Complex sentence: PSR B1257 +12B was the first planet ever discovered outside the Solar system, and is the second object known to be orbiting the pulsar PSR B1257 +12, which it circles at a distance of 0.36 AU with an orbital period of approximately 66 days.
Split into simpler sentences: PSR B1257 +12B was the first planet ever discovered outside the Solar system, and is the second object known to be orbiting the pulsar PSR B1257 +12. At a distance of 0.36 AU with an orbital period of approximately 66 days.