  Within 40 years of the detection of the first extrasolar X-ray source in
1962,NASA's Chandra X-ray Observatory has achieved an increase in sensitivity
of 10 orders of magnitude, comparable to the gain in going from naked-eye
observations to the most powerful optical telescopes over the past 400 years.
Chandra is unique in its capabilities for producing sub-arcsecond X-ray images
with 100-200 eV energy resolution for energies in the range 0.08<E<10 keV,
locating X-ray sources to high precision, detecting extremely faint sources,
and obtaining high resolution spectra of selected cosmic phenomena. The
extended Chandra mission provides a long observing baseline with stable and
well-calibrated instruments, enabling temporal studies over time-scales from
milliseconds to years. In this report we present a selection of highlights that
illustrate how observations using Chandra, sometimes alone, but often in
conjunction with other telescopes, have deepened, and in some instances
revolutionized, our understanding of topics as diverse as protoplanetary
nebulae; massive stars; supernova explosions; pulsar wind nebulae; the
superfluid interior of neutron stars; accretion flows around black holes; the
growth of supermassive black holes and their role in the regulation of star
formation and growth of galaxies; impacts of collisions, mergers, and feedback
on growth and evolution of groups and clusters of galaxies; and properties of
dark matter and dark energy.
