the outgassing and ejection of dust from the comet. The predictions of this model, for two sets of assumptions, are made available here. The data consists of 8 space separated ASCII files with seven columns of data. These seven columns (x, y, z, number density,u, v, w) are:
● x,y,z spatial coordinates in metres from centre of comet (Cheops reference frame)
● the number density of the gas or dust (m-3)
● u, v, w the x,y,z components of the velocity vector (m/s)
For each model (inhomogeneous or purely insolation driven) there is one file for the gas number density and velocity, and one file for each of the three dust particle sizes. The filenames should be self-explanatory. For more information, see the associated deliverable report.