2 April The inoperative Tiangong-1 space lab comes down over the South Pacific Ocean, northwest of Tahiti.[105][106] Astronomers report the detection of the most distant individual star (actually, a blue supergiant), named Icarus (formally, MACS J1149 Lensed Star 1), at 9 billion light-years (light-travel distance) away from Earth.[107][108] 5 April – Odilorhabdins, a novel class of naturally-produced antibiotics, is formally described.[109] 10 April – Researchers in Japan report finding centuries' worth of rare-earth metals in deep sea mud, located near Minami-Tori-shima in the northwest Pacific.[110][111][112] 11 April – Two studies, both published in Nature,[113][114] find that the warm Atlantic Gulf Stream is at its weakest for at least 1,600 years.[115] 17 April – Engineers at MIT develop a new more efficient method of producing long strips of graphene.[116][117] 18 April NASA's Transiting Exoplanet Survey Satellite (TESS) is launched.[118][119] Nanyang Technological University demonstrates a robot that can autonomously assemble an IKEA chair without interruption.[120][121]