Revisiting the Strongest Martian X-Ray Halo Observed by XMM-Newton on 2003 November 19-21 On 2003 November 20-21, when the most intense geomagnetic storm during solar cycle 23 was observed at Earth, XMM-Newton recorded the strongest Martian X-ra... L Yan,J Gao,RY Wei - 《Astrophysical ...