can i stick my arm out the plane window?

Okay, so I'm going on vacation to Australia in 3 days, and it's going to be an overnight flight, so since at night time there is usually stars out I figured since I'm going to be in an aeroplane which flies like 30,000 feet in the air, therefore I will be much closer to the stars, do you think if I asked the pilot nicely he would let me open my window so I could stick my arm out to grab a few stars and maybe some cloud? I've always wanted to do this, my friend said he did it once. Also I figured it would save me buying presents for people back home I could just give them stars and cloud bits, so this is possible right?