Is interstellar travel currently possible, given what we know about the Universe and given our scientific and engineering knowhow?
In this podcast, NASA physicist Les Johnson discusses the science of interstellar travel, whether it's currently possible, and the challenges facing humanity as we seek to explore beyond our own Solar System.
Listen to this podcast and more via the Radio Astronomy Podcast page.
Iain Todd is BBC Sky at Night Magazine's Content Editor. He fell in love with the night sky when he caught his first glimpse of Orion, aged 10.