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  • 1. Carlsson, Ella
    Finding Mars on Svalbard: a study of Martian gullies on Earth2008In: Polarforskningssekretariatet: årsbok 2008, Stockholm: Swedish Polar Research Secretariat , 2008, 34-35 p.Chapter in book (Other (popular science, discussion, etc.))
  • 2. Carlsson, Ella
    Finns det liv på Mars?2007In: Nya Upplagan, no 10, 10- p.Article in journal (Other (popular science, discussion, etc.))
  • 3.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Framåt Mars !2006Book (Other (popular science, discussion, etc.))
  • 4.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mars: environment, surface and exploration ethics2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This licentiate thesis treats the solar wind interaction with the martian atmosphere and the water related features known as gullies, as well as some ethical issues related to the human exploration of Mars. The composition of the escaping plasma at Mars has been investigated in an analysis of data from the IMA sensor, which is part of the ASPERA-3 instrument suit onboard the European satellite Mars Express. The cause for the investigation is to determine if there are any large abundances of escaping ion species incorporating carbon, such as in CO_2^+. The most abundant ion species was found to be O^+ and O_2^+, followed by CO_2^+. The following ratios were identified: (CO_2^+)/(O^+)=0.2 and (O_2^+)/(O^+)=0.9. The loss of CO_2^+ was estimated to 4.0x10^(24) s^(-1) (0.29 kg/s). The escaping plasma in form of ion beam events has also been correlated to the magnetic anomalies found on the surface, where no clear association was found. This study is important in order to understand the evolution of Mars, since some evidence reveals that ancient Mars was once a wetter planet. The gully formations have been investigated with data from the MOC and MOLA instruments onboard the satellite Mars Global Surveyor. The intriguing features suggest that there has been fluvial erosion on the surface of Mars. The shallow and deep aquifer models remain the most plausible formation theories. Gully formation is another important piece to the puzzle regarding the lost water on Mars. Since Mars once harbored stable water on the surface in the past, astrobiologists believe that life could have existed on Mars. Some even argue for a slight possibility to find life thriving in the subsurface today, where the water can be found in a stable liquid form. If this would be the case we need to consider whether we should continue with our in-situ exploration of the surface, or if we should leave Mars to the Martians.

  • 5. Carlsson, Ella
    Mars Express and Venus Express multi-point observations of geoeffective solar flare events in December 20062008In: Planetary and Space Science, ISSN 0032-0633, E-ISSN 1873-5088, Vol. 56, 873-880 p.Article in journal (Refereed)
    Abstract [en]

    In December 2006, a single active region produced a series of proton solar flares, with X-ray class up to the X9.0 level, starting on 5December 2006 at 10:35 UT. A feature of this X9.0 flare is that associated MeV particles were observed at Venus and Mars by VenusExpress (VEX) and Mars Express (MEX), which were 801 and 1251 east of the flare site, respectively, in addition to the Earth, whichwas 791 west of the flare site. On December 5, 2006, the plasma instruments ASPERA-3 and ASPERA-4 on board MEX and VEXdetected a large enhancement in their respective background count levels. This is a typical signature of solar energetic particle (SEP)events, i.e., intensive MeV particle fluxes. The timings of these enhancements were consistent with the estimated field-aligned travel timeof particles associated with the X9.0 flare that followed the Parker spiral to reach Venus and Mars. Coronal mass ejection (CME)

  • 6. Carlsson, Ella
    Mars finns redan på jorden2004In: Populär astronomi, ISSN 1650-7177, Vol. 5, no 2, 30-33 p.Article in journal (Other (popular science, discussion, etc.))
  • 7. Carlsson, Ella
    Mars: plasma environment and surface2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis treats parts of the solar wind interaction with the Martian atmosphere and the water-related features known as gullies. The composition of the escaping plasma at Mars has been investigated in an analysis of data from the IMA sensor, which is a part of the ASPERA-3 instrument suit onboard the European satellite Mars Express. The goal of the investigation is to determine if there are any high abundances of escaping ion species incorporating carbon, such as in CO_2^+ . The most abundant ion species was found to be O^+ and O_2^+, followed by CO_2^+. The following ratios were identifed: CO_2^+/O^+ = 0:2 and O_2^+ /O^+ = 0:9. The escaping plasma, in form of ion beam events, has also been correlated to the magnetic anomalies found on the surface, where no clear association was found. Similar ion beams have also been detected on Venus, which does not have any crustal magnetic fields, and hence the fields are not required for the formation process of the beams. The ion beams' dependence of the direction of the solar wind convection electric field has also been studied, where a correlation was found, suggesting that the ion beams are accelerated by this field. The studies mentioned above are important in order to understand the evolution of Mars and its atmosphere, as well as plasma acceleration processes at non-magnetized planetary bodies. On 5 December 2006 the ASPERA instruments of both Venus Express and Mars Express detected a large enhancement in their respective background count level. These readings are associated with events of SEPs (Solar Energetic Particles), which are believed to be coupled with the CMEs (Coronal Mass Ejection) identified 43 ¡ 67 hours after the SEPs. The CMEs occurred on the far side of the sun (with respect to the locations of Venus and Mars), which indicates that these events can a®ect the space weather in areas situated 90 degrees in both azimuthal directions in the heliosphere with respect to the target. During this event the heavy ion outflow from the atmosphere of Mars increased by one order of magnitude, suggesting that EUV flux levels significantly affect the atmospheric loss from unmagnetized bodies. The gully formations have been investigated with data from the MOC, MOLA and TES instruments onboard the satellite Mars Global Surveyor. The features suggest that there has been fluvial erosion on the surface of Mars. The shallow and deep aquifer models remain the most plausible formation theories. Gully formation processes are important to understand since their eroding agent may be liquid water.

  • 8.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Martian rights?2005In: International Space Review, ISSN 1746-1588, no 3, 5-6 p.Article in journal (Other academic)
  • 9. Carlsson, Ella
    Mot rymden för att rädda jorden!2007In: Texter om kosmos: en antologi, Lidingö: Adoxa , 2007, 231-245 p.Chapter in book (Other (popular science, discussion, etc.))
  • 10.
    Carlsson, Ella
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Cold Mars2006Conference paper (Other academic)
  • 11. Carlsson, Ella
    et al.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Fedorov, A.
    Centre d’Etude Spatiale des Rayonnements, Toulouse.
    Budnik, E.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Grigoriev, Alexander
    Futaana, Y.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Gunell, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Nilsson, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Lundin, R.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Analysis of the mass composition of the escaping plasma at Mars2006In: 2006 European Geosciences Union General Assembly (EGU 2006), Austria Center Vienna, Vienna (Austria), 2-7 Apr 2006, European Geosciences Union (EGU), 2006Conference paper (Other academic)
    Abstract [en]

    Results from Mars Express, Mars Exploration Rovers and Mars Global Surveyor indicate that Mars harbored large amounts of liquid water on the surface in the past. In order for the water-associated geomorphologic features to form, the pressure in the atmosphere must have been at least a hundred times higher to produce the necessary greenhouse effect required to hold liquid water stable. The present atmospheric pressure is only 6-9 mbar and moreover, the spectral imaging of Mars suggests that the amount of carbonates stored in the surface is too low in order to explain the denser atmosphere in the past. This controversy led us to investigate the escaping plasma by analyzing the data from the IMA sensor (Ion Mass Analyzer) of the ASPERA-3 instrument suite onboard Mars Express. The IMA sensor measures the differential flow of ion components in the energy range of 0.01-30 keV/q.Since the instrument design was optimized for studies of plasma dynamics, the mass resolution is not adequate enough to directly resolve CO+2 from O+2 , which is the main molecular ion composing the Mars ionosphere according to theoretical models. Therefore, a special multi-species fitting technique, using calibration and in-flight data, was developed to resolve the CO+2 peak from the neighboring and much more intense O+2 peak. This technique was applied to the observations covering the period from April 4, 2004 to October 2, 2005. The events of heavy ion escape were identified inside the induced magnetosphere boundary and the Martian eclipse. We report the results of statistical studies of these ion-beam events which permitted to determine CO+2 / O+ and the O+2 / O+ ratio of the escaping plasma at Mars.

  • 12. Carlsson, Ella
    et al.
    Brain, D.
    Space Science Laboratory, University of California, Berkeley.
    Luhmann, J.
    Space Science Laboratory, University of California, Berkeley.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Grigoriev, Alexander
    Nilsson, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Lundin, R.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Influence of IMF draping direction and crustal magnetic field location on Martian ion beams2008In: Planetary and Space Science, ISSN 0032-0633, E-ISSN 1873-5088, Vol. 56, no 6, 861-867 p.Article in journal (Refereed)
    Abstract [en]

    Data from the Ion Mass Analyzer (IMA) sensor of the ASPERA-3 instrument suite onboard Mars Express and data from the Magnetometer/Electron Reflectometer (MAG/ER) on Mars Global Surveyor have been analyzed to determine whether ion beam events (IBEs) are correlated with the direction of the draped interplanetary magnetic field (IMF) or the proximity of strong crustal magnetic fields to the subsolar point. We examined 150 IBEs and found that they are organized by IMF draping direction. However, no clear dependence on the subsolar longitude of the strongest magnetic anomaly is evident, making it uncertain whether crustal magnetic fields have an effect on the formation of the beams. We also examined data from the IMA sensor of the ASPERA-4 instrument suite on Venus Express and found that IBEs are observed at Venus as well, which indicates the morphology of the Martian and Venusian magnetotails are similar.

  • 13. Carlsson, Ella
    et al.
    Euler, M. von
    Lunds universitet.
    Grigoriev, Alexander
    McCann, David
    Habitat for Mars: a new conceptual design2007In: Geophysical Research Abstracts, European Geosciences Union (EGU), 2007, Vol. 9Conference paper (Other academic)
  • 14.
    Carlsson, Ella
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Fedorov, A.
    Centre d’Etude Spatiale des Rayonnements, Toulouse.
    Barabash, S.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Dierker, C.
    Technical University of Braunschweig.
    Mass composition of the escaping plasma at Mars2006In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 182, no 2, 320-328 p.Article in journal (Refereed)
    Abstract [en]

    Data from the Ion Mass Analyzer (IMA) sensor of the ASPERA-3 instrument suite on Mars Express have been analyzed to determine the mass composition of the escaping ion species at Mars. We have examined 77 different ion-beam events and we present the results in terms of flux ratios between the following ion species: CO2+/O+ and O-2(+)/O+. The following ratios averaged over all events and energies were identified: CO2+/O+ = 0.2 and O-2(+)/O+ = 0.9. The values measured are significantly higher, by a factor of 10 for O-2(+)/O+, than a contemporary modeled ratio for the maximum fluxes which the martian ionosphere can supply. The most abundant ion species was found to be O+, followed by O-2(+) and CO2+. We estimate the loss of CO2+ to be 4.0 x 10(24) s(-1) (0.29 kg s(-1)) by using the previous measurements of Phobos-2 in our calculations. The dependence of the ion ratios in relation to their energy ranges we studied, 0.3-3.0 keV, indicated that no clear correlation was found.

  • 15. Carlsson, Ella
    et al.
    Fedorov, A.
    Budnik, E.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Fredriksson, Sverker
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    First results from ASPERA-3 Ion Mass Analyzer (IMA) on CO2+ escape2005Conference paper (Other academic)
  • 16.
    Gunell, H.
    et al.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Nilsson, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Amerstorfer, U.V.
    Space Research Institute, Austrian Academy of Sciences.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Indications of plasma instabilities near Mars2006Conference paper (Other academic)
    Abstract [en]

    It has been suggested in the literature that the Kelvin-Helmholtz instability can be responsible for significant ion loss at Mars through the detachment of ionospheric plasma clouds. Clouds of detached ionospheric plasma were observed at Venus by the Pioneer Venus orbiter. The conditions at Mars differ somewhat from those at Venus. The ratio between the ion gyro radius and the radius of the planet is larger at Mars than at Venus, since Mars is a smaller planet and the solar wind magnetic field is weaker at Mars than at Venus. It is therefore interesting to study instabilities at Mars and to compare the results from Mars with those from Venus. We search the ASPERA-3 data for signatures of instabilities at Mars, in particular looking at the magnetosheath and the induced magnetosphere boundary.

  • 17.
    Gunell, Herbert
    et al.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Nilsson, H.
    Amerstorfer, U.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grima, C.
    Plasma instabilities near Mars2006In: Ikke angivet, Committee on Space Research , 2006, 2338- p.Conference paper (Other academic)
    Abstract [en]

    It has been suggested in the literature that the Kelvin-Helmholtz instability can be responsible for significant ion loss at Mars through the detachment of ionospheric plasma clouds Clouds of detached ionospheric plasma were observed at Venus by the Pioneer Venus orbiter The conditions at Mars differ somewhat from those at Venus The ratio between the ion gyro radius and the radius of the planet is larger at Mars than at Venus since Mars is a smaller planet and the solar wind magnetic field is weaker at Mars than at Venus It is therefore interesting to study instabilities at Mars and to compare the results from Mars with those from Venus We search the ion and electron data from the ASPERA-3 instrument on the Mars Express spacecraft for signatures of instabilities at Mars We present data indicative of instabilities in the magnetosheath and the induced magnetosphere boundary downstream of the planet

  • 18. Heldmann, J. L.
    et al.
    Johansson, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mellon, M.T.
    Northern hemisphere gullies on Mars: analysis of spacecraft data and implications for formation mechanisms2005In: 36th Annual Lunar and Planetary Science Conference: papers presented at the Thirty-sixth Lunar and Planetary Science Conference : March 14-18, 2005 / [ed] Stephen J. Mackwell, Houston, Tex: Lunar and planetary institute , 2005Conference paper (Other academic)
  • 19.
    Heldmann, Jennifer L.
    et al.
    NASA Ames Research Center.
    Carlsson, Ella
    Johansson, Henrik
    Luleå tekniska universitet.
    Mellon, Michael T.
    University of Colorado.
    Toon, Owen B.
    University of Colorado.
    Observations of martian gullies and constraints on potential formation mechanisms: Part 2. The northern hemisphere2007In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 188, no 2, 324-344 p.Article in journal (Refereed)
    Abstract [en]

    The formation process(es) responsible for creating the observed geologically recent gully features on Mars has remained the subject of intense debate since their discovery. We present new data and analysis of northern hemisphere gullies from Mars Global Surveyor data which is used to test the various proposed mechanisms of gully formation. We located 137 Mars Orbiter Camera (MOC) images in the northern hemisphere that contain clear evidence of gully landforms and analyzed these images in combination with Mars Orbiter Laser Altimeter (MOLA) and Thermal Emission Spectrometer (TES) data to provide quantitative measurements of numerous gully characteristics. Parameters we measured include apparent source depth and distribution, vertical and horizontal dimensions, slopes, orientations, and present-day characteristics that affect local ground temperatures. Northern hemisphere gullies are clustered in Arcadia Planitia, Tempe Terra, Acidalia Planitia, and Utopia Planitia. These gullies form in craters (84%), knobby terrain (4%), valleys (3%), other/unknown terrains (9%) and are found on all slope orientations although the majority of gullies are equator-facing. Most gullies (63%) are associated with competent rock strata, 26% are not associated with strata, and 11% are ambiguous. Assuming thermal conductivities derived from TES measurements as well as modeled surface temperatures, we find that 95% of the gully alcove bases with adequate data coverage lie at depths where subsurface temperatures are greater than 273 K and 5% of the alcove bases lie within the solid water regime. The average alcove length is 470 m and the average channel length is 690 m. Based on a comparison of measured gully features with predictions from the various models of gully formation, we find that models involving carbon dioxide, melting ground ice in the upper few meters of the soil, dry landslide, and surface snowmelt are the least likely to describe the formation of the martian gullies. Although some discrepancies still exist between prediction and observation, the shallow and deep aquifer models remain as the most plausible theories. Interior processes involving subsurface fluid sources are generally favored over exogenic processes such as wind and snowfall for explaining the origin of the martian gullies. These findings gleaned from the northern hemisphere data are in general agreement with analyses of gullies in the southern hemisphere [Heldmann, J.L., Mellon, M.T., 2004. Icarus 168, 285-304].

  • 20.
    Nilsson, H.
    et al.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Carlsson, Ella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Gunell, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Futaana, Y.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Lundin, R.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Fedorov, A.
    Centre d’Etude Spatiale des Rayonnements, Toulouse.
    Soobiah, Y.
    Mullard Space Science Laboratory, Imperial College.
    Coates, A.
    Mullard Space Science Laboratory, Imperial College.
    Fränz, M.
    MPI für Sonnensystemforschung, Katlenberg-Lindau.
    Roussos, E.
    MPI für Sonnensystemforschung, Katlenberg-Lindau.
    Investigation of the influence of magnetic anomalies on ion distributions at Mars2006In: Space Science Reviews, ISSN 0038-6308, E-ISSN 1572-9672, Vol. 126, no 1-4, 355-372 p.Article in journal (Refereed)
    Abstract [en]

    Using data from the Mars Express Ion Mass Analyzer (IMA) we investigate the distribution of ion beams of planetary origin and search for an influence from Mars crustal magnetic anomalies. We have concentrated on ion beams observed inside the induced magnetosphere boundary (magnetic pile-up boundary). Some north-south asymmetry is seen in the data, but no longitudinal structure resembling that of the crustal anomalies. Comparing the occurrence rate of ion beams with magnetic field strength at 400 km altitude below the spacecraft (using statistical Mars Global Surveyor results) shows a decrease of the occurrence rate for modest (< 40 nT) magnetic fields. Higher magnetic field regions (above 40 nT at 400 km) are sampled so seldom that the statistics are poor but the data is consistent with some ion outflow events being closely associated with the stronger anomalies. This ion flow does not significantly affect the overall distribution of ion beams around Mars.

  • 21.
    Nilsson, H.
    et al.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Fedorov, A.
    CESR, Toulouse.
    Lundin, R.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Carlsson, Ella
    Gunell, H.
    Swedish Institute of Space Physics / Institutet för rymdfysik.
    Barabash, Stas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Coates, A.
    MSSL, London.
    Fränz, M.
    MPI, Katlenburg-Lindau.
    A survey of heavy ion beam events observed by Mars Express and the possible influence of magnetic anomalies2006Conference paper (Other academic)
    Abstract [en]

    We extend previous studies of heavy ion beams observed in the vicinity of Mars by the Mars Express ASPERA-3 ion mass analyzer. The spatial properties, i.e. location and direction of flow are investigated. It is discussed whether any of the spatial characteristics indicate an influence of magnetic anomalies. The ion events concern heated/accelerated ions with energies above 300 eV so the gyro radii of the ions are mostly large compared to the size of magnetic anomalies. Therefore phenomena such as bending of the ion path or heating up to some threshold energy after which the ions are lost from the anomaly due to gyro radii effects are the kind of effects we are looking for.

1 - 21 of 21
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