Expert: Tom Whiting - 1/6/2005

Question
Hi,

I am doing research for a sci-fi novel I am writing. I was hoping you could help clarify a few things for me.

As I understand it, our view of our own Milky Way is relatively unhindered except for the galactic core.  The dust in the region is to blame for our obscured view.  Do scientists ever forsee, short of someone going out there, peering through this dust?  I know that we can "see" the galactic core area, using non-visible light, and maybe eventually by gravitational waves, but how much information are we missing by all that dust being in the way?  I am assuming that this dust is also obstructing our view of the other side of the Milky Way galaxy, and everything else in that portion of the sky as well.

Secondly, relating to the observation of planets surrounding stars.  Is it only a matter of our telescopes not being large enough that we can't see them?  Or is the host star always going to get in the way and blind us?  I've read that most planets found are zeroed in on by observing the star wobble or other effects.  Say, for example, that a civilization about 20,000 light years distant lived upon an earth-like planet.  Short of direct contact, is there really any way someone could "stumble upon them?"  I've read that while planet earth is relatively hidden in most spectrums, we are off the chart when it comes to radio wave emmission.  Would this type of thing be seen some 20,000 light years distant?  Yes, time constraints would put a 20,000 year difference between event and seeing evidence of life, but what interests me most is how hidden are we?--or vice-versa, how hidden would someone else be?

And lastly, how reasonable is it to assume that within a 20,000 or so light year radius of our sun that maybe 30-40 earth-like, or at least planets that could be made to sustain life (i.e. such as a planet like Mars where we could establish a controlled system) be found?  Have astronomers found an earth-like planet yet?  And if not a 20,000 light year radius, then perhaps within the entire galaxy?

Sorry for the rambling questions.  Sci-fi allows me to make up a lot of things, but I try to remain fact-based, and so these are the things I think about as I fill out my story.  Thank you for any help you can provide or books you can recommend.

Answer
Hi Frank,
To answer your questions in a word, yes yes yes, yes, and
yes....the rest near the bottom are all "matter of opinion"
because the honest answer is, we don't really know as yet.
And I can also tell you are very well versed on current
astronomical happenings,  and you seem to be able to keep science fiction separate from fact.

Actually, no for the first one.....I personally don't see the
day, at least for billions of years, that the interstellar dust
blocking our view of both the center, and the other side
of our Milky Way Galaxy, will either dissipate or form into more stars.   What are we missing?  Even science cannot
know the unknown, but the most probable answer is.....
the same thing that we see on this side of our Galaxy,  OR
same thing we see when we look out at other galaxies.....
just more stars, H II regions, clusters....same thing.
And is it not probable that our core in visible light would
be pretty much the same as we see in other normal, or
barred spirals, that we see out there....I mean we ain't much
different than the Andromeda Galaxy or NGC 7331- the
one that most astronomers say is a near-mirror image of
our own Milky Way Galaxy.

On extra-solar planets,  it's a matter of resolution (separating
2 distinct points of light at a far distance), and that only
partially involves mirror size.
So it's not just mirror size,  it's also our atmosphere too....as you probably know, even on the best of nights, 0.2 arc-sec
resolution is about the maximum on Earth....so we not only need a very big mirror, we need to be out of our atmosphere too, so we can achieve the 0.00001 arc-sec resolution required
to separate a  dim reflecting planetary dot from a very bright sun (star) virtually right next to it.

We are quite hidden, as are those hypothetical "Earth-like"
extra-solar planets you speak of, except....as you state, in
the radio portion of the electromagnetic spectrum.
Planet detection is hard, painstaking work....we won't "stumble" into any small extra-solar Earths, unless they are
very very closeby, like within 10 lightyears, and that is
very highly unlikely.

OK, now you are into "matter of opinion"....30-40 Earths
within 20,000 lightyears is highly optimistic....My estimations
are like 4 or 5 "Earthlike planets" within the entire Milky
Way Galaxy at a maximum, maybe even less....in fact, we may
be unique in the Milky Way.
I base this simply on the production of "heavy elements"
Lithium to Uranium (Atomic numbers 3-92).
Our Universe is only up to 3% heavies....Our Universe is
still 97% hydrogen and helium left over from the Big Bang
only 13.7 billion years ago.   Solar System is only 4.6
billion years old...how many places in the Galaxy back then,
had a full compliment of the 3% heavies?  Not too many
in my opinion......PLUS, the total lifespan of our Universe
is determined to be nearly 100 trillion years or even more.....
13.7 Billion years is only a drop in the bucket....heck, this
"experiment" just began LAST WEEK, and we, the Solar
System, just arrived YESTERDAY.....hell, we're very lucky
to be here THIS EARLY.....in effect, we won the Big Lottery
and we're the first ones, or one of the first lifeforms, present
in the Galaxy.  All just IMHO.  But at least I can explain my
thoughts, and it all makes perfect sense to me.
Last month I just read a NASA JPL report on 12/21/04
that they have determined that the Universe is still spawning
massive star-burst galaxies out there several billion lightyears, an age of time that they originally thought was over with.  Again, backing up my thesis that our Universe
is still very, very young, and has only "just begun" on the
astronomical timescale.

Notice all the extra-solar planets they are finding, are all
Jupiter-size planets, or bigger....and what is Jupiter made
of?  All mostly hydrogen and helium (in effect, all planets are
just 'failed stars' which didn't accumulate enough mass to
trigger nuclear fusion in their cores. )  No 'heavy' elements.
All gas giants.
So forget any life on those planets.

As far as visual imaging of an extra-solar planet, there is
currently a race on between the large observatories right
now to be the first, using adaptive optics to minimize
the atmospheric turbulance of our own atmosphere.
I don't know if they will be successful or not....but probably
only the biggest of the Big Jupiters out there, and very
nearby.

In the end, I think even the few Earthlike planets out there,
we will find most have perhaps bacteria, molds, maybe even
the equivalent of sea-shell organisms...but that's a far
step from us very fortunate "super - primates"...just look
at the many evolutionary dead ends on the Earth....top of
the line (food-chain) animals, but no spacecrafts, trips to the moon, or McDonald's restaurants....Sharks, whales,  porpoises, penquins, wolves, bears, big cats, etc.
All "dead-end"lines, relative to space travel, rocketships,
computers, electricity, radio/TV, and McDonalds restaurants.  

In fact, I think we are unique in the Milky Way, and we are
here to colonize the entire galaxy, which I've read can be
done in about a million years, hopping from star to star.
Plus we have our Marching Orders from Above...did He not
say, Go Forth And Multiply?...Surely you don't think, knowing the Big Picture, surely you do not think that He was just referring to this lowly, small, insignificant 8000 mile rock
we live on, do you?   Food for Sat. evening thoughts.

Sorry for the rambling....but some of your later questions
were strictly matter of opinion, so I gave my opinion.
Hope all this helps,
Clear Skies,
Tom Whiting
Pres...ECMOG
Erie, PA

PS any further questions, please feel free to contact
me directly at bwhiting@velocity.net
and please visit our astronomy club website
for great views of my new 30 inch portable scope, at
http://www.velocity.net/~bwhiting/