1993/07/16 by M. G. Kivelson, L. F. Bargatze, K. K. Khurana +3 · 5 citations
Physics and Astronomy · Biochemistry, Genetics and Molecular Biology · #Astro and Planetary Science #Geomagnetism and Paleomagnetism Studies #Solar and Space Plasma Dynamics #Physics #Magnetic field #Solar wind #Asteroid #Galileo (satellite navigation) #Geophysics #Field (mathematics) #Astrophysics #Computational physics #Geodesy #Geology #Astronomy
paper · doi:10.1126/science.261.5119.331
openalex publication_date 1993/07/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Two large magnetic field rotations were recorded by the spacecraft Galileo 1 minute before and 2 minutes after its closest approach to the asteroid Gaspra. The timing and the geometry of the field changes suggest a connection with Gaspra, and the events can be interpreted as the result of the draping of the solar wind field around a magnetospheric obstacle. Gaspra's surface field is inferred to be within an order of magnitude of Earth's surface field, and its magnetic moment per unit mass is in the range observed for iron meteorites and highly magnetized chondrites. The location of the magnetic signatures suggests that perturbations are carried by waves in the magnetosonic-whistler mode with wavelengths between electron and ion gyro radii.