The Plasma Environment of Comet 67P/Churyumov-Gerasimenko.

The environment of a comet is a fascinating and unique laboratory to study plasma processes and the formation of structures such as shocks and discontinuities from electron scales to ion scales and above. The European Space Agency's Rosetta mission collected data for more than two years, from the rendezvous with comet 67P/Churyumov-Gerasimenko in August 2014 until the final touch-down of the spacecraft end of September 2016. This escort phase spanned a large arc of the comet's orbit around the Sun, including its perihelion and corresponding to heliocentric distances between 3.

A Fast Bow Shock Location Predictor-Estimator From 2D and 3D Analytical Models: Application to Mars and the MAVEN Mission.

We present fast algorithms to automatically estimate the statistical position of the bow shock from spacecraft data, using existing analytical two-dimensional (2D) and three-dimensional (3D) models of the shock surface. We derive expressions of the standoff distances in 2D and 3D and of the normal to the bow shock at any given point on it. Two simple bow shock detection algorithms are constructed, one solely based on a geometrical predictor from existing models, the other using this predicted position to further refine it with the help of magnetometer data, an instrument flown on many planetary missions.

Percutaneous alcohol embolization and vertebroplasty of a T2 aggressive vertebral hemangioma with prior embolization of dangerous arterial anastomoses.

Aggressive vertebral hemangiomas usually exhibit extraosseous expansion that can result in spinal cord or radicular compression.1 In symptomatic cases, treatment by alcohol embolization and percutaneous vertebroplasty has been reported as feasible, safe, and effective with long-term benefits on neurological symptoms.2 Safety rules before vertebral alcohol embolization include preoperative spinal cord vascularization mapping and opacification through bone needles to assess the absence of dangerous intratumoral anastomoses.