Not sure if the ending is a bit weak. I did originally have a depressed Prof Cox slowly turning into Patrick Moore, set to the lovely tones of 'Life on Mars' but I couldn't get it to work or make sense 
1. PROF BRIAN COX IS IN HIS HOUSE READING A BOOK ABOUT SPACE WHEN THERE IS A KNOCK AT THE DOOR. A WOMAN (SHARON) IS THERE WITH HER LITTLE BOY (ERIC)
SHARON:
Oh hello. It's Professor Cox isn't it?. We've just moved in next door. We're huge fans.
THE BOY LOOKS VERY EMBARRASSED BY HIS MUMS FLIRTING
PROF COX:
That's very kind of you. Glad you like my shows. And please, call me Brian.
THE BOY TUGS HIS MUMS SLEEVE
SHARON:
What? Oh yes, sorry Brian, this is my son Eric. He's mad keen on astronomy. I'm sorry to be cheeky, but he's dying to show you something.
PROF COX:
Of course. What is it Eric? A drawing of the moon? Have you made a telescope from toilet rolls?
ERIC WALKS OVER TO THE GARDEN. PROF COX FOLLOWS HIM. ERIC POINTS AT THE GRASS
ERIC:
I think I've found a wormhole.
PROF COX LAUGHS, NOT IN AN UNKIND WAY
PROF COX:
Eric, this isn't a hypothetical topological feature of spacetime. It's just a normal wormhole, made by (beat) worms.
SHARON SMILES AND WRAPS HER ARMS AROUND ERIC
PROF COX:
Don't worry. At least he's enthusiastic. Hey Eric, perhaps I can show you some planets one evening? It's supposed to be clear over the next few nights.
FADE
2. INT PROF COX'S HOUSE. THERE IS A KNOCK AT THE DOOR. PROF COX OPENS IT TO FIND ERIC ON HIS OWN
PROF COX:
Hello Eric. How are you?
ERIC:
I think I've found some dark matter.
ERIC HANDS PROF COX SOME TOAST. PROF COX SMELLS IT AND SMILES
PROF COX:
It's Marmite Eric, not some elusive substance that's inferred to exist from gravitational effects on visible matter. Is everything ok at home Eric?
ERIC WALKS OFF
FADE
3. INT PROF COX'S HOUSE. THERE IS A KNOCK AT THE DOOR AGAIN. ERIC IS STANDING NEXT TO A HUGE MAN. WE CAN ONLY SEE HIS FEET. PROF COX LOOKS UP A BIT CONFUSED.
ERIC:
Show him
THE LARGE MAN LETS OUT A LOUD BURP
PROF COX:
Eric this is just a normal, human gassy giant, not a huge, celestial body with an extremely thick atmosphere and a molten core.
FADE
4. INT PROF COX'S HOUSE. KNOCK ON HIS DOOR AGAIN. ERIC IS HOLDING A PICTURE OF CHARLTON HESTON.
PROF COX:
Well, it's not really a shooting star in the traditional sense.
ERIC:
I hate you. I'm never thinking about space again.
FADE
5. EXT PROF COX'S HOUSE. ERIC IS WALKING ALONG LOOKING MISERABLE. A MAN APPROACHES HIM AND ASKS HIM WHICH PLANET THIS IS. ERIC LOOKS UP AND SEES THE MAN HAS A BRIGHT GREEN FACE.
ERIC:
Earth.
ERIC JUST WALKS OFF LEAVING THE ALIEN SLIGHTLY SHOCKED AT HIS ABRUPTNESS. AS HE DOES SO WE SEE THE WORDS 'SCIENCE STINKS' ON THE BACK OF HIS T-SHIRT