This composite X-ray (blue)/optical (orange) image of M86 shows gas being swept
out of the galaxy to form a long tail more than 200,000 light years in length. M86 has been
pulled into the Virgo galaxy cluster and accelerated to a speed of about 3 million miles per
hour by the enormous combined gravity of dark matter, hot gas, and hundreds of galaxies
that comprise the cluster. The supersonic motion of the galaxy through the diffuse hot gas
produces pressure that is stripping gas from M86 and forming the spectacular tail.