About a century ago, we didn’t even know that galaxies existed.
Mai Lam/The Conversation NY-BD-CC
Pretty much as soon as we understood what galaxies were, we realised they are all moving away from each other. And the ones that are further away are moving faster. In short, the universe is expanding.
UK's Astronomer Royal Martin Rees shares his memories of the physicist Stephen Hawking, who has died at the age of 76.
An artist’s rendering of how the first stars in the universe may have looked.
N.R. Fuller, National Science Foundation
Signals from the first stars to form in the universe have been picked up by a table-sized detector in a west Australian desert. The find also hints at an early interaction with dark matter.
Timeline of the universe.
From blindingly bright and burning hot to pleasantly 'candle-lit', the first years of the universe would have been spectacular to see.
Andy Rain/ EPA
Hawking proved that the Big Bang was physically possible.
Part of the new map of dark matter made from gravitational lensing measurements of 26 million galaxies in the Dark Energy Survey.
Chihway Chang/University of Chicago/DES collaboration
We still can't see the dark matter thought to make up about a quarter of the universe, but at least now we have a map of its structure.
Mine’s a Star-opramen.
It's like one great big distillery up there.
In the beginning, the Universe expanded very, very fast.
What caused the Big Bang is still a mystery. And that's just one of the many unanswered questions, in spite of everything we do know about the birth of the Universe.
Some of the earliest known galaxies in the universe, seen by the Hubble Space Telescope.
Atoms blown up in the right way could signal when a gravitational wave is passing through.
The truth is we don’t really know if space goes on forever – but maybe, one day, we will find out.
People used to think that when they looked up at the night sky, they were seeing all of space. Then American astronomer Edwin Hubble found out something so amazing, NASA named a telescope after him.
Light from the universe’s first galaxies destroyed the hydrogen atoms that formed during the Big Bang.
NASA, ESA, R. Ellis (Caltech), and the UDF 2012 Team
A new telescope aims to figure out what became of the universe's original atoms once the first stars began to shine.
In part two of our podcast on rebooting, we explore what would happen if humanity was wiped out, take a look at a political comeback in France, and get a taste of a revamped US institution.
An artist’s impression of the galaxies found in the ‘Zone of Avoidance’ behind our Milky Way.
International Centre for Radio Astronomy Research
Something mysterious is pulling our Milky Way through space at a much faster rate than expected. So what could it be?
Why the night sky can tell us a fair bit about time.
Arches National Park/Flickr
It's all relative – why scientists understand time in a completely different way.
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Why gravitational waves from the birth of the universe are a whole different story than the waves LIGO detected.
Space: it’s full of stars … isn’t it?
If there are infinite stars – where is all the light?
A colour image of G63349, one of the galaxies in the survey, created using near-infrared (VISTA telescope) and optical (Sloan telescope) data collated by the GAMA survey. (The bright green object is a nearby star.)
Our universe's most exciting days are well behind us, with new research showing the universe is now slowly but surely dying.
This month marks the 50th anniversary of the discovery of the Cosmic Microwave Background, which is the radiation left over from the birth of the universe.
The epoch of the leptons existed for nine seconds after the Big Bang.
Big Bang by Shutterstock
Subatomic particles have shaped and continue to shape our universe but despite perfect predictions by physicists, the theory about unseen particles is still wrong.
Something new discovered near our Milky Way.
Several dwarf galaxies have been discovered close to our own Milky Way and are adding to our understanding of how galaxies form. But why haven't astronomers seen them before?