53 Kalypso
Kalypso ( minor planet designation: 53 Kalypso ) is a large and very dark main belt asteroid that was discovered by German astronomer Robert Luther on April 4 , 1858 , at Düsseldorf . 
<triplet> 53 Kalypso <subj> main belt <obj> minor planet group <subj> asteroid <obj> instance of <subj> Robert Luther <obj> discoverer or inventor