Guardian Science Weekly

Can a revolutionary new telescope solve the mystery of planet nine?

Loading player...
Ever since Pluto was demoted from planet to dwarf planet in 2006, astronomers have been wondering whether Neptune really is the most distant planet from the sun. Now, a new telescope could uncover what lies in the farthest reaches of the solar system. The Vera C Rubin Observatory released its first images this week, and soon the world’s most powerful digital camera will be pointing across the whole of the night sky. Scientists are hopeful that if planet nine exists, the telescope will find it within its first year of operation. Ian Sample is joined by Dr Scott Sheppard, an astronomer at the Carnegie Institution for Science, to find out how Pluto lost its planetary status, why scientists think there could be another super-Earth, and why planet nine has been so hard to find. Help support our independent journalism at theguardian.com/sciencepod
24 Jun 2025 English United Kingdom Science · Nature

Other recent episodes

100 years on Earth: celebrating David Attenborough’s birthday

To celebrate Sir David Attenborough’s centenary, Madeleine Finlay catches up with natural history writer Patrick Barkham, who has met the celebrated presenter. They explore how the natural world has changed in the century that Attenborough has been on Earth, and how his programming has reflected his growing commitment to highlighting…
7 May 20 min

Hantavirus explained: how does it spread and who is most at risk?

Three people have died after an outbreak of hantavirus onboard a cruise ship travelling from Argentina to Cape Verde. The World Health Organization says that a total of seven cases – two confirmed by laboratory testing and five suspected – have been identified on the cruise ship so far. They…
5 May 13 min

‘Historic breakthrough’: could the fossil fuel era be coming to an end?

The transition towards renewable energy received a boost last week when representatives from 57 countries met in Santa Marta, Colombia, for a world-first climate meeting aimed at bringing the fossil fuels era to an end. Madeleine Finlay hears from the Guardian’s global environment editor, Jon Watts, about how the landmark…
5 May 14 min

What is a food intolerance, and how do you know if you have one?

Social media is awash with content about food intolerances and the symptoms to look out for. But figuring out whether you actually have one, and what’s triggering it, is surprisingly difficult. One avenue people are gravitating towards is at-home testing. Madeleine Finlay sits down with health and lifestyle journalist Rebecca…
28 Apr 17 min
All episodes