  A Chandra observation of the radio-loud quasar 3C9 at redshift z=2.012 has
revealed extended X-ray emission coincident with the radio jet. Of particular
interest is the appearance of both jet and counterjet, which argues against the
X-ray emission being highly beamed. We present the properties of the jets and
discuss possible scenarios for the X-ray emission, contrasting them with the
single sided jet found in PKS 0637-752, which has a similar X-ray luminosity.
The jet X-ray emission in 3C9 is likely to be due to either nonthermal emission
from a sheath with bulk Lorentz factor less than 1.5, or thermal emission from
shocked cold gas surrounding the quasar. The thermal possibility implies a high
mass for the cold gas unless it is highly clumped.
