The crew then discovered the Ross Ice Shelf, which they were unable to penetrate, and followed it eastward until the lateness of the season compelled them to return to Van Diemen's Land. The following season, 1842, Ross continued to survey the "Great Ice Barrier", as it was called, continuing to follow it eastward. Both ships returned to the Falkland Islands before returning to the Antarctic in the 1842–1843 season. They conducted studies in magnetism, and returned with oceanographic data and collections of botanical and ornithological specimens. The plants were described in the resulting "The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror in the years 1839–1843, under the Command of Captain Sir James Clark Ross".