ESA Science & Technology - Publication Archive
This internal final presentation has been prepared by the ESM/CDF team and summarizes the outcome of the ESM assessment study.
Contents of the presentation:
- Overview / Agenda
- System Presentation
- Payload Instruments (Telescope; Instruments; Detectors)
- Discipline presentations (AOCS; Configuration; Structures; Thermal; Propulsion; Power; DHS; GS/OPS; Communications; Programmatics; Risk)
Methods. We performed an extensive search for the counterparts of these selected All-Sky Survey objects in the NED and SIMBAD databases. Among 5176 selected objects, we found 4272 galaxies, 382 other extragalactic objects, 349 Milky Way stars, 50 other Galactic objects, and 101 sources detected before in various wavelengths but of an unknown origin. Twenty-two sources were left unidentified. Then, we checked the colors of stars and galaxies in the far-infrared flux-color and color-color plots.
Results. In the resulting diagrams, stars form two clearly separated clouds. One of them is easily distinguished from galaxies and allows for a simple method of excluding a large part of stars using the far-infrared data. The other smaller branch, overplotting galaxies, consists of stars known to have an infrared excess, like Vega and some fainter stars discovered by IRAS or 2MASS. The color properties of these objects in any case make them very difficult to distinguish from galaxies.
Conclusions. We conclude that the FIR color-color diagrams allow for a high-quality star-galaxy separation.With the proposed simple method we can select more that 95% of galaxies rejecting at least 80% of stars.
Abstract No. 1832
As a complement to Mars observations, Phobos spectral imaging was implemented in order to acquired compositional mapping with the prime objective to answer to the following questions:
- Is Phobos a "primitive" (undifferentiated) body, or is its mass sufficient for this small body to have suffered some degree of internal differentiation, so as to exhibit surface compositional variations reflecting variation with depth?
- Can one detect surface material containing either volatile or organic compounds ?
Abstract No. 2195
Of the many previous hypotheses concerning the origin of Phobos' grooves, most authorities agree that their formation is in some way connected with the creation of Stickney crater, at nearly 10 km diameter the largest crater on Phobos [1,2,3]. The principal argument for the Stickney association has been that the grooves form a pattern that is approximately radial to Stickney [1,2]. However, such hypotheses were based on incomplete mapping of the satellite, the largest poorly-imaged area being adjacent to Stickney's western rim. Much of the unknown region has now been imaged by HRSC, and we have assembled a new groove map from this and all other available imagery. The impression of grooves radial to Stickney can be seen to be an artefact of the previous coverage. East of Stickney this idea can be sustained, but west of it the pattern is tangential to the crater. The satellite-wide groove pattern can be seen to be centred not at Stickney, but at the leading apex of Phobos in its orbit (i.e. 90° long., 0° lat.). Groove orientations are quite independent of Stickney and bear no relation to it.