On April 24, 1990, the Hubble Space Telescope was launched into orbit. It has transformed what we know about outer space, from our own solar system to the edges of the universe.

It has shown us some of the first galaxies ever formed and helped us learn the age of the universe.

Hubble is able to take awesome images because it orbits above the Earth’s atmosphere. The atmosphere can blur images taken from Earth and block the light from space.

Hubble’s origins

In 1925, astronomer Edwin Hubble observed that most galaxies appear to be moving away from all the other galaxies. This is because the universe is stretching out, or expanding.

Astronomers discovered, with Hubble and other telescopes, that this expansion is actually speeding up. The entire universe is expanding faster now than in the past.

No one knows what is pushing the universe out like this. Scientists call the mysterious force dark energy.

Knowing how fast the universe is expanding helps astronomers figure out its age. Information from Hubble and other telescopes offers strong evidence that the universe formed about 13.8 billion years ago.

Hubble was developed by the U.S. space program and the European Space Agency. It orbits our planet 320 miles above the surface and travels at about 17,000 mph. Over the years, 32 astronauts have flown to Hubble to service the telescope.

Hubble’s accomplishments

Since its launch in 1990, Hubble has made more than 1.6 million observations about more than 100 million astronomical objects. It sends about 150 gigabits of scientific data to Earth every week.

The telescope is able to do this because it gathers wavelengths of light from the ultraviolet through the near-infrared part of the electromagnetic spectrum. With 35 years of images, scientists can study objects in space that are changing over time.

For example, Hubble has proven that supermassive black holes are at the cores of most galaxies. It was the first to gather images of the surface of a star other than our sun.

* A nebula is a cloud of dust and gas in space.

Our solar system

When Hubble launched, there were not yet any confirmed planets outside our solar system. Since then, scientists have found more than 5,000 exoplanets, or planets outside our solar system.

Hubble has also captured images of comet fragments and asteroids slamming into Jupiter and leaving huge scars on the planet.

Our galaxy

Hubble has made many discoveries in our own Milky Way galaxy. For example, it has detected flattened disks of stardust orbiting newborn stars. It found evidence that planets form in these dusty disks.

Having confirmed the existence of many exoplanets, it is analyzing their atmospheres and has detected water vapor and other substances within some of them. These findings help scientists explore the possibilities of life on other planets.

Our universe

Some of Hubble’s images show the oldest galaxies soon after they were born, when they were still taking shape. They look like links in a chain or like toothpicks. The closer galaxies have had more time to form the familiar spiral shapes.

Mini Fact:

In 2017, Hubble captured SBW1, a nebula* with a giant star that is predicted to explode.