Time and space, as never seen before
Hubble scientists produce mosaic showing more than a quarter of a million galaxies. Andrew Masterson reports.
Astronomers have combined images from 16 years of observations made by Hubble Space Telescope, operated jointly by NASA and the European Space Agency, to create a mosaic that is, in every possible way, huge.
Called the Hubble Legacy Field, it depicts approximately 265,000 galaxies. Not stars, galaxies.
Given the time that light takes to travel, some of the galaxies depicted stretch back to just 500 million years after the Big Bang. The faintest and farthest of them are just one ten-billionth the brightness of what the human eye can observe.
To create the mosaic, Hubble images covering wavelengths from ultraviolet to near-infrared light were incorporated.
“Now that we have gone wider than in previous surveys, we are harvesting many more distant galaxies in the largest such dataset ever produced,” says Garth Illingworth of the University of California, Santa Cruz, in the US, who led the team that assembled the image.
“No image will surpass this one until future space telescopes like James Webb are launched."
The mosaic incorporates 7500 individual pictures, produced by 31 separate Hubble projects. The team is now working on a second image, incorporating 5200 more images.
The original pictures are available through the Mikulski Archive for Space Telescopes (MAST).