Dartmouth Events

Abstract: 

The NASA Magnetospheric Multiscale (MMS) mission was launched on March 12, 2015 to begin a quest for better understanding of magnetic reconnection.  In order to investigate the three-dimensional nature and the ion and electron physics of magnetic reconnection, MMS has four spacecraft deployed in a tetrahedral configuration with spacings adjustable from 400 km down to 10 km, 3D plasma measurements (<30 keV) with unprecedented time resolution (30 ms and 150 ms for electrons and ions, respectively), 3D magnetic (~0.1 nT) and electric (<0.5 mV/m) fields with 1 ms time resolution and waves (<6 kHz for electric and magnetic, and up to 100 kHz for electric only), 3D energetic particles with composition up to 500 keV, and plasma ion composition (< 30 keV/q).

After completion of payload commissioning on September 1, 2015, MMS will begin its science mission with a low-latitude scan of the dayside magnetopause during which the spacecraft separations will be adjusted between 10 km and 160 km. A second scan of the dayside magnetopause will be performed with a fixed spacecraft separation as determined from the first scan. After the second scan the apogee of the elliptical orbits will be raised from 12 Earth radii to 25 Earth radii for a traversal of the nightside magnetic tail region with spacecraft separations between 10 km and 400 km. Reconnection occurs near continuously on the day side where there typically is a significant guide field and in the tail where densities are lower and the magnetic field orientation is typically anti-parallel.

I will discuss the present state of the MMS mission, its capabilities to address outstanding questions on reconnection, and a few preliminary events that MMS has observed.