The model was expanded 7,630 kilometers (4,740 mi) in 2012 to include Alpha Centauri, the star system closest to the Sun. The Alpha Centauri Obelisk is exhibited at the ʻImiloa Astronomy Center at the University of Hawaii in Hilo, Hawaii. The volcanic stone Hawaiian figure representing Alpha Centauri in female form has a 280 millimetres (11 in) semicircle under its chin to represent its scale size. This extension made the Sagan Planet Walk the world's largest exhibition.