-- that  was the trouble. He no  longer had  arty  purpose in
life. And the weight of too many memories was upon him; echoing the title of
a famous book he had read in his  youth,  he often said  to himself, 'I am a
Stranger in a Strange Time.'
     There were even occasions when he looked  down at  the beautiful planet
on which -- if  he obeyed  doctor's orders -- he could never walk again, and
wondered what it would be like to make a second acquaintance with the vacuum
of  space.  Though  it was not  easy to  get  through  the  airlocks without
triggering  some alarm, it  had been done:  every few years, some determined
suicide made a brief meteoric display in the Earth's atmosphere.
     Perhaps  it was  just as  well  that deliverance was on its way, from a
completely unexpected direction.

        x x x
     'Nice to meet you, Commander Poole -- for the second time.'
     'I'm sorry -- don't recall -- but then I see so many people.'
     'No need to apologize. First time was out round Neptune.'
     'Captain Chandler -- delighted to see you! Can I get something from the
autochef?'
     'Anything with over twenty per cent alcohol will be fine.'
     'And  what are you  doing  back on Earth? They told me you  never  come
inside Mars orbit.'
     'Almost true --  though I was born here,  I think it's a  dirty, smelly
place -- too many people -- creeping up to a billion again!'
     'More than  ten billion in my time. By the  way,  did you get my "Thank
you" message?'
     'Yes --  and I know I  should have contacted you. But I  waited until I
headed sunwards again. So here I am. Your good health!'
     As the Captain disposed of his drink with impressive speed, Poole tried
to analyse his visitor. Beards -- even small goatees like Chandler's -- were
very rare in this society, and he had never known an astronaut who wore one:
they  did not co-exist comfortably  with space-helmets. Of course, a Captain
might go for years between EVs, and in any case most  outside jobs were done
by robots; but there was  always the risk of the unexpected, when  one might
have to get suited in a hurry. It was obvious that Chandler was something of
an eccentric, and Poole's heart warmed to him.
     'You've not answered my question. If you don't like Earth, what are you
doing here?'
     'Oh,  mostly  contacting  old  friends  --  it's  wonderful  to  forget
hour-long delays,  and to have real-time conversations! But of course that's
not the  reason.  My  old rust-bucket  is  having a  refit,  up  at  the Rim
shipyard. And the armour  has  to be replaced; when it  gets  down to a  few
centimetres thick, I don't sleep too well.'
     'Armour?'
     'Dust shield. Not such a problem in your time, was it? But it's a dirty
environment  out  round  Jupiter,  and  our normal cruise speed  is  several
thousand klicks  -- a second! So there's a continuous gentle pattering, like
raindrops on the roof.'
     'You're joking!'
     'Course I am. If we really could  hear anything, we'd be dead. Luckily,
this sort of unpleasantness is very rare -- last serious accident was twenty
years  ago.  We know all the main comet streams,  where most of the junk is,
and are careful  to  avoid them  -- except when we're  matching velocity  to
round up ice.
     'But why don't you come aboard and have a  look around, before  we take
off for Jupiter?'
     'I'd be delighted... did you say Jupiter?'
     'Well, Ganymede,  of  course --  Anubis City. We've  a lot  of business
there, and several of us have families we haven't seen for months.'
     Poole scarcely heard him.
     Suddenly -- unexpectedly --  and perhaps none too  soon, he had found a
reason for living.
     Commander  Frank  Poole  was the sort  of man who hated to  leave a job
undone -- and  a few specks of  cosmic  dust,  even  moving  at  a  thousand
kilometres a second, were not likely to discourage him.
     He had unfinished business at the world once known as Jupiter.

        II GOLIATH

     14 A Farewell to Earth

     'Anything you want  within reason,' he  had been told.  Frank Poole was
not  sure  if  his  hosts would consider  that returning to  Jupiter  was  a
reasonable request; indeed, he was not quite sure himself, and was beginning
to have second thoughts.
     He had already  committed  himself to scores  of engagements,  weeks in
advance. Most of them  he  would be happy to  miss,  but there were some  he
would be  sorry to forgo. In particular, he hated  to disappoint the  senior
class from his old high school -- how  astonishing that it still existed! --
when they planned to visit him next month.
     However, he was relieved --  and a  little surprised -- when both Indra
and  Professor Anderson agreed that  it was an excellent idea. For the first
time, he  realized  that they  had been  concerned  with his  mental health;
perhaps a holiday from Earth would be the best possible cure.
     And,  most important of all, Captain Chandler  was delighted. 'You  can
have  my cabin,' he promised. 'I'll kick the First Mate out of hers.'  There
were times when  Poole wondered if Chandler, with his beard and swagger, was
not  another anachronism.  He could  easily  picture  him on the bridge of a
battered three-master, with Skull and Crossbones flying overhead.
     Once his decision had been made, events moved with surprising speed. He
had accumulated very few possessions, and fewer still that he needed to take
with him. The most important was Miss Pringle, his  electronic alter ego and
secretary, now the  storehouse of  both his  lives, and  the  small stack of
terabyte memories that went with her.
     Miss Pringle was not much larger than the hand-held personal assistants
of  his  own  age, and usually lived,  like  the  Old West's Colt  45, in  a
quick-draw holster at  his waist. She could communicate with him by audio or
Braincap, and  her  prime  duty  was to act as an information filter  and  a
buffer to the  outside world.  Like  any good  secretary,  she knew  when to
reply, in the appropriate format: 'I'll put you through now' or -- much more
frequently: 'I'm  sorry -- Mr  Poole is engaged. Please record your  message
and he will get back to you as soon as possible.' Usually, this was never.
     There were very few farewells to be made: though realtime conversations
would be impossible owing  to the sluggish velocity of radio waves, he would
be  in  constant touch with Indra and Joseph -- the  only genuine friends he
had made.
     Somewhat  to  his  surprise,  Poole  realized  that  he would miss  his
enigmatic but useful 'valet', because he would now  have  to handle  all the
small  chores of  everyday life by himself.  Danil  bowed slightly when they
parted, but otherwise showed no sign of emotion, as they took the  long ride
up  to  the outer  curve of the  world-circling  wheel, thirty-six  thousand
kilometres above central Africa.

     'I'm  not sure, Dim, that you'll appreciate the comparison. But do  you
know what Goliath reminds me of?'
     They  were now such good  friends that  Poole  could use  the Captain's
nickname -- but only when no one else was around.
     'Something unflattering, I assume.'
     'Not really. But when I was a  boy, I  came across a whole pile  of old
science-fiction  magazines that  my Uncle  George had abandoned --  "pulps",
they were called, after the cheap paper they were printed on... most of them
were  already  falling  to  bits. They had wonderful garish  covers, showing
strange planets and monsters -- and, of course, spaceships!
     'As I grew older, I realized how ridiculous those spaceships were. They
were  usually rocket-driven  --  but  there was never any sign of propellant
tanks! Some of  them had rows of windows from stem to stem,  just like ocean
liners.  There  was  one  favourite  of  mine  with a  huge  glass dome -- a
space-going conservatory...
     'Well,  those old artists had the last laugh:  too bad they could never
know. Goliath looks  more like their dreams than  the  flying fuel-tanks  we
used to launch from the Cape.
     Your Inertial Drive still seems too good to be true -- no visible means
of support, unlimited range and speed -- sometimes I think I'm the one who's
dreaming!'
     Chandler laughed and pointed to the view outside.
     'Does that look like a dream?'
     It was the first  time that Poole had seen a genuine horizon  since  he
had come to Star City, and it was not quite as far away as he  had expected.
After  all, he was on the outer rim of  a wheel  seven times the diameter of
Earth,  so surely the view across the  roof of  this artificial world should
extend for several hundred kilometres...
     He used to be good at  mental arithmetic --  a rare achievement even in
his  time, and  probably  much rarer  now. The  formula to give  the horizon
distance was a simple one:  the square root of  twice your height  times the
radius -- the sort of thing you never forgot, even if you wanted to...
     Let's see -- we're about 8 metres up -- so root 16 -- this is easy!  --
say big R  is 40,000 -- knock off those three zeros to make it all klicks --
4 times root 40 -- hmm -- just over 25...
     Well,  twenty-five kilometres was a fair  distance,  and  certainly  no
spaceport  on  Earth had ever seemed this huge.  Even knowing perfectly well
what to  expect, it was uncanny to watch vessels many  times the size of his
long-lost  Discovery  lifting  off,  not only  with no  sound, but  with  no
apparent means of propulsion. Though Poole missed the flame and  fury of the
old-time countdowns, he  had to admit that this was cleaner,  more efficient
-- and far safer.
     Strangest  of  all, though, was  to  sit  up here  on the Rim,  in  the
Geostationary Orbit itself -- and to  feel weight! Just metres away, outside
the window  of  the tiny  observation lounge,  servicing robots  and  a  few
spacesuited humans were gliding gently about their business; yet here inside
Goliath the inertial field was maintaining standard Mars-gee.
     'Sure you don't want to  change your mind, Frank?' Captain Chandler had
asked jokingly,  as  he left  for  the  bridge. 'Still  ten  minutes  before
lift-off.'
     'Wouldn't be  very popular if I did, would I? No -- as they used to say
back in the old days -- we have commit. Ready or not, here I come.'
     Poole felt the  need to be alone when  the  drive went on, and the tiny
crew --  only four men and  three women -- respected his wish.  Perhaps they
guessed  how he must be feeling,  to leave Earth  for the  second time  in a
thousand years -- and, once again, to face an unknown destiny.
     Jupiter-Lucifer was on the  other  side  of  the  Sun,  and the  almost
straight line  of  Goliath's orbit  would  take  them  close to Venus. Poole
looked  forward to seeing, with his  own  unaided  eyes, if  Earth's  sister
planet  was now beginning to live up to that description, after centuries of
terraforming.
     From  a thousand kilometres up, Star City  looked like a gigantic metal
band   around  Earth's  Equator,  dotted  with  gantries,  pressure   domes,
scaffolding holding half-completed ships, antennas, and other more enigmatic
structures.  It was diminishing  swiftly  as  Goliath headed  sunwards,  and
presently Poole could  see  how  incomplete it was:  there  were  huge  gaps
spanned only by a spider's web of scaffolding, which would probably never be
completely enclosed.
     And now they were falling below the plane of the ring; it was midwinter
in the  northern  hemisphere, so the slim halo of Star  City was inclined at
over twenty degrees  to the Sun. Already  Poole  could see  the American and
Asian  towers, as shining  threads stretching  outwards and away, beyond the
blue haze of the atmosphere.
     He was barely  conscious of time as  Goliath gained speed,  moving more
swiftly  than  any comet  that  had ever  fallen  sunwards from interstellar
space. The Earth, almost full, still spanned his field of view, and he could
now  see the full length of the  Africa Tower which had been his home in the
life he was now leaving --  perhaps, he could not help thinking, leaving for
ever.
     When they were fifty thousand kilometres out, he  was  able to view the
whole of  Star City, as a narrow ellipse enclosing the Earth. Though the far
side was barely  visible, as a  hair-line of light against the stars, it was
awe-inspiring  to think  that the human race had now set  this sign upon the
heavens.
     Then Poole remembered  the rings  of  Saturn, infinitely more glorious.
The astronautical engineers still had a long, long way  to  go, before  they
could match the achievements of Nature.
     Or, if that was the right word, Deus.

     15 Transit of Venus

     When he woke the  next  morning, they were  already at  Venus. But  the
huge, dazzling crescent of the still cloud-wrapped planet was  not the  most
striking object in the sky:
     Goliath was floating  above an endless expanse of crinkled silver foil,
flashing in the sunlight with  ever-changing  patterns as the  ship  drifted
across it.
     Poole remembered that  in his own age there had been an artist  who had
wrapped  whole buildings in plastic  sheets: how  he  would have loved  this
opportunity to  package billions of  tons of ice in a glittering envelope...
Only in this way could the core of a comet be protected from evaporation  on
its decades-long journey sunwards.
     'You're in luck, Frank,' Chandler had told him. 'This is something I've
never  seen  myself. It should  be  spectacular. Impact due  in just over an
hour. We've given it a little nudge, to make sure it comes down in the right
place. Don't want anyone to get hurt.'
     Poole looked at him in astonishment.
     'You mean -- there are already people on Venus?'
     'About fifty mad  scientists, near the South Pole.  Of course,  they're
well dug in, but we should shake them up a bit -- even though Ground Zero is
on  the other  side of the planet. Or I should say "Atmosphere Zero"  --  it
will be days before anything except the shockwave gets down to the surface.'
     As  the  cosmic  iceberg,  sparkling  and flashing  in  its  protective
envelope,  dwindled  away  towards Venus,  Poole  was struck with  a sudden,
poignant memory. The Christmas trees of his childhood  had been adorned with
just such ornaments, delicate bubbles of coloured glass. And the  comparison
was not completely ludicrous: for many families on Earth, this was still the
right  season for gifts, and Goliath was bringing a present beyond price  to
another world.
     The  radar  image of  the tortured  Venusian  landscape  --  its  weird
volcanoes, pancake domes, and  narrow, sinuous canyons -- dominated the main
screen of Goliath's control centre, but Poole preferred  the evidence of his
own eyes.  Although the unbroken  sea  of  clouds that  covered  the  planet
revealed nothing of the inferno beneath, he wanted to see  what would happen
when the stolen comet struck. In a matter of seconds, the myriad of  tons of
frozen  hydrates that had been gathering  speed for decades on the  downhill
run from Neptune would deliver all their energy...
     The  initial flash was  even brighter than he had expected. How strange
that a missile made of ice could generate temperatures that must  be in  the
tens of thousands of degrees! Though the filters of the view-port would have
absorbed all  the  dangerous shorter wave-lengths, the  fierce blue  of  the
fireball proclaimed that it was hotter than the Sun.
     It was cooling rapidly as it expanded -- through yellow, orange, red...
The shockwave would now  be spreading outwards  at the velocity  of sound --
and what a sound  that must be! -- so in a few minutes  there should be some
visible indication of its passage across the face of Venus.
     And there it  was! Only a tiny black ring -- like an insignificant puff
of smoke, giving no hint of the cyclonic fury that must  be blasting its way
outwards from the  point of impact.  As Poole watched,  it  slowly expanded,
though owing to its scale  there was no sense of visible movement: he had to
wait for  a full  minute before he could be  quite sure  that  it  had grown
larger.
     After a quarter of  an hour, however, it was the most prominent marking
on the planet. Though much fainter -- a dirty grey, rather than black -- the
shockwave was now a ragged  circle more  than a thousand  kilometres across.
Poole guessed that it had lost its original symmetry while sweeping over the
great mountain ranges that lay beneath it.
     Captain  Chandler's  voice  sounded  briskly  over  the ship's  address
system.
     'Putting  you through  to  Aphrodite  Base.  Glad  to say  they're  not
shouting for help --'
     '- shook us up a bit, but just what we expected. Monitors indicate some
rain  already  over the  Nokomis Mountains --  it will  soon  evaporate, but
that's  a beginning. And there seems to  have been a  flash-flood  in Hecate
Chasm -- too good to be true, but we're checking. There was a temporary lake
of boiling water there after the last delivery --'
     I don't envy  them, Poole told himself  -- but I certainly admire them.
They  prove  that  the  spirit  of  adventure  still exists  in this perhaps
too-comfortable and too-well-adjusted society.
     '- and thanks again for  bringing  this little  load down in  the right
place. With any luck -- and if we can get that sun-screen up into sync orbit
-- we'll have some permanent seas before long. And  then we can plant  coral
reefs, to make lime and pull the excess CO2 out of  the atmosphere -- hope I
live to see it!'
     I  hope you  do, thought Poole in silent admiration. He had often dived
in  the tropical seas of Earth, admiring weird  and colourful  creatures  so
bizarre that it was hard  to believe anything stranger would be found,  even
on the planets of other suns.
     'Package  delivered  on time, and receipt acknowledged,'  said  Captain
Chandler  with  obvious satisfaction.  'Goodbye Venus -- Ganymede,  here  we
come.'

        MISS PRINGLE
        FILE WALLACE
     Hello,  Indra.  Yes,  you  were  quite  right.  I  do  miss  our little
arguments. Chandler and I  get along fine,  and at first the crew treated me
-- this will amuse you -- rather like a holy relic. But they're beginning to
accept me, and have even started to pull my leg (do you know that idiom?).
     It's  annoying  not to  be able to have  a  real conversation  -- we've
crossed the orbit of Mars, so radio round-trip is already over an  hour. But
there's one advantage -- you won't be able to interrupt me...
     Even though it will take us only a week to reach Jupiter, I thought I'd
have  time  to relax. Not  a  bit  of it: my fingers started to itch,  and I
couldn't resist going back to school. So I've begun basic training, all over
again,  in one of Goliath's  minishuttles. Maybe  Dim  will actually  let me
solo...
     It's  not much bigger than  Discovery's pods  -- but what a difference!
First of all, of course, it  doesn't  use rockets: I can't  get used to  the
luxury of  the inertial drive, and unlimited range. Could fly back to  Earth
if I had to  -- though I'd probably get -- remember the phrase I  used once,
and you guessed its meaning? -- 'stir crazy'.
     The biggest difference, though, is the control system. It's  been a big
challenge for me to get used  to hands-off operation -- and the computer has
had to  learn to  recognize my voice commands.  At first it was asking every
five minutes 'Do you really mean that?' I know it would be better to use the
Braincap -- but  I'm  still not  completely confident  with that gadget. Not
sure if I'll ever get used to something reading my mind.
     By the way, the shuttle's called  Falcon. It's a nice name -- and I was
disappointed to find that no one aboard  knew that it  goes all the way back
to the Apollo missions, when we first landed on the Moon...
     Uh-huh --  there  was a  lot more  I wanted to say, but the  skipper is
calling. Back to the classroom -- love and out.
        STORE
        TRANSMIT

     Hello Frank  -- Indra  calling -- if that's  right  word!  -- on my new
Thoughtwriter  --  old one had  nervous  breakdown  ha ha  --  so be lots of
mistakes -- no time to edit before I send. Hope you can make sense.
     COMSET! Channel one oh three -- record from twelve thirty -- correction
-- thirteen thirty. Sorry...
     Hope I can get old  unit fixed -- knew  all my short-cuts and abbrieves
-- maybe should get psychoanalysed like in your time -- never understood how
that Fraudian -- mean Freudian ha ha -- nonsense lasted as long as it did --
Reminds me -- came across late Twentieth defin other day -- may amuse you --
something  like  this   --  quote  --Psychoanalysis  --  contagious  disease
originating  Vienna  circa 1900  -- now  extinct  in  Europe but  occasional
outbreaks among rich Americans. Unquote. Funny?
     Sorry again -- trouble  with Thoughtwriters  -- hard to stick  to point
--xz 12€ w 888 5***** js98l2yebdc DAMN... STOP BACKUP
     Did I do something wrong then? Will try again.  You mentioned  Danil...
sorry we always evaded  your questions about him --  knew you were  curious,
but we had very good reason -- remember you once called him a non-person?...
not bad guess...!
     Once you  asked  me about  crime nowadays -- I said  any  such interest
pathological  --  maybe   prompted  by  the  endless  sickening   television
programmes of your  time --  never  able  to  watch  more  than  few minutes
myself... disgusting!
        DOOR ACKNOWLEDGE! OH, HELLO MELINDA EXCUSE SIT DOWN NEARLY FINISHED...
     Yes -- crime. Always some... Society's irreducible noise level. What to
do?
     Your  solution  --  prisons.  State-sponsored perversion  factories  --
costing ten times average family income to hold one inmate! Utterly crazy...
Obviously  something very  wrong with people who  shouted  loudest  for more
prisons --  They should  be  psychoanalysed! But let's  be fair -- really no
alternative before electronic monitoring and control perfected -- you should
see  the joyful crowds smashing the prison  walls  then  -- nothing like  it
since Berlin fifty years earlier!
     Yes -- Danil. I don't know what his crime was -- wouldn't tell you if I
did -- but presume his psych profile suggested he'd make a good  -- what was
the  word?  -- ballet -- no, valet. Very hard to get people for some jobs --
don't  know  how  we'd manage if  crime  level zero!  Anyway hope he's  soon
decontrolled and back in normal society
        SORRY MELINDA NEARLY FINISHED
     That's  it, Frank  -- regards  to Dimitrj  -- you must  be  halfway  to
Ganymede now -- wonder if they'll ever repeal Einstein so we can talk across
space in real-time!
     Hope this machine soon gets used to me. Otherwise be looking round  for
genuine antique  twentieth century word  processor... Would  you believe  --
once  even mastered that  QWERTYIYUIOP nonsense, which you took a couple  of
hundred years to get rid of?
     Love and good-bye.

        x x x

     Hello Frank --  here  I am again. Still  waiting  acknowledgement of my
last...
     Strange you should be heading towards  Ganymede, and my  old friend Ted
Khan. But  perhaps it's  not such a coincidence: he  was  drawn by the  same
enigma that you were...
     First I must  tell you  something about him. His parents played a dirty
trick, giving him the name Theodore. That  shortens --  don't ever  call him
that! -- to Theo. See what I mean?
     Can't help wondering if that's what drives  him. Don't know anyone else
who's developed such an  interest in religion  -- no, obsession. Better warn
you; he can be quite a bore.
     By the way, how am I doing? I miss  my old  Thinkwriter, but seem to be
getting  this  machine  under control. Haven't made any bad --  what did you
call  them? -- bloopers -- glitches -- fluffs -- so far at least -- Not sure
I should  tell you  this,  in case  you accidentally blurt  it  out, but  my
private nickname for Ted is 'The Last Jesuit'. You must know something about
them -- the Order was still very active in your time.
     Amazing  people  -- often great scientists -- superb scholars  -- did a
tremendous amount  of  good as  well  as much harm. One of history's supreme
ironies --  sincere and  brilliant seekers of knowledge and truth, yet their
whole philosophy hopelessly distorted by superstition...
     Xuedn2k3jn deer 2leidj dwpp
     Damn. Got emotional and lost control.  One, two, three, four...  now is
the time for all good men to come to the aid of the party... that's better.
     Anyway, Ted has that same brand of high-minded determination; don't get
into any arguments with him -- he'll go over you like a steam-roller.
     By the  way what were steam-rollers? Used for pressing clothes? Can see
how that could be very uncomfortable...
     Trouble with Thinkwriters... too easy  to  go off in all directions, no
matter  how hard  you try to discipline yourself... something to be said for
keyboards after all... sure I've said that before...
     Ted Khan... Ted Khan... Ted Khan
     He's  still famous  back on  Earth  for  at  least two of his  sayings:
'Civilization and Religion  are incompatible' and  'Faith is  believing what
you know isn't true'. Actually, I don't  think the last one is  original; if
it is, that's the nearest  he ever got  to  a joke. He never cracked a smile
when I  tried  one  of  my favourites  on  him -- hope you haven't  heard it
before. It obviously dates from your time.
     The Dean's complaining to his Faculty. 'Why do you scientists need such
expensive equipment? Why can't  you be like the Maths Department, which only
needs  a  blackboard and  a  waste-paper  basket?  Better  still,  like  the
Department  of Philosophy.  That doesn't even need  a wastepaper  basket...'
Well, perhaps Ted had heard it before... I expect most philosophers have...
     Anyway, give  him my regards --  and  don't, repeat don't, get into any
arguments with him!

     Love and best wishes from Africa Tower.
        TRANSCRIBE STORE
        TRANSMIT POOLE

     16 The Captain's Table

     The arrival  of  such a  distinguished  passenger had caused  a certain
disruption in the tight little world of Goliath, but the crew had adapted to
it with good humour. Every day, at 18.00 hours, all  personnel gathered  for
dinner in the wardroom, which in zero-gee could hold at  least thirty people
in comfort, if spread uniformly around the walls. However, most of the  time
the  ship's working areas  were  held at  lunar gravity,  so  there  was  an
undeniable floor -- and more than eight bodies made a crowd.
     The semi-circular table that unfolded around the auto-chef at mealtimes
could just seat the entire seven-person crew, with the Captain at  the place
of honour. One extra created such insuperable problems that somebody now had
to eat alone for every meal. After  much good-natured debate, it was decided
to make  the choice in alphabetical order -- not of proper names, which were
hardly ever used, but of nicknames. It had taken Poole some time to get used
to   them:  'Bolts'   (structural  engineering);  'Chips'   (computers   and
communications);  'First'  (First  Mate);  'Life'  (medical and life-support
systems);   'Props'  (propulsion  and   power);  and  'Stars'   (orbits  and
navigation).
     During the ten-day  voyage,  as  he listened to  the stories, jokes and
complaints of  his  temporary shipmates, Poole learned  more about the solar
system than  during his months on Earth. All aboard were obviously delighted
to have a  new and perhaps naÎve listener as an attentive  one-man audience,
but Poole was seldom taken in by their more imaginative stories.
     Yet sometimes it was hard to know where to draw the line. No one really
believed   in  the  Golden  Asteroid,  which   was  usually  regarded  as  a
twenty-fourth-century hoax. But  what about  the Mercurian plasmoids,  which
had  been reported by  at least a dozen reliable  witnesses during  the last
five hundred years?
     The simplest explanation was  that they were related to ball-lightning,
responsible for so many 'Unidentified Flying  Object'  reports  on Earth and
Mars. But  some observers swore that they had shown purposefulness  --  even
inquisitiveness  -- when they were encountered at close  quarters. Nonsense,
answered the sceptics -- merely electrostatic attraction!
     Inevitably, this led to  discussions about life  in the  Universe,  and
Poole  found  himself  -- not  for the  first time  --defending his  own era
against its extremes of credulity and scepticism. Although  the  'Aliens are
among  us' mania had already subsided when he was a boy, even as late as the
2020s the  Space Agency  was still plagued  by lunatics who  claimed to have
been contacted  --  or  abducted  --  by  visitors from other worlds.  Their
delusions  had been reinforced by  sensational media  exploitation,  and the
whole syndrome was  later enshrined in the medical literature  as 'Adamski's
Disease'.
     The discovery of TMA ONE  had, paradoxically, put an  end to this sorry
nonsense,  by  demonstrating  that  though  there  was  indeed  intelligence
elsewhere,  it had apparently not  concerned itself with Mankind for several
million  years.  TMA  ONE  had  also  convincingly  refuted  the  handful of
scientists who  argued  that life  above  the  bacterial level  was  such an
improbable phenomenon that the human race was alone in this Galaxy -- if not
the Cosmos.
     Goliath's crew was more  interested in the technology than the politics
and  economics  of  Poole's  era,  and  were particularly fascinated by  the
revolution  that  had  taken place in  his  own  lifetime -- the  end of the
fossil-fuel age, triggered by the harnessing of vacuum energy. They found it
hard to imagine  the smog-choked cities of the twentieth  century,  and  the
waste, greed and appalling environmental disasters of the Oil Age.
     'Don't blame  me,' said Poole, fighting back gamely after one  round of
criticism. 'Anyway, see what a mess the twenty-first century made.'
     There was a chorus of 'What do you mean?'s around the table.
     'Well, as soon as the so-called Age  of Infinite  Power  got under way,
and  everyone had thousands of kilowatts of cheap, clean energy to play with
-- you know what happened!'
     'Oh, you mean the Thermal Crisis. But that was fixed.'
     'Eventually -- after you'd covered  half the Earth with  reflectors  to
bounce the  Sun's  heat  back into space.  Otherwise  it would have  been as
parboiled as Venus by now.'
     The crew's knowledge of Third Millennium  history  was  so surprisingly
limited that Poole --  thanks to the intensive education he had received  in
Star City -- could often amaze  them with details  of events centuries after
his own time. However, he was flattered to discover how well-acquainted they
were with Discovery's  log, it had become  one of the classic records of the
Space Age. They looked on it as he might have regarded  a Viking saga; often
he had to remind himself that he  was midway in time between Goliath and the
first ships to cross the western ocean...
     'On your Day 86,' Stars reminded him, at dinner  on the fifth  evening,
'you  passed within two  thousand kay  of asteroid 7794 --  and shot a probe
into it. Do you remember?"
     'Of course  I do,' Poole  answered rather brusquely 'To me, it happened
less than a year ago'
     'Um, sorry. Well, tomorrow we'll be even closer to 13,445. Like to have
a look?' With autoguidance and freeze-frame,  we should have a window all of
ten milliseconds wide.'
     A hundredth  of  a  second! That  few minutes  in Discovery  had seemed
hectic enough, but now everything would happen fifty times faster.
     'How large is it?' Poole asked.
     'Thirty  by  twenty  by  fifteen metres,'  Stars replied. 'Looks like a
battered brick.'
     'Sorry  we don't  have a slug to fire at it,' said Props. 'Did you ever
wonder if 7794 would hit back?'
     'Never occurred to us. But it did give the astronomers a lot  of useful
information,  so  it  was worth the risk... Anyway, a  hundredth of a second
hardly seems worth the bother. Thanks all the same.'
     'I understand. When you've seen one asteroid, you've seen them --'
     'Not true, Chips. When I was on Eros --'
     'As you've told  us at least a dozen times --, Poole's  mind  tuned out
the discussion, so that it was a  background of meaningless  noise. He was a
thousand years  in the past,  recalling  the only  excitement of Discovery's
mission before the final disaster. Though he and Bowman were perfectly aware
that  7794 was  merely  a lifeless,  airless chunk  of  rock, that knowledge
scarcely affected  their  feelings. It was the  only solid matter they would
meet this side of Jupiter, and they  had stared at  it  with the emotions of
sailors on a long sea voyage, skirting a coast on which they could not land.
     It was turning slowly end over  end, and  there were mottled patches of
light  and  shade distributed  at random  over  its  surface.  Sometimes  it
sparkled like a distant  window,  as planes or  outcroppings  of crystalline
material flashed in the Sun...
     He  remembered, also, the  mounting tension as  they  waited  to see if
their aim had been accurate. It was not easy to hit such a small target, two
thousand kilometres away, moving at a relative velocity of twenty kilometres
a second.
     Then, against  the  darkened portion of the asteroid, there had  been a
sudden, dazzling explosion of light.  The  tiny  slug -- pure Uranium 238 --
had impacted at meteoric speed:  in a fraction of a second,  all its kinetic
energy  had  been transformed  into  heat. A puff  of  incandescent  gas had
erupted  briefly  into  space, and  Discovery's cameras were  recording  the
rapidly  fading  spectral lines,  looking  for  the  tell-tale signatures of
glowing atoms. A few hours later, back on Earth, the astronomers learned for
the  first time the  composition of an asteroid's crust. There were no major
surprises, but several bottles of champagne changed hands.
     Captain  Chandler  himself  took  little  part  in the very  democratic
discussions  around his semi-circular table:  he seemed  content to  let his
crew relax and express their feelings in this informal atmosphere. There was
only one unspoken rule: no  serious business at mealtimes. If there were any
technical or operational problems, they had to be dealt with elsewhere.
     Poole had been  surprised --  and a  little shocked -- to discover that
the crew's knowledge of Goliath's systems was very superficial. Often he had
asked questions which should have been easily  answered, only to be referred
to the ship's own memory banks. After a while, however, he realized that the
sort  of  in-depth  training  he had  received  in  his  days was no  longer
possible: far too many complex systems were involved for any man or  woman's
mind  to  master. The  various specialists merely had  to  know  what  their
equipment  did, not how.  Reliability depended on  redundancy  and automatic
checking, and human intervention was much more likely to do harm than good.
     Fortunately none was required on this voyage: it had been as uneventful
as any skipper  could have hoped, when the new  sun of Lucifer dominated the
sky ahead.

        III THE WORLDS OF GALILEO

     (Extract, text only, Tourist's Guide to Outer Solar System, v 219.3)

     Even today, the giant  satellites  of what was  once Jupiter present us
with  major mysteries. Why are four  worlds, orbiting  the same primary  and
very similar in size, so different in most other respects?
     Only in the  case of Io, the innermost satellite, is there a convincing
explanation.  It  is  so  close  to  Jupiter  that  the  gravitational tides
constantly kneading its interior generate  colossal quantities of heat -- so
much, indeed, that Io's surface is semi-molten. It is the  most volcanically
active  world in the Solar System; maps of Io have a half-life of only a few
decades.
     Though  no  permanent human bases have ever been established in such an
unstable  environment,  there  have  been  numerous  landings  and there  is
continuous  robot monitoring. (For  the  tragic fate of the 2571 Expedition,
see Beagle 5.)
     Europa,  second  in  distance  from Jupiter,  was  originally  entirely
covered in ice, and showed few surface features except a complicated network
of cracks. The tidal forces which  dominate Io were much less powerful here,
but produced enough heat to give Europa a global ocean  of liquid  water, in
which many strange life-forms have evolved.
     In 2010 the Chinese ship Tsien touched down on Europa on one of the few
outcrops of solid rock protruding through the  crust of ice. In doing  so it
disturbed a creature of the Europan  abyss and was destroyed (see Spacecraft
Tsien, Galaxy, Universe).
     Since  the  conversion  of Jupiter into  the mini-sun Lucifer  in 2061,
virtually all of Europa's ice-cover has melted, and extensive  vulcanism has
created several small islands.
     As is well-known, there have  been  no landings on Europa for almost  a
thousand years, but the satellite is under continuous surveillance.
     Ganymede, largest moon in  the Solar System (diameter 5260 kilometres),
has also  been affected  by  the creation of a new sun, and  its  equatorial
regions are warm  enough to sustain  terrestrial life-forms, though  it does
not yet  have a  breathable atmosphere. Most  of its population is  actively
engaged  in  terraforming and  scientific research; the main  settlement  is
Anubis (pop 41,000), near the South Pole.
     Callisto is again  wholly different.  Its entire surface  is covered by
impact craters of all sizes, so numerous that they  overlap. The bombardment
must have  continued  for millions  of years,  for  the  newer craters  have
completely obliterated  the  earlier  ones.  There  is no permanent  base on
Callisto, but several automatic stations have been established there.

     17 Ganymede

     It was unusual for Frank Poole to oversleep, but he had been kept awake
by strange dreams.  Past and present were inextricably  mixed;  sometimes he
was on Discovery, sometimes in the  Africa  Tower -- and sometimes he  was a
boy again, among friends he had thought long-forgotten.
     Where am I? he asked  himself as he struggled up to consciousness, like
a swimmer trying to get back to  the surface. There was a small window  just
above his bed, covered by a curtain not thick enough to completely block the
light from outside. There had been a time, around the mid-twentieth century,
when  aircraft  had  been  slow  enough  to  feature  First  Class  sleeping
accommodation:  Poole had  never sampled this  nostalgic luxury,  which some
tourist organizations  had  still  advertised in  his own day, but he  could
easily imagine that he was doing so now.
     He drew  the  curtain and looked out. No, he  had not  awakened  in the
skies of  Earth,  though the landscape unrolling  below was  not unlike  the
Antarctic. But the  South  Pole  had never boasted two  suns, both rising at
once as Goliath swept towards them.
     The  ship  was  orbiting  less  than a  hundred  kilometres above  what
appeared to be an immense ploughed field, lightly dusted  with snow. But the
ploughman must have  been drunk  -- or  the  guidance system  must have gone
crazy -- for  the furrows meandered  in every direction,  sometimes  cutting
across  each other or turning back on themselves. Here and there the terrain
was dotted with faint circles --ghost craters from meteor impacts aeons ago.
     So  this  is  Ganymede,  Poole  wondered  drowsily. Mankind's  furthest
outpost from home! Why should any sensible person want to  live  here? Well,
I've  often  thought  that  when I've  flown  over Greenland  or Iceland  in
winter-time...
     There was  a knock  on the door, a 'Mind  if I come  in?', and  Captain
Chandler did so without waiting for a reply.
     'Thought  we'd let you sleep until we landed  -- that end-of-trip party
did last longer than I'd intended, but  I couldn't risk  a mutiny by cutting
it short.'
     Poole laughed.
     'Has there ever been a mutiny in space?'
     'Oh, quite a  few but  not in my time. Now we've mentioned the subject,
you might say that Hal started the tradition... sorry -- perhaps I shouldn't
-- look -- there's Ganymede City!'
     Coming  up over  the  horizon was  what  appeared to  be  a criss-cross
pattern of streets and avenues, intersecting almost at right-angles but with
the  slight  irregularity  typical  of  any  settlement  that  had  grown by
accretion,  without central planning.  It was bisected  by a broad river  --
Poole recalled that the equatorial  regions of Ganymede were now w