Pillars of Creation

The "Pillars of Creation" from the Eagle Nebula.

"Pillars of Creation" is a photograph taken by the Hubble Telescope of elephant trunks of interstellar gas and dust in the Eagle Nebula, some 7,000 light years from Earth.^[1] They are so named because the gas and dust are in the process of forming, or creating, new stars, while also being eroded by the light from nearby stars that have recently formed.^[2] Taken April 1, 1995, it was named one of the top ten photographs from the Hubble by Space.com.^[3] The astronomers responsible for the photo were Jeff Hester and Paul Scowen, at the time both of Arizona State University. In 2011, the region was revisited by ESA's Herschel Space Observatory.

Composition

The pillars are composed of cool molecular hydrogen and dust that are being eroded away by photoevaporation from the ultraviolet light of relatively close and hot stars. The leftmost pillar is about four light years in length.^[4] The finger-like protrusions at the top of the clouds are larger than our solar system, and are made visible by the shadows of Evaporating Gaseous Globules (EGGs), which shields the gas behind them from intense UV flux.^[5] EGGs are themselves incubators of new stars.^[6]

Destruction

Images of taken with the Spitzer Space Telescope uncovered a cloud of hot dust in the vicinity of the Pillars of Creation that one group interpreted to be a shock wave produced by a supernova. The appearance of the cloud suggests a supernova that would have been seen on Earth as exploding somewhere between 1000 and 2000 years ago, and will hit and destroy the pillars in another 1000 years. Given the distance of roughly 6000 light years to the Pillars of Creation, this would mean that they have actually already been destroyed, but because of the finite speed of light, this destruction is not yet visible on Earth, but should be visible in the next 1000 years.^[7] However, this interpretation of the hot dust has been disputed by an astronomer uninvolved in the Spitzer observations, who argues that a supernova should have resulted in stronger radio and x-ray radiation than has been observed, and that winds from massive stars could instead have heated the dust. If this is the case, the Pillars of Creation will undergo a more gradual erosion.^[8]

Hubble's photo

Hubble's photo of the pillars is composed of 32 different images^[9] from four separate cameras^[10] in the Wide Field and Planetary Camera 2 on board Hubble.^[11] The photograph was made with light emitted by different elements in the cloud and appears as a different colour in the composite image: green for hydrogen, red for singly ionized sulphur and blue for double-ionized oxygen atoms.^[2]

The missing part of the picture at the top right corner originates from the fact that one of the four cameras has a magnified view of its portion, which allows astronomers to see finer detail. Thus the images from this camera are scaled down in size proportionally to match the other three cameras.^[10]

Herschel's photo

In 2011 Herschel Space Observatory captured a new image of Pillars of Creation in far-infrared wavelengths, which allows astronomers to look inside the pillars and structures in the region, and come to a much fuller understanding of the creative and destructive forces inside the Eagle nebula.^[12]

References

External links

Media related to Pillars of Creation at Wikimedia Commons