(S (S (NP (NP (BASENP (DT The) (NNS details)) (PP (IN of) (BASENP (DT the) (NN discovery)))) (PRN (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VP (VBD took) (BASENP (NN place))) (PP (IN on) (BASENP (NNP December) (NN 19) (JJ last) (NN year)))))) (COMMA ,))) (VP (VBZ has) (VP (ADVP (RB only)) (VP (ADVP (RB just)) (VP (VBN been) (VP (VBN made) (ADVP (RB public)))))))) (PERIOD .))