What to watch on TV tonight from Human Universe to The Children in Need Sewing Bee

9pm, BBC2

“If the universe has thrown up one intelligent civilisation, why not another?”, muses Brian Cox as this week he asks: are we alone? In 1977, listeners at Ohio’s Big Ear project, which activelyscours the heavens for signals of alien life, thought not when, in 1977, they detected the “Wow! signal” – a 72-second radio signal from outer space.

8pm, BBC2

A dozen “celebrities” (starting with the television presenter Dawn Harper, Hairy Biker Dave Myers, the DJ/presenter Edith Bowman and the actor Wendi Peters) take to their sewing machines in aid of charity.

9pm, Channel 4

“I’m looking for someone who can basically be me, but not sleep with my husband,” says one of the prospective new employers in this new series whose modus operandi is to follow those applying for domestic service jobs through adverts placed in The Lady magazine. Of course, the fun here is the aristocrats submitting themselves to the camera, including a splendidly blunt Russian princess seeking a gardener for her Kent home and a Northumberland-based baronet looking for someone to polish his armoury.

9pm & 2.55am, BBC4

Dan Cruickshank follows the rise and fall of Sir George Gilbert Scott, his son George Junior, and grandson Giles – the dynasty responsible for (among much else) the Midland Hotel at London’s St Pancras station., the Albert Memorial, Liverpool Cathedral and Battersea Power Station.

10pm, BBC2

U2 make their debut on the show with material from their new album Songs of Innocence. Also on the bill are the singer Sam Smith and New York rockers rockers Interpol.