As NASA’s Hubble telescope made its millionth observation on Monday, scientists were delighted by its ability to capture stunning images of the cosmos.

For 21 years Hubble has been the premier space science observatory, astounding us with deeply beautiful imagery and enabling ground-breaking science across a wide spectrum of astronomical disciplines, said NASA Administrator Charles Bolden.

Hubble, which turned 21 recently, was launched on April 24, 1990, aboard space shuttle's Discovery's STS-31 mission. Its discoveries in the last 21 years have revolutionized nearly all areas of astronomical research from planetary science to cosmology. It has captured nebulae of different shapes and ashtonished scientists with galaxies' images thousands of light years away.

Hubble images show the most spectacular views of the ever expanding universe.

According to NASA, the observatory has collected more than 50 terabytes of data.

The Hubble keeps amazing us with groundbreaking science, said Sen. Barbara A. Mikulski, the chairperson of the Senate Commerce, Justice, Science and Related Agencies Appropriations Subcommittee that funds NASA.

Hubble is a project of international cooperation between NASA and the European Space Agency.

Start the slideshow to view the most beautiful astronomical images captured by Hubble all these years.

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