With a mirror six and half metres in diameter, a sun shield the size of a tennis court and an instrument compartment bigger than a phone booth, the James Webb Space Telescope is enormous. After years of delays, it's now set for launch on December 22. We speak to two astronomers about the telescope and the questions they hope it will answer about the beginning of the universe and the conditions on exoplanets orbiting far-away stars. 

Featuring Martin Barstow, professor of astrophysics and space science at the University of Leicester in the UK and chair of the Space Telescope Science Institute Council; and Marcia Rieke, Regents professor of astronomy at the University of Arizona in the US and principal investigator on the near-infrared camera onboard the James Webb Space Telescope.

In our second story, Edwin Kwong, a research fellow at the University of Melbourne in Australia, explains his recent research into the tactics used by the food industry to boost sales of ultra-processed foods in middle-income countries. 

And Luthfi Dzulfikar, an editor for The Conversation in Jakarta, Indonesia recommends some analysis on the recent volcanic eruption on the island of Java.

The Conversation Weekly is produced by Mend Mariwany and Gemma Ware, with sound design by Eloise Stevens. Our theme music is by Neeta Sarl. You can sign up to The Conversation’s free daily email here. Full credits for this episode available here.

Further reading:

• James Webb Space Telescope: An astronomer on the team explains how to send a giant telescope to space – and why
• James Webb Space Telescope: what will happen after its launch? (in French)
• How big companies are targeting middle income countries to boost ultra-processed food sales
• Mount Semeru erupts: the history of its eruption (in Bahasa Indonesia)
• How religion influences Indonesian workers to seek work-life balance