RocketSTEM Issue #11 - April 2015 | Page 98

Reflection 51. Nebula in Orion Just weeks after NASA astronauts repaired the Hubble Space Telescope in December 1999, the Hubble Heritage Project snapped this picture of NGC 1999, a nebula in the constellation Orion. The Heritage astronomers, in collaboration with scientists in Texas and Ireland, used Hubble’s Wide Field Planetary Camera 2 (WFPC2) to obtain this colour image. Credit: NASA/ESA and the Hubble Heritage Team (STScI) Jupiter impact 52.comet zones from This true colour image of the giant planet Jupiter, by NASA and ESA’s Hubble Space Telescope, reveals the impact sites of fragments ‘D’ and ‘G’ from Comet Shoemaker-Levy 9. Credit: H. Hammel, MIT and NASA/ESA Bright 53. quasar 3C 273 This image is likely the best of ancient and brilliant quasar 3C 273, which resides in a giant elliptical galaxy in the constellation of Virgo (The Virgin). Its light has taken some 2.5 billion years to reach us. Despite this great distance, it is still one of the closest quasars to our home. It was the first quasar ever to be identified, and was discovered in the early 1960s by astronomer Allan Sandage. The term quasar is an abbreviation of the phrase “quasi-stellar radio source”, as they appear to be star-like on the sky. In fact, quasars are the intensely powerful centres of distant, active galaxies, powered by a huge disc of particles surrounding a supermassive black hole. As material from this disc falls inwards, some quasars — including 3C 273 — have been observed to fire off super-fast jets into the surrounding space. In this picture, one of these jets appears as a cloudy streak, measuring some 200 000 light-years in length. Credit: ESA/Hubble & NASA