IUCN Red List, Tarantula Nebula

The IUCN Red List categorizes animal and plant species by risk of extinction. It uses specific criteria to organize species into one of seven main categories: Least Concern (LC), Near Threatened (NT), Vulnerable (VU), Endangered (EN), Critically Endangered (CR), Extinct in the Wild (EW), and Extinct (EX). A species is officially considered "threatened" when it falls under VU, EN, or CR. A species may also be labeled as Possibly Extinct (EX?CR) or Possibly Extinct in the Wild (EW?CR). As of 2007, amphibians are clearly the most threatened group, followed by mammals and birds. Insects, quite unsurprisingly, represent the least concerned group.



The Tarantula Nebula (30 Doradus or NGC 2070), located in the Large Magellanic Cloud, is the only extragalactic nebula observable with the unaided eye. Given this, 30 Doradus is an incredibly bright nebula, one of the brightest emission nebula discovered. The Tarantula Nebula acquires its brightness the same way as the Orion Nebula (i.e. by UV radiation from hot stars), but the former is about a hundred times larger. To put this in scale, if it replaced the Orion Nebula, it would cast shadows upon the earth. Its intense luminosity is a consequence of the formation of large concentrations of Wolf-Rayet stars in its starburst region. It has regions of ionized gases, including ions of iron, neon, sulfur and argon. SN 1987A occurred in the Tarantula Nebula.