🚀 go-pugleaf

In article <Qm$J2NAJCbUxEwt7@pipes.demon.co.uk>, Simon Pipe
<pipe@nc.bbc.co.uk> wrote:

> Hi.  I'm a producer at BBC Three Counties Radio (covering Bedfordshire,
> Hertfordshire and Buckinghamshire), and I need help with a question
> asked by one of our listeners.
> 
> He wants to know, HOW LONG WOULD IT TAKE TO VISIT EACH OF THE PLANETS IN
> OUR SOLAR SYSTEM IN TURN?
> 
> We have been challenged to find the answer on the Net.  I think I can
> guess at what *an* answer might be - there would seem to be certain
> variables - but would anyone be kind enough to: 
> 
> a) tell us the answer;
> b) give us an inspired and possibly even entertaining alternative; or
> c) add some (helpful) comments, either serious or even a bit frivolous.
> 
> Please, please e-mail any response to me at work - pipe@nc.bbc.co.uk -
> indicating whether your answer is known to be correct or just plain
> good-natured fun.  
> 
> We're doing this as part of Science Week in the UK.  If we decide we'd
> like to talk to you on air, I'll e-mail you and ask.  You can reply any
> way you like
> 
> Thanks, with love from Auntie .....
> 
> -- 
> Simon Pipe

Like visiting all of nine friends in turn, it's a matter of strict
organization. Moreover, contrary to friends, planets are always on the
move so you'd have to catch them as they go. Of course, if you just want
to wave hello from a fast-passing spacecraft you might make it in say
twenty years, provided you had almost unlimited fuel with you. Of course
gravity swingby might help with most of the planets but not with the
tricky one which is Mercury (because it's so close to the Sun, you need a
great velocity change, and because it's small it could only help little by
way of swingby). Say you start from Earth counting one planet, you take
three years out to Jupiter via Mars, then back in three years via Venus
and Mercury (4 and 5), around the Sun and out to Saturn, arrival four
years from the sun, and then all depends on the planets' positions but
leaving soon, you might make it in six more years via Uranus (7) to
Neptune (8) and another three to Pluto (9), altogether nineteen years.
Like Phileas Fogg, though, you'd depend on the right connections but it
just might work out.
If you want to rendezvous with all the nine, of course, organization
should include secrecy in the case of friends, and much more time and fuel
in the case of planets.
Then again, if you're a photon and someone holds up mirrors for you it'd
just take about a day! Which is a case for advanced propulsion.

Hope this helps,
Max

Simon Pipe <simon@pipes.demon.co.uk> wrote:

>Hi.  I'm a producer at BBC Three Counties Radio (covering Bedfordshire,
>Hertfordshire and Buckinghamshire), and I need help with a question
>asked by one of our listeners.

>He wants to know, HOW LONG WOULD IT TAKE TO VISIT EACH OF THE PLANETS IN
>OUR SOLAR SYSTEM IN TURN?

Of course the Voyager 2 deep space probe has half done this, it has
visited Earth (since it was launched from here) Jupiter, Saturn,
Uranus and Neptune over a period of about 12 years (1977-1989)

The answer also depends on what you mean by close, Voyager 2 passed by
all of them close (in astronomical terms) but not all that close by
your or my terms (I don't know the exact figures but I am guessing
that of the order of 1000-10000 miles would be the closest approach to
any of the planets - I think Neptune was the closest aside from the
Earth).

I don't think any other space probe has approached as many other
objects. Voyager 1 only went to Saturn and Jupiter, The Pioneer 10 and
11 did no better. I think Giotto observed (or was planned to) 3
differents objects (two comets and an asteriod ? possibly ?).

I reckon 56% of your targets in 12 years is not bad.
--
Tim Oddy    tim@flexagon.u-net.com    http://www.u-net.com/~flexagon
     (Very boring Web page, I must finish it !)

"If the apple won't fall, lets go and shake the tree." Sir Isacc Newton.