1.  Asimov supports his thesis by detailing for readers the wonders of the solar system and the universe.  He describes interesting details about the stars and reveals that all the discoveries are relatively recent.  This approach brings the reader to the conclusion that the beauty of the night sky can be enriched by the knowledge of science and that one misses a great deal when one claims knowledge destroys the beauty of the night sky.  A knowledgeable view can enjoy much, much more. 

2.  
Planet	are worlds
have atmospheres
are red-hot liquid or dead worlds	
stars	actually suns
some huge, other smaller and cooler
some compact, most dense are black holes
some pulsate, some expand, some explode
night sky has 2500, there are 300 billion in our galaxy	
galaxy	Milky Way - pinwheel-shaped
huge, 100 thousand light years across, rotates every 200 million years - lots more galaxies out there - maybe 100 billion in total
centers of galaxies are violent, devour stars
some centers very bright due to violence, can be seen 10 billion light years away 
galaxies are moving away from each other.	
Universe	was once a tiny sphere that exploded 
expanding ever since
not know if it will expand forever - may start contracting
if alternately expands and contracts it will seem like the universe is breathing.  	

3.  Asimov frames his rhetorical questions in such a way that the reader is compelled to answer yes to them.  This technique adds to the persuasiveness of the essay. 

4.  Coherence - Outlining an essay

The outline of this essay demonstrates how each part is connected to the other which build coherence.  The essay is “framed” by the poem at the beginning and the end.

Para. 1 - Walt Whitman Poem
Para. 2 - points out many people would agree with Whitman
Para. 3 - points out problems with people who agree with Whitman
Para. 4 - says Whitman is wrong but it’s not his fault. 
Para. 5 - agrees that the night sky is beautiful (scene in poem) and says he also has gone out to just enjoy its beauty. 	
Para. 6 states he knows that the beauty he sees isn’t all the beauty there is to see (thesis) which he proceeds to demonstrate by examples.
Paras. 7-16 list the beauty he knows is out there but can’t be seen by the naked eye; this makes it more interesting and descriptive than the naked eye’s “twinkling points of light”.  Whitman organizes the information from smaller (planets) to largest (the universe)- logical pattern.
Para. 17 - returns to Whitman - all this new information discovered after Whitman’s death, so it isn’t his fault he didn’t know what he was talking about in the poem. 
Para. 18 - clincher- only science provides us with the fascinating knowledge that Asimov shares with us - more beauty is yet to come through science.

He builds coherence as well through use of effective transitions, which link ideas from previous paragraph and extend forward into the next paragraph.