File:Hubblecast 54.webm

English: To celebrate the 22nd anniversary of the NASA/ESA Hubble Space Telescope this month, episode 54 of the Hubblecast gives a slideshow of some of the best images from over two decades in orbit, set to specially commissioned music.

Please note that although this episode does not have narration, the images are described in subtitles which can be displayed by clicking on the “CC” (closed captioning) button.

List of images and descriptions:

1990: Saturn Among the first images to be sent back from Hubble after its launch in April 1990, this image of Saturn is good by the standards of ground-based telescopes, but slightly blurry. This is because of the well-publicised problem with Hubble’s mirror, which did not allow images to be focused properly.

1991: Orion Nebula Although not perfectly sharp, this early image of the Orion Nebula nevertheless shows the rich colours and structures of this bright star-forming region.

1992: Herbig-Haro 2 Throughout the region of the Orion Nebula are numerous streamers of gas that come from newborn stars, known to astronomers as Herbig-Haro Objects.

1993: Messier 100 In late 1993, Hubble’s teething problems were resolved in the first servicing mission. Before-and-after images of the core of spiral galaxy Messier 100 show how this dramatically improved the telescope’s image quality.

1994: Shoemaker-Levy 9 hits Jupiter Soon after the astronauts repaired Hubble during the first servicing mission, comet Shoemaker-Levy 9 collided with Jupiter. A similar impact on Earth 65 million years ago is thought to have killed off the dinosaurs.

1995: Eagle Nebula Hubble’s image of the ‘pillars of creation’ in the Eagle Nebula is one of its most famous. These huge, dusty structures enshroud pockets of ongoing star formation.

1996: NGC 6826 This image from 1996 shows a planetary nebula, which represents the other extremity of a star’s life from the Eagle Nebula. Planetary nebulae form when Sun-like stars puff out their outer layers as they run low on fuel. They are so named because of their roughly spherical shape and green colour, not because of the presence of any planets.

1997: Mars NASA’s Mars Pathfinder probe was en route to Mars in 1997 while Hubble took this image. Although Hubble cannot compete with the resolution of images taken from probes which actually fly past or land on planets, it does offer the advantage of being able to make long-term observations, useful for studying planets’ climates and weather.

1998: Ring Nebula Another planetary nebula, the Ring Nebula is one of the most famous.

1999: Keyhole Nebula The Keyhole Nebula, part of the larger Carina Nebula is another bright star-forming region.

2000: NGC 1999 Not all nebulae glow brightly. NGC 1999 contains a dark patch silhouetted against a brighter background which reflects starlight.

2001: ESO 510-G13 Hubble’s image of this galaxy shows the dramatic deformations that can occur after collisions between galaxies. Although the immense distance between stars makes it vanishingly unlikely for stars to actually collide with each other, the tidal forces can warp and tear galaxies out of shape.

2002: Cone Nebula Further upgrades in 2002, including the installation of the Advanced Camera for Surveys increased resolution and picture quality again. Hubble’s ultra-sharp image of the Cone Nebula demonstrates the new instrument’s capabilities.

2003: Hubble Ultra Deep Field Usually astronomers know what they’re going to look at when they plan their observations. For the Hubble Ultra Deep Field, observed over 11 days between September 2003 and January 2004, they did not. Pointing the telescope at an extremely dark patch of sky devoid of nearby stars, this extremely long exposure was designed to see the most distant and faintest galaxies in the Universe.

2004: Antennae Galaxies The dramatic collision of two spiral galaxies is visible in this image of the Antennae Galaxies. The bright pink patches visible across much of the vista are pockets of star formation triggered by the gravitational interaction of the galaxies.

2005: The Orion Nebula This image of the Orion Nebula is one of the largest and most detailed ever made.

2006: Messier 9 Globular clusters, roughly spherical collections of stars, contain some of the oldest stars in our Milky Way. Hubble’s high resolution observations allow astronomers to discern individual stars right into the centre of these clusters.

2007: NGC 4874 This image of NGC 4874, a galaxy in the Coma Cluster, was taken with the Advanced Camera for Surveys just two days before it suffered an electronic failure in January 2007. For the next two years, astronomers would have to make do with lower resolution images from Hubble’s other cameras.

2008: NGC 2818 This image of planetary nebula NGC 2818 dates from this period. It is worth noting that even with its capabilities constrained, Hubble was still able to produce images that compete with any telescope on the ground.

2009: Bug Nebula In 2009, astronauts travelled to Hubble for another servicing mission, which installed new and upgraded cameras. The Bug Nebula was one of the first images sent back: Hubble was back in business.

2010: Centaurus A Using its new instrumentation, Hubble peered into the heart of Centaurus A, a dramatically dusty galaxy.

2011: Tarantula Nebula Just published in April 2012, this image of the Tarantula Nebula combines a mosaic of Hubble observations, which capture the detail and structure of the nebula, with observations of glowing hydrogen and oxygen from the European Southern Observatory’s MPG/ESO 2.2-metre telescope in Chile, which provide colour. The image is one of the most detailed ever made of a star-forming region, weighing in at an astonishing 330 megapixels.

2012: ??? Most of Hubble’s data are only made public a year after they are made, in order to give the team who designed the observations some time to study and publish their results. And it sometimes takes a few more years before the pictures get processed and released to the public. So what’s Hubble’s best picture from 2012? You’ll just have to wait to find out...

Credit:ESA/Hubble