This Hubble Space Telescope image shows thousands of sparkling young stars nestled within the giant nebula NGC 3603. This stellar "jewel box" is one of the most massive young star clusters in our Milky Way Galaxy. NGC 3603 is a prominent star-forming region in the Carina spiral arm of the Milky Way, about 20,000 light-years from Earth. This image shows a young star cluster surrounded by a vast region of dust and gas. The nebula was first discovered by Sir John Herschel in 1834. This image spans an area roughly 17 light-years across.