Researchers have finally managed to measure the expansion rate of the universe with great precision, and it's all thanks to Hubble.

Teams from NASA and the University of Baltimore (United States) were able to use the catalog of images collected over thirty-two years by the space telescope.

The researchers are pleased to have been able to give "the most precise measurement of the expansion rate of the universe from the ultimate in telescopes and space markers", explains Adam Riess, Nobel Prize in 2011, on the site of the US space agency.

The importance of the "Hubble constant"

Scientists agree that our universe has been expanding since the Big Bang, explains

Le Journal du Geek


The different objects that make up the Universe are moving away from each other.

All astrophysical models are based on this.

It is important to know the expansion rate of the universe.

But on this point, the opinions of scientists diverged, without always understanding why.

They did not arrive at the same result to establish “the constant of Hubble”, of the name of the astronomer who discovered the phenomenon of the expansion.

This is why this latest work with the Hubble telescope is important.

To obtain this Hubble constant, the scientists took as their tools the 42 supernovae that Hubble has captured since its commissioning.

Supernovae are characterized by violent explosions which remain visible for a long time, given the energy released.

To refine the rate of expansion of the Universe, the researchers plotted the relative positions of all these objects over time.

A sure result

As a result, the Hubble constant would be equivalent to 73 km/s/Mpc, showing that the size of the Universe will double within 10 billion years.

Previously, scientists agreed on the rate of 67.15 km/s/Mpc measured by the European Space Agency.

This new measurement is precise and reliable because the possibility of an error has been estimated at less than one risk in a million.

Hubble will therefore have valiantly ensured one of its missions.

"That's the kind of thing it was built for," commented Adam Riess.

The telescope will be gradually replaced by the James-Webb telescope, launched in December 2021 and currently in the test phase.


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  • Universe

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  • Hubble

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