A5094096295- Astro and Planetary Science
- Planetary Science and Exploration
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
- Solar and Space Plasma Dynamics
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Methane Hydrates and Related Phenomena
Space Research Institute
2024-2025
Austrian Academy of Sciences
2024-2025
Between 1974 and 1975, the Mariner 10 spacecraft investigated Mercury's environment during three flybys. By using its ultraviolet spectrometer, it identified helium, atomic oxygen, hydrogen atoms in Mercury’s exosphere. Interestingly, no H2 molecules were detected these Based on data from occultation instrument, an upper limit for surface density was established detection threshold of about 1.4 x 107 cm-3. Here, we present first in-situ Hermean Exosphere, through magnetic field...
One can separate the atmospheric evolution of Venus into two epochs. The first epoch lasts from final accreted planet 4.5 Gyr ago to "last" resurfacing that occurred about 200-1000 Myr ago. second this event until today. Venus’ atmosphere during beginning was exposed by very high solar EUV flux values, probably, water produced interaction between a primordial and magma ocean, incorporated planet’s accretion carbonaceous chondrites or mixture both sources. different...
Abstract Since its detection by Mariner 10, helium has been a key focus in studies of Mercury's exosphere. Recently, Weichbold et al. (2025), https://doi.org/10.1029/2024je008679 provided the first situ measurements, inferring density from Ion Cyclotron Wave (ICW) events observed MESSENGER spacecraft. This approach enables, for time, profile across broad altitude range without relying on prior models. We present an ab‐initio model steady state, solar wind‐driven exosphere, which informed...
Abstract Helium (He) was first detected by remote spectroscopic observations of the Ultraviolet Visible Spectrometers (UVVS) instrument in Mercury's exosphere during three Mariner 10 flybys 1974 and 1975. Here, we derive situ radial density profile He extended analyzing magnetic field plasma measurements from 2011 to 2015 obtained MErcury Surface, Space ENvironment, Geophysics, Ranging (MESSENGER) spacecraft. Our results indicate that most exospheric follows a thermal trend. Interestingly,...
In this study, we suggest a model for the origin and abundance of exospheric Helium at Mercury. It was derived ab initio, assuming He-saturated regolith surface “steady-state” exosphere. A 1D Monte Carlo computer simulation [1] used to calculate He density profiles according model. The in Hermean exosphere first constrained from UV Spectrometer measurements aboard Mariner 10 [2] has been discussed extensively since, also light probable analogies Lunar environment. is...
Mariner 10 detected the existence of an exosphere around Mercury in 1974-1975 by remote spectrometric observations during flybys. More than four decades later MErcury Surface, Space ENvironment, Geochemistry and Ranging (MESSENGER) spacecraft confirmed exosphere. So far, neutral helium (He) number density Mercury’s was based on assumptions related to spectroscopic observations, which are applied exospheric models derive altitude-dependent profile planet. Here, we present first...
Mercury has an extended exosphere that consists of various species. Based on theoretical considerations, the existence Lithium (Li) in around is predicted to be less than 5x107 cm-2. Because these density values are well below detection limits remote observation instruments board past missions, Li never been directly observed. Here we show first on-site determined altitude-density profile atomic Li7, derived from in-situ magnetic field observations by MESSENGER spacecraft. The results...