The low gravity of #Mars & lack of magnetic field makes its outermost atmosphere an easy target to be swept away by solar wind, but @esa’s Mars Express shows that the Sun’s radiation may play a surprising role in its escape ☀️💨 ➡️ https://t.co/2esJJ6iHs3 pic.twitter.com/wa40nqBhS4

— ESA Science (@esascience) February 8, 2018