After an hour's Stargazing at Jodrell Bank, Dara O Briain and Brian Cox return to answer questions with the help of special guests including legendary Apollo 11 astronaut Buzz Aldrin. Plus Dr Lucie Green needs viewers' help to complete one of the toughest tasks in astronomy - the daunting Messier Challenge.

With the solar eclipse just hours away, Dara O Briain, Brian Cox and special guest experts are back at Jodrell Bank to answer viewers' questions. Apollo 11 astronaut Buzz Aldrin is on hand to explain why he believes humans must walk on the surface of Mars.

After the country stopped to enjoy the solar eclipse, Dara O Briain and Brian Cox are live at Jodrell Bank for a final 30 minutes of Stargazing to answer viewers' questions with the help of special guests. They also highlight the dates in 2015 when the night sky will provide the greatest show on Earth.