Jupiter

Philosophy...girlfriends... that sort of thing.
In theory it should be possible to see things that happened in the past. All you need is a rather big mirror, a rocket that travels faster than light and a good telescope.
Speed of light: 1079252848.8 km/h
Km. per hour if flying twice the speed of light: 2158505697.6 km/h
Distance to Jupiter: 965000000 km
Times you could fly to Jupiter in one hour: 2.24
So to fly to Jupiter would take you about: 27 minutes
The light would take about: 54 minutes
Time it would take the light to catch up with you: 27 minutes
So here you go with your supersonic rocket and your gigantic mirror that you can set up in 2 minutes... after 27 minutes the people left behind on planet earth could look back into time a fantastic 25 minutes! And the good news is: once you've got the mirror installed you can always look back 25 minutes! Voila, all possible crimes in the world (well, those that took place in open air and at the times when that side of planet earth was facing Jupiter) would be solved if someone looked through the telescope 27 minutes after the crime was committed. The start of a new era... Next we could install a mirror on a planet in another milkyway...and who knows: we just might see the first brick being laid of the Great Wall of China or we will finally find out how Napoleon really died. Hmm...bring it on!
I just realised though that we would have to wait another 185 years after the mirror has been installed before we could actually see the last mentioned event... So it would be a truly selfless thing to do, only the next generations would profit from it. Although, if we would travel there with our supersonic rocket at twice the speed of light and take a camera to record the events and then travel back to planet earth with the footage it would only take 92,5 years... there is a tiny little chance that some of us will still be around. Blahblahblah...