Scientists have discovered water on the sunlit surface of the Moon for the first time. Does it matter? Well, maybe it does. The Moon is back in vogue in terms of space exploration – the US says it will put astronauts back on the lunar surface by 2024. It is supposed to be the precursor to a manned mission to Mars. Stephen Sackur speaks to Jacob Bleacher, chief exploration scientist at NASA. In this time of pandemic and climate change here on Earth, is space exploration a potential lifeline or a massive vanity project?