NASA’s Hubble Telescope delivered its milestone millionth science observation of 21 years on July 4, exposing the chemical composition of the planet HAT-P-7b, also known as Kepler 2b.

Often described as a gas giant planet larger than Jupiter orbiting a star hotter than our sun, Kepler 2b was discovered by NASA's planet-hunting Kepler spacecraft’s observatory in 2008.

The Hubble Space Telescope recorded its millionth observation while it was on a mission to search for water in the atmosphere of the extra solar planet, which is about 1,000 light-years away, NASA said in a statement on Tuesday.

Kepler 2b is a hot Jupiter class planet orbiting a star that is much hotter than our sun. Hubble Space Telescope's millionth science observation was trained on this planet to look for the presence of water vapor and to study the planet's atmospheric structure via spectroscopy, it added.

Check out pictures of Hubble’s iconic millionth observation that will allow astronomers to do follow-up observations of exoplanets (a planet outside our solar system) to characterize the composition and structure of their atmospheres:

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