The photograph taken by the Hubble space telescope that marked a before and after in astronomical research
In 1990 the Hubble Space Telescope began its journey. With some other problem involved, finally began to reveal the sharpest images of the Universe, without an atmosphere in between that made it difficult for us to see the stars. Five years later, in 1995, he took what is probably his most important photograph: Hubble Deep Field. A look at millions of years of history of the Universe.
If you look at the most popular images from HubbleThey are usually colorful nebulae or stars. Hubble Deep Field is more humble, dozens of background galaxies that barely look like tiny dots. Likewise, it was done in a totally different way than how Hubble took photographs until then. To finish in style, the use that was given to the captured data was also different.
Pointing to nothing
Generally, when astronomers sought to photograph with a telescope, the process consisted of pointing towards the star of interest and then taking the photograph. For the Hubble Deep Field image, the team of researchers in charge of Hubble had a different idea: aim at nothing, and see what you find.
So the team led by Robert Williams decided to find un point in the Universe where to point the telescope and where no observations have been made before. In an effort to see how far Hubble could see and, above all, to study the evolution of galaxies.
The goal was to see farther from our own galaxy, so the observation point had to be far from the plane of the Milky Way. They also needed to keep it away from other groups of stars or galaxies, as long as there was no light pollution. Finally, they needed to find a point that could be observed from the entire orbit of Hubble, since the telescope was circling the Earth and it could cover the target. They found a point near and above the constellation Ursa Major.
On December 18, 1995, Hubble began its observations from “nowhere”. During the next ten days the telescope took 342 photographs of the point in question.
The evolution of the Universe
Once the photographs were processed, the Hubble team was able to have a final image, the Hubble Deep Field. An image in which you can see some stars that were in the way but where the protagonists are the galaxies. Of different sizes, colors and shapes the galaxies “appeared out of nowhere” and allowed us to see one of the most interesting images we have of the Universe.
Why is this photograph special? Because shows us the historical evolution of the Universe and its galaxies. Since light takes billions of years to reach us from so far away, it allows us to see snapshots of what the Universe was like then. The smallest and barely dotted galaxies correspond to the early stages of galaxies, while the larger, spiral-shaped galaxies are more recent. It is as if we were photographing a street in Rome and seeing current cars, Romans from 2,000 years ago and wild animals from 50,000 years ago.
Two years later, Hubble did this test again at another point in the Universe, this time in the Southern Hemisphere. Hubble Deep Field South revealed similar results, with galaxies of different sizes and shapes proved that the first of the photographs was no exceptionbut the norm.
Finally, what makes this photograph interesting is what the research team decided to do with it: make it public. Instead of keeping the collected data for themselves and studying it in private, they decided to make the research public and the data was accessible to any scientific team. Something that today is relatively normal, on NASA’s own website there are thousands of unprocessed files available for analysis, but not at that time.
Via | National Geographic