- John Walter Gregory (Wikipedia)
John Walter Gregory, FRS, FRSE, FGS (27 January 1864 – 2 June 1932) was a British geologist and explorer, known principally for his work on glacial geology and on the geography and geology of Australia and East Africa.
- Ring Nebula (Wikipedia)
The Ring Nebula (also catalogued as Messier 57, M57 and NGC 6720) is a planetary nebula in the northern constellation of Lyra. Such a nebula is formed when a star, during the last stages of its evolution before becoming a white dwarf, expels a vast luminous envelope of ionized gas into the surrounding interstellar space.