Happy birthday Hubble!

Twenty years ago, on 24. April 1990, the Hubble Space Telescope was launched into orbit. Since then, Hubble has given us many spectacular images, allowing us to explore and understand a little bit more the Universe.
Let us review some of the most relevant Hubble telescopes's science finding:

• Dark energy: the term "dark energy" refers to a force against the gravity; it is then responsible of the expansion of the Universe. By observing distant supernovae, the astronomers can study how the dark energy behaves, which is a key to understand the origin of the Universe.
• The age of the Universe: by measuring the brightness of pulsating stars it was possible to calculate their distance to the Earth. This parameter was used to determine the Hubble constant and the Universe's age, estimated to be around 13,75 billion years.
• Large galaxies: Hubble has registered images of galaxies when the universe was just 100 million years; these observations revealed that they were smaller than today's galaxies, concluding that large galaxies built up over time as smaller galaxies collided and merged.
• Extrasolar planets: planets out of our Solar System are called extrasolar planets. Hubble has detected many of them and made significant contributions to broaden our knowledge about them. For instance, its observations showed for the first time in history the composition of the atmosphere of one extrasolar planet.

+Info:
This post has been adapted from "Hubble space telescope's top science findings".
A complete review of select research papers can be found in this special issue of Nature.
More information about Hubble telescope and stunning images from it, can be found in the official website:

HUBBLE SITE