5 iconic images from NASA that changed our view of the universe

Ever since we broke the bonds of gravity and ventured outside Earth's atmosphere, we have been traveling on a journey with many stops but no destination. After centuries of exploration, we are yet to know all there is about the universe. However, we do know some. NASA's spacecraft, astronauts and investigation of space have taught humans a lot about what exists outside the planet. These are 5 iconic images from NASA that changed our view of the universe.

The "Earthrise" photograph was taken by astronaut Bill Anders as Apollo 8 completed its final pass around the far side of the Moon in 1968. It was the first time humans saw how Earth looked over the limb of the moon. After seeing the photographs, Sister Mary Jacunda wrote to NASA to stop wasting money on exploring space when there was so much suffering on Earth. In a reply, Ernst Stuhlinger, the Associate Director of Science at NASA back then wrote a letter to Jacunda, attaching the photo of the Earthrise. "Ever since this picture was first published, voices have become a louder and louder warning of the grave problems that confront man in our times: pollution, hunger, poverty, urban living, food production, water control, overpopulation," he wrote.

The Pale Blue Dot is an image of Earth taken from the furthest distance ever. The image was captured in 1990 by the Voyager 1 spacecraft when it was returning to the planet. It made everyone on Earth realise the fragility of the planet and humans when compared to the galaxy. "There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world" said Carl Sagan who requested to capture the image which was not a part of the plan.

Taken in 1995, the Hubble Deep Field image was taken over the course of 23 days by pointing at a blank patch of sky and collecting single photons every day. It was these photographs that revealed to us what lay away in the black sky- over 5,000 distant galaxies. Over the years even more galaxies have been captured, two trillion.

Humans have been taught that stars are formed from gases, but we got the first proof of it in 1995 when Hubble discovered columns of gas amid stars in the Eagle Nebula. These columns had proto-stars, stars that were still in the process of formation. However, these forming stars are also responsible for the evaporation of the nebulae due to the hot ultraviolet light being emitted from them. The nebulae in space are responsible for the creation of stars that are formed when cool molecular gas contracts under gravity.

The first-ever image of a black hole was taken in 2019 by a network of global telescopes called the Event Horizon Telescope (EHT). It depicted a supermassive black hole in the centre of the Messier 87 (M87) galaxy. While scientists had theorised the black hole, the images provided direct visual evidence for the first time ever.