Ever wondered how much it is to send a letter to Mars?
Well a five-year-old boy who dreams of becoming an astronaut has found out - it will set you back nearly £12,000.
Oliver Giddings, from Lancashire, wrote to Royal Mail with the unique request.
Staff, with the help of Nasa Kennedy Space Centre in Florida, told Oliver that a letter with a "normal" weight would cost £11,602.25 to send the 567 million kilometres from Earth to Mars and back.
That is the equivalent of 18,416 first class stamps or 21,466 second class stamps.
"Wow! That's a lot of money - you would need so many stamps!" Oliver said in his reply to Royal Mail.
Oliver's mother, Melanie Giddings, said "he has always been an inquisitive little boy and is very keen on anything to do with space, stars and planets.
"He was so excited to get such a great letter back from Royal Mail".