The field of orbital mechanics began long ago when Johannes Kepler discovered that planets moved in regular, elliptical paths and Isaac Newton discovered that gravity is universal.
(The field of orbital mechanics; began; T:long ago; T:when Johannes Kepler discovered that planets moved in regular, elliptical paths and Isaac Newton discovered that gravity is universal) (Johannes Kepler; discovered; that planets moved in regular, elliptical paths and Isaac Newton discovered that gravity is universal) Context(Johannes Kepler discovered,List([51, 77))):(planets; moved; in regular, elliptical paths) (Isaac Newton; discovered; that gravity is universal) Context(Isaac Newton discovered,List([130, 153))):(gravity; is; universal)
Johannes Kepler discovered,List([51, 77)) Isaac Newton discovered,List([130, 153))
The field of orbital mechanics Johannes Kepler planets Isaac Newton gravity
began discovered moved discovered is
T:long ago T:when Johannes Kepler discovered that planets moved in regular, elliptical paths and Isaac Newton discovered that gravity is universal
that planets moved in regular, elliptical paths and Isaac Newton discovered that gravity is universal
in regular, elliptical paths
that gravity is universal
universal