964 research outputs found
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Characterisation of the UV environment of the Beagle 2 landing site
A study of the UV environment of the Beagle 2 landing site has been carried out. An instrument to measure the UV flux is present on the lander, and this work serves to aid in the interpretation of expected data
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MP3 - A meteorology and physical properties package to explore air-sea interaction on Titan
The exchange of mass, heat and momentum at the air:sea interface are profound influences on the terrestrial environment, affecting the intensity of hurricanes, the size of waves and lake-effect precipitation. Titan presents us with an opportunity to study these processes in a novel physical context, with a different sea, atmosphere and gravity. The MP3 instrument, under development for the proposed Discovery mission TiME (Titan Mare Explorer [1,2]) is an integrated suite of small, simple sensors that combines the function of traditional meteorology packages with liquid physical properties and depth-sounding : these latter functions follow the concept of - and indeed use spare elements from - the Huygens Surface Science Package (SSP,[3]). However, unlike Huygens’ brief and dynamic 3 hours of measurement, in TiME’s 6-Titan-day (96 Earth day) nominal mission enabled by radioisotope power, MP3 will have an unprecedented long-term measurement opportunity in one of the most evocative environments in the solar system, Titan’s sea Ligeia Mare
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Constraints on the Huygens landing site topography from the Surface Science Package Acoustic Properties Instrument
We present analysis of the results from the Huygens acoustic sounder instrument. The sounder sees a relatively smooth terrain, with specular reflectance characteristics
Observations of low luminosity X-ray sources in Vela-Puppis
Results of a study of the X-ray emission from a small portion of the galactic plane near galactic longitude 260 deg are presented. This region contains at least six low luminosity X-ray sources within approximately 10 deg. of PSRO833-45, which is near the center of the Gum Nebula. The X-ray source associated with the Vela pulsar, 4U0833-45, is observed at twice its 4U catalogue intensity. The lack of X-ray pulsations at the pulsar period, the non thermal power law spectrum, and models of the X-ray come from an extended source approximately 1 deg in radius. The observation of a high temperature spectrum in a field of view containing only Puppis A among known sources has led to the discovery of a new OSO-8 source, OSO752-39. Other spectra from this region are discussed
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ExoMars entry, descent and landing science
The entry, descent and landing of ExoMars offer a rare (once-per-mission) opportunity to perform in situ investigation of the martian environment over a wide altitude range. Entry, Descent and Landing System (EDLS) measurements can provide essential data for atmospheric scientific investigations.
We intend to perform atmospheric science measurements by exploiting data from EDLS engineering sensors and exploiting their readings beyond the expected engineering information
CP Studies of the Higgs Sector
The CP structure of the Higgs sector will be of great interest to future
colliders. The measurement of the CP properties of candidate Higgs particles
will be essential in order to distinguish models of electroweak symmetry
breaking, and to discover or place limits on CP-violation in the Higgs sector.
In this report we briefly summarize various methods of determining the CP
properties of Higgs bosons at different colliders and identify areas where more
study is required. We also provide an example of a synergy between the LHC, an
e+e- Linear Collider and a Photon Collider, for the examination of CP-violation
in a Two-Higgs-Doublet-Model.Comment: A contribution to the LHC / LC Study Group document; 9 pages, 2
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Detection of structure in asteroid analogue materials and Titan’s regolith by a landing spacecraft
We compare measurements made by two impact penetrometers of different sizes and with different tip shapes to further understand penetrometer design for performing pentrometry on an asteroid. To this end we re-visit the interpretation of data from the Huygens' penetrometer, ACC-E, that impacted Titan's surface. In addition we investigate the potential of a spacecraft fitted with a penetrometer to bounce using a test rig, built at The Open University (UK).
Analysis of ACC-E laboratory data, obtained from impacts into ~4 mm diameter gravel, was found to produce an unusual decrease in resistance with depth (force-depth gradient) which was also seen in the Huygens' ACCE data from Titan and originally interpreted as a wet or moist sand. The downward trend could also be reproduced in a hybrid Discrete Element Model (DEM) if it was assumed that the near surface particles are more readily mobilised than those deeper in the target.
With regard to penetrometer design penetration resistance was found to be sensitive to the ratio of particle to tip diameter. A clear trend was observed with a conical tip penetrometer, X-PEN, of decreasing force-depth gradients with increasing particle sizes most likely due to a transformation from a bulk displacement of material by the penetrating tip to more local interactions. ACC-E, which has a hemispherical tip, was found to produce a wider range of force-depth gradients than X-PEN, which had a conical tip, possibly due to difficulties dislodging jammed particles. Both penetrometers were able to determine particle diameter and mass after post-processing of the data.
Laboratory simulations of landings with the test rig suggest that a large impact penetrometer under certain circumstances could absorb a significant amount of the elastic energy of the spacecraft possibly aiding landing. Alternatively a small impact penetrometer would allow the spacecraft to bounce freely on the surface to make a measurement at another location
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Exomars entry and descent science
The entry, descent and landing of ExoMars offer a rare (once-per-mission) opportunity to perform in situ investigation of the martian environment over a wide altitude range. We present an initial assessment of the atmospheric science that can be performed using sensors of the Entry, Descent and Landing System (EDLS), over and above the expected engineering information. This is intended to help fulfill the concept of an Atmospheric Parameters Package (APP), as mentioned in the ExoMars draft Science Management Plan [ESA, 2005].
Mars' atmosphere is highly variable in time and space, due to phenomena including inertio-gravity waves, thermal tide effects, dust, solar wind conditions, and diurnal, seasonal and topographic effects. Atmospheric profile measurements, drawing on heritage from the Huygens Atmospheric Structure Instrument (HASI), which encountered Titan's atmosphere
in 2005 [1], should allow us to address questions of the martian atmosphere's structure, dynamics and variability
Physics at Future Linear Colliders
This article summarises the physics at future linear colliders. It will be
shown that in all studied physics scenarios a 1 TeV linear collider in addition
to the LHC will enhance our knowledge significantly and helps to reconstruct
the model of new physics nature has chosen.Comment: Invited talk at the Lepton Photon Symposium 2005, Upsala, Sweden,
July 2005, V2: minor improvement
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