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► DARTS of the Month

THEMIS Data Mirror Site Open

The THEMIS (Time History of Events and Macroscale Interactions During Substorms) mission, as its name indicates, primarily aims to elucidate the triggering mechanism of magnetospheric substorms which closely relate to auroral breakup. The mission consists of five magnetospheric spacecraft, launched in the USA in February 2007, as well as magnetometers and auroral all-sky imagers, installed at ground-based observatories in Canada and Alaska.

A mirror site of the THEMIS spacecraft and ground data was opened at DARTS this summer. The spacecraft and geomagnetic field data are fully mirrored, while only summary data are mirrored for the auroral imager data.

Furthermore, the Geotail spacecraft is still being operated by ISAS and continues to observe the Earth's magnetosphere. For promoting conjunction studies using both of THEMIS and Geotail data, we publish plots of definitive and predictive orbits and quick-look data as well as Conjunction Event Finder at DARTS to browse the data efficiently.

Yukinaga Miyashita (ISAS/JAXA)

September 2008