Mission to Mars

[Lakitu]

http://news.bbc.co.uk/1/hi/sci/tech/7411113.st m

How are the astonauts on Pheonix able to communicate and send photo's to Earth from so far away?

My mind is most likely oversimplifying the matter, but why is it if I go deep into the Countryside, my phone loses its signal yet they are 423 million miles away and don't seem to have this problem? I realise that the difference in technology between my phone and their equipment is probably the difference between night and day, but I still need a some kind of communication mast within range in order to do anything, I'm guessing there are no masts on Mars....

Also, when it's explained to me how it's done, can you tell me how long it would take for Earth to receive the communication? Would it be almost instantaneous or take a few hours?

[vehelpfulguy]

>How are the astonauts on Pheonix

You are joking of course, there are no people on board the mars probe.

[Dr-Legend]

The mission is to try to find our descendants.The ones who came 2,000 years ago and landed in bethlehem.They left one of their kind and he was called jesus.
They later returned and took him away after he was crucified.
They said theyd return.
And they shall

[Lakitu]

LMAO!

Well, that explains my thought "Gosh, they must have been bored on that thing for 10 months!". In my defense, it didn't say there WASN'T people on it.....

So, the communication question still stands.

[beso]

Directional antenna.

The antenna on the space vehicle is a parabolic dish. The transmissions form a beam that is directed toward the earth. The distance to Mars is no problem. Indeed the first Voyager space craft is now over 15 billion kilometres away and still in contact even though it takes more than 13 hours for the signal to get here.

The mobile phone system uses omnidirectional antenna so the signal weakens with distance. Also on earth you have the curve of the surface and various geographical obstructions to block the signal. There is virtually nothing in the way bar the odd molecule out in space.

The signals travel at the speed of light (300,000 kilometres per second) and the time it take from Mars depends on the relative position of th orbits of Earth and Mars. The shortest separation is 57 million kilometres and the longest about 400 million kilometres. It takes between three and twenty minutes for the signal to travel.

[Lakitu]

Thank you very much, beso! x