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Life after death in the
Crab Nebula

...a team of scientists has detected polarized gamma-ray emission from the vicinity of the Crab Nebula, providing insight into the processes that bring a dead star to life...

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Getting closer to the Milky Way’s black hole

...astronomers have stared deep into the heart of the supermassive black hole that is thought to lurk at the centre of our own Milky Way Galaxy...

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Comets disguised as asteroids

...between five and ten percent of Near Earth Objects could be comets impersonating asteroids...

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Video archive

STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.


STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.


STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

 Full presentation
 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.


Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

 Full coverage

Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

 Launch | Science

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Observations of a Milky Way look-alike

Posted: September 04, 2008

ESO's Wide Field Imager (WFI), attached to the 2.2 metre Max-Planck Society/ESO telescope in Chile, has captured the intricate swirls of the barred spiral galaxy Messier 83, a smaller version of our own Milky Way.

Colour-composite image of M83, as seen by ESO's Wide Field Imager (WFI), attached to the 2.2-metre Max-Planck Society/ESO telescope in Chile. The brighter stars in the foreground are stars in our own Galaxy, whilst behind M83 the darkness is peppered with the faint smudges of distant galaxies. Image: ESO.

M83, often nicknamed the Southern Pinwheel because of its spectacular spiral arms, lies roughly 15 million light-years away towards the huge southern constellation of Hydra, and spans a distance of over 40,000 light-years, making it roughly 2.5 times smaller than our own Milky Way. Despite the difference in size however, M83 shares some familiar traits with the Milky Way; both possess a bar across their galactic nucleus, and a dense pool of stars packed into their centres.

The new image was composed by training the WFI on the galaxy for around 100 minutes, which brought out the exquisite details in the galaxy’s arms and the ruby red glow of hydrogen gas marking the sites of newly born massive stars. These stellar newborns are bathed in thick ultraviolet radiation which ionises the galaxy’s gas clouds, producing the red glow. These star forming regions are contrasted dramatically against the ethereal glow of older yellow stars towards the galaxy's central hub, and the delicate dust streams waving throughout the arms.

Other recent observations of M83 in ultraviolet light and radio waves have shown that even the far reaches of the galaxy – further than revealed in this image – are populated with baby stars, while X-ray observations of the heart of M83 reveal an oven of frenetic star formation within a cloud of gas superheated to seven million degrees Celsius.

Messier 83 is also one of the most prolific producers of supernovae and is one of two galaxies which has witnessed six supernovae in the past 100 years. One of these, SN 1957D was observable for 30 years.