The many small-body exploration missions that have occurred over the last few decades shown small solar system objects are covered with granular material of varying depth. These also observed materials mobilized from surfaces at speeds on order escape speed by different contributing mechanisms. Those result in various outcomes including and reimpact. latter contributes to further impact-driven ...

This study is carried out in the framework of sample-return missions to asteroids that use a low-speed projectile as the primary component of its sampling mechanism (e.g., JAXA’s Hayabusa and Hayabusa2 missions). We perform numerical simulations of such impacts into granular materials using different projectile shapes under Earth's gravity. We then compare the amounts of ejected mass obtained i...

[1] The discovery of terrestrial-scale extrasolar planets, and their calculated abundance in the galaxy, has prompted speculation on their surface conditions and thermal structure. Both are dependent on the tectonic regime of a planet, which is itself a function of the balance between driving forces, and the resistive strength of the lithosphere. Here we use mantle convection simulations to sho...

the dedicated satellite mission goce will sense various small mass variations along its path around the earth. here we study the effect of the earth’s topography and atmosphere on goce data. the effects depend on the magnitude of topographic height, and they will therefore vary by region. as the effect of the atmosphere and topography must be removed from the total gravity anomaly prior to geoi...

The precise tracking of distance variations between two satellites in low Earth orbit can provide key data for the understanding Earth’s system, specifically on seasonal and sub-seasonal water cycles their impact levels. Measured variations, caused by local gravitational field, serve as inputs to complex gravity models with which movement globe be identified. Satellite missions GOCE (2009–2013)...

the three-phase-lag model and green–naghdi theory without energy dissipation are employed to study the deformation of a two-temperature fiber-reinforced medium with an internal heat source that is moving with a constant speed under a hydrostatic initial stress and the gravity field.  the modulus of the elasticity is given as a linear function of the reference temperature. the exact expressions ...

GOCE will be the first satellite gravity mission measuring gravity gradients in space using a dedicated instrument called a gradiometer. High resolution gravity field recovery will be possible from these gradients. Such a recovery requires a proper description of the gravity gradient errors, where the a priori error model is for example based on end-to-end instrument simulations. One way to tes...

Missions finalized at measuring the space-time variations of Earth gravity field have become high relevance in recent years. These missions are indeed interest for scientific purposes and applications several fields. Precise observations can be accomplished by distance between two satellites flying suitable orbits. Several mission concepts foresee an active formation control to maintain within ...

Abstract Satellite missions providing data for a continuous monitoring of the Earth gravity field and its changes are fundamental to study climate changes, hydrology, sea level solid phenomena. GRACE-FO (Gravity Recovery Climate Experiment Follow-On) mission was launched in 2018 NGGM (Next Generation Gravity Mission) studies ongoing long-term time-variable field. In recent years, an innovative ...