Back in October last year, there was a very exciting announcement that researchers had photographed two colliding neutron stars for the first time.

During all the hullabaloo, Stephen Hawking did an interview with Pallab Ghosh, a science correspondent at BBC News, who got his thoughts on the detection of gravitational waves, black holes, and how to produce gold.

It's now known to be his last broadcast interview before he died earlier this month, and yesterday the BBC published the full interview.

If you don't know what happened with the colliding neutron stars, here's what our senior writer Michelle Starr reported at the time:

"For the first time ever, scientists around the world have managed to photograph a collision between two neutron stars, 130 million light-years away.

"And it's all thanks to gravitational wave astronomy, which identified the event and alerted observatories on where to look."

Even more incredible, this was only the fifth gravitational wave ever discovered.

Hawking's BBC interview about the discovery definitely left us in awe of the cosmos.

Speaking to Ghosh, Hawking said that the detection of these colliding neutron stars "is a genuine milestone".

"It is the first ever detection of a gravitational wave source with an electromagnetic counterpart. It confirms that short gamma-ray bursts occur with neutron star mergers."

"It gives a new way of determining distances in cosmology. And it teaches us about the behaviour of matter with incredibly high density," he added.

Hawking also explained how important this discovery is for black hole physicists.

"The fact that a black hole can form from the merger of two neutron stars was known from theory. But this event is the first … observation," he said.

"The merger probably produces a rotating, hyper-massive neutron star which then collapses to form a black hole. This is very different from other ways of forming black holes, such as in a supernova or when a neutron star accretes matter from a normal star.

"With careful analysis of the data and theoretical modelling on supercomputers, there is vast scope for new insights to be obtained about the dynamics of black hole formation and gamma-ray bursts."

And finally, they finished the interview talking about gold and why it's so rare.

"The collision of neutron stars is one way of producing gold. It can also be formed from fast neutron capture in supernovas," Hawking said.

"Gold is rare everywhere, not just on Earth. The reason it's rare is that by nuclear-binding energy peaks at iron, making it hard to produce heavier elements in general."

We're sad Professor Hawking will no longer be around to interpret these amazing discoveries for us, but we are grateful for the many insights he brought on our Universe. The knowledge he has shared will continue to inspire us all, and provide strong foundations for the scientists following in his tracks.

You can read the whole interview over at the BBC.