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The Hubble Space Telescope captures grayscale images of galaxies, which are enhanced with color using filters. It was named after astronomer Edwin Hubble and had a blurry start, but was fixed by spacewalking astronauts. Its successor, the James Webb Space Telescope, will launch in 2021.
You may have seen some out-of-this-world photographs of galaxies far, far away taken by the Hubble Space Telescope (HST), which was launched into space by Space Shuttle Discovery in 1990. But before the public sees those breathtaking images of nebulae and supernovae, digital images consisting of only grayscale pixels are enhanced with color, created through multiple-exposure overlays that combine images using various filters, typically red, blue, and green. These filters capture only specific wavelengths of light, which are then used to create a color composite image.
We can clearly see now:
The deep-space telescope is named after astronomer Edwin Hubble, who determined in 1924 that Andromeda was a galaxy millions of light-years away from Earth, not a nebula.
The first images from HST returned to Earth out of focus, due to a tiny ‘spherical aberration’ in its main focusing mirror. In 1993, spacewalking astronauts added a tool to correct his blurry vision.
HST’s successor, called the James Webb Space Telescope, will launch in 2021. The $10 billion satellite will be positioned well beyond the Moon, more than 1 million miles (1.6 million km) from Earth.
