Pictured: The galactic wreck that predicts our future… in five billion years

Astronomers have created a ‘galactic train wreck’ atlas image depicting how a variety of galaxies around Earth will collide in five billion years time.
The collision between the Milky Way – Earth’s galaxy – and the Andromeda Galaxy is predicted to take place in between three and five billion years.
The ‘train wreck’ style merger of galaxies, is said by experts to reveal ‘how galaxies form, grow and evolve’.
The atlas of galaxy collision was created using data from NASA’s Spitzer and Galex space telescopes.

Galactic 'smash-up': A montage shows three galaxy collisions in the newly-released 'train wreck' atlas

The Galex (Galaxy Evolution Explorer) telescope observes in ultraviolet light, which captures emission from hot young stars.
Spitzer sees the infrared emission from warm dust heated by those stars, as well as from stellar surfaces.
Some galaxies, such as the NGC 935 and the IC 1801, have already begun their galactic ‘smash-up’.
But the collision between Earth’s Milky Way and the Andromeda Galaxy is not expected to take place for several billion years.
The collision is likely to trigger the birth of stars from smashed together clouds of cosmic gas and dust.
Lauranne Lanz of the Harvard Smithsonian Center for Astrophysics, said: ‘This atlas is the first step in reading the story of how galaxies form, grow, and evolve.

Captured: The telescope atlas also depicted the NGC 935 and the IC 1801 galaxy collision

‘We’re working with the theorists to give our understanding a reality check.
‘Our understanding will really be tested in five billion years when the Milky Way experiences its own collision.’
The combined data highlight areas where stars are forming most rapidly, and together permit a more complete census of the new stars.
In general, galaxy collisions trigger star formation, though some mergers trigger few stars than others.
Lanz and her colleagues want to figure out what differences in physical processes cause these varying outcomes, which will help guide computer simulations of these smashups.

Collision: Infrared emission dust from the M51 galaxy and ultraviolet emission was captured using the telescopes


Spitzer Sees Crystal Rain in Infant Star Outer Clouds

Cosmic Fountain of Crystal Rain
NASA’s Spitzer Space Telescope detected tiny green crystals, called olivine, thought to be raining down on a developing star. This graphic illustrates the process, beginning with a picture of the star and ending with an artist’s concept of what the crystal “rain” might look like. The top picture was taken in infrared light by NASA’s Spitzer Space Telescope. An arrow points to the embryonic star, called HOPS-68. The middle panel illustrates how the olivine crystals are suspected to have been transported into the outer cloud around the developing star, or protostar. Jets shooting away from the protostar, where temperatures are hot enough to cook the crystals, are thought to have transported them to the outer cloud, where temperatures are much colder. Astronomers say the crystals are raining back down onto the swirling disk of planet-forming dust circling the star, as depicted in the final panel.

Stars Adorn Orion’s Sword
This image from NASA’s Spitzer Space Telescope shows what lies near the sword of the constellation Orion — an active stellar nursery containing thousands of young stars and developing protostars. Many will turn out like our sun. Some are even more massive. These massive stars light up the Orion nebula, which is seen here as the bright region near the center of the image.
To the north of the Orion nebula is a dark filamentary cloud of cold dust and gas, over 5 light-years in length, containing ruby red protostars that jewel the hilt of Orion’s sword. These are the newest generation of stars in this stellar nursery, and include the protostar HOPS 68, where Spitzer spotted tiny green crystals in a surrounding cloud of gas.

Finding Forsterite Around a Developing Star
Using NASA’s Spitzer Space Telescope, astronomers have, for the first time, found signatures of silicate crystals around a newly forming protostar in the constellation of Orion. The crystals are from the olivine silicate minerals known as forsterite, and are similar to those found on the green sand beaches of Hawaii.
The data in the graph were taken by Spitzer’s infrared spectrograph, which sorts infrared light relative to its color, or wavelength. The characteristic spectral signatures of the crystals are shaded in green. The formation of forsterite crystals requires relatively high temperatures near 1,300 degrees Fahrenheit (700 degrees Celsius). The crystals were not expected to beseen in the cold environment of a newly forming star (minus 280 degrees Fahrenheit or minus 130 degrees Celsius). Astronomers believe that these crystals were created near the protostar and carried up to a cold, collapsing cloud of gas and dust by jets of gas. The crystals are expected to eventually rain back down onto the protostar’s planet-forming disk, possibly to be used in the formation of comets.

Read more: http://www.nasa.gov/mission_pages/spitzer/news/spitzer20110526.html