Re-entry for a spacecraft is presumably hard because the ship is going so fast and is slowed by the friction of the atmosphere.

Wouldn't it be a lot easier for the spacecraft if the retro-rockets were fired more fiercely and for much longer?  Is there a reason why this isn't done, apart from needing to carry more fuel? 

If in the far future, we manage to build two spaceships which can each travel at 75% of the speed of light, and then fly them in towards each other, people on each spaceship would see the other spaceship travelling at 1.5 times the speed of light towards them. How do we reconcile this with nothing being able to travel faster than the speed of light?

It seems morally reprehensible to be countenancing a branch of tourism that is so patently a monumental waste of precious resources when a) we are running out of fossil fuels, and b) global warming is a massive and present danger to our way of life. Or do rockets not use fossil fuels? If fabulously wealthy people insist on being space tourists, ought they to be issued with one-way tickets...?

If the earth is travelling through space at around 66 000 miles per hour,how would a spaceship returning to earth after a voyage actually "catch" us?  I mean that is one hell of a moving target to have to land on ..Yes i KNOW that once it is in its gravitational field then the rest is relative , but STILL   ..You leave earth on a long space voyage and when you get back it's NOT where you left it  but  Millions of miles away in space...possibly on the other side of the Sun... I suppose you would have to hang around in space  and wait for it to come past again and then kind of "jump on"    On the same subject...If you leave earth on a spaceship in the opposide direction from its orbital trajectory and look through the back window,, would you see earth zooming away from you into space at incredible speed? I mean...you are zooming away from Earth at 1000's of miles per hour and the earth is going the opposite way at 66000 m.p.h..same thing if you leave earth in the same direction as its orbital path...how would you get ahead of it???? once you left its gravitational field wouldn't it just ram you from behind if you are not travelling faster than 66 000 m.p.h.??

how do rockets with the force centred co much behind thir centre of mass manage to stay stable in the first few seconds before aerodynamics sorts it out

Although travelling at the speed of light is considered an impossibility jut hypthetically if you did look out the window of a spaceship whilst moving at lightspeed, what would you see?

If we hypothetically had the technology to travel 70 million light years away in an instant, along with some form of powerful telescope...when you looked at earth would you see earth as it was 70 million years ago, dinosaurs and all?

As I know there is no environment things like (sphere) in space, so how do we catch astronauts talking from earth to moon and in future mars to earth ? how signal travels in space? like sound waves!

These photos were taken in my parent's garden, Gloucestershire, during the snowy weather in January earlier this year.

The first photo shows the footprints starting near to the back door of their house, the second shows them making their way past the side of the house in a very straight line and the final photo shows them simply stopping.

We're still all very puzzled and wondered if anyone had any theories or ideas?