Nearly two thirds of UK children puzzle their parents with complex science questions, leaving them "frustrated and embarrassed", a report championed by Professor Brian Cox revealed.

Conducted by The Big Bang Fair, the study questioned 2,000 parents and found almost one in three were subjected to a grilling by their children on a daily basis, filling 52% of parents "with fear".

The questioned which left parents the most vexed were:

• Why is the moon sometimes out in the day?
• Why is the sky blue?
• Will we ever discover aliens?
• How much does the earth weigh?
• How do aeroplanes stay in the air?

While a third of parents engage in research in order to answer their children's questions, 21% make up the answers or pretend "nobody knows" and one in six pass the burden onto their partner.

Professor Brian Cox, spokesman for and supporter of The Big Bang, said with more and more children getting "stuck in" to science and maths it was "no wonder" they were constantly questioning the world.

"Inquisitive minds are fantastic, but clever questions can often leave parents in a tricky situation if they don’t have the answers.

“The best thing parents can do is work with their children to find the answers – not only can it be fun, but you’ll both learn something new along the way," he added.

And in order to give parents a helping hand, the Big Bang answered some of the queries which most confounded parents:

1. Why is water wet?
"Wetness is just a feeling. It’s something that our brains tell us about what we’re touching. It is a combination of temperature, pressure and the way it moves which tells our brains that water is wet."

2.Why is the sky blue?
"If you’re stuck on this one, then you’re in good company – it even stumped Aristotle and Isaac Newton.

"White sunlight is really a lot of different colours of light mixed together. Light passing through the sky bounces off particles in the air and some colours of light travel through air and dust better than others. The blue light gets bounced around the most, so whatever direction you look at you see a blue colour."

3. Will we ever discover aliens?
"The fact is, nobody knows the answer to this question. We know for sure that no life exists in our solar system, and the closest galaxy to ours is trillions of miles away, so no human can survive a trip that far."