sci fi....

may have posted about this one before a few years ago...

it was in a reader's digest, i'm almost positive. was about a space probe that went to jupiter (i think) where it entered the atmosphere and descended below to find a water planet. it entered the water and scientists were amazed to find organic matter in the water. as it went further (there was also a camara), they saw pictures of an obviously intelligent species living there. sadly, as it went further, they discovered that the creatures, which looked like whales, had been completely wiped out by a comet striking the planet (spelled badly: shoemacher levy-9). it was an awesome discovery but also horrible due to the tragedy?

i must have read this in '95? but i'm fairly certain it was published far before that as they were my dad's and had been around for awhile.

any clues? an amazing story....

edited to add that the comet that hit jupiter was Shoemaker-Levy 9 in '94. and since i read it at my dad's house, it had to be between then and '97.
It might be this one?
http://en.wikipedia.org/wiki/Jupiter_%28novel%29

I googled "jupiter" & "whales" and this came up. The comet impact seems to be in it too...although, on second look I see that it was published in 2000.
Can it be that you read it a bit later than you seem to remember? If not,then this is probably not it.
read the info on it but it's not it. the comet hit jupiter in '94 (thank you google) so it would be between then and '96 for sure. this was also more about the actual probe than the characters, or so i remember.
i just did a quick, but extensive search for it, but no avail. sad times. i know its real lol
I missed the Readers Digest remark. Arthur c Clarke did write a novella about Jupiter in 1971 but that appeared in Playboy, which i am sure the OP would not confuse with RD.
Building on the other commenter's observation, another possibility is the following anthology by Reader's Digest (from 1977). Again, anything look familiar?

Reader’s Digest Science Fiction Top-Picks ed. Judith Hatch (Reader’s Digest Services 0-88300-328-7, 1977, 96pp, tp); Textbook, all stories abridged.

4 · Out at First Space · Laurence Swinburne · ss *
12 · City of the Gods [abridged from “The Place of the Gods”, The Saturday Evening Post Jul 31 ’37] · Stephen Vincent Benét · ss *
20 · Nobody There [“Neuteronomy”] · Eve Merriam · pm Out Loud, Atheneum, 1970
22 · Blood Brother · Thomas N. Scortia · ss Future Kin, ed. Roger Elwood, Garden City, NY: Doubleday, 1974; abridged
33 · The Weight Watcher [abridged from “The Iron Chancellor”, Galaxy May ’58] · Robert Silverberg · ss *
41 · They Got There First · Irene & Laurence Swinburne · ar *
46 · Hill of the Flashing Light · Paul S. Newman · ss *
55 · Planet of Changes · Agnes McCarthy · ss *
64 · Space: 1999—The Infernal Machine · Anthony Terpiloff & Elizabeth Barrows · pl London: Futura, 1975; abridged
76 · The Total Eclipse · Nina B. Link & Angus D. Wright · ss *
85 · Danger—Human! · Gordon R. Dickson · ss Astounding Dec ’57; abridged
I suspect that the book is older than the 90s as SF would not portray Jupiter as a water planet after the missions of the 1970s. The comet strike in your novel might not have been Shoemaker-Levy 9 but a fictional one to explain the deaths of the creatures.
Could it perhaps have been either "Symphony for Skyfall" or "Unfinished Symphony", by Rick Cook and Peter L. Manly?

Unfortunately, the Internet doesn't give me a lot to back up my own rather out of date memories of the stories, but they definitely involved whale-like creatures (who floated in the atmosphere of jupiter). The first story featured the Shoemaker-Levy impact, and the second story featured the atmospheric probe from the Galileo.

However, the isfdb tells me here ( http://www.isfdb.org/cgi-bin/pe.cgi?30904 ) that both were only published in Analog, so maybe not.

Other things I can remember about the stories... They are mostly told from the perspective of one of the whale creatures. The whale creatures communicate via electrical impulses and have a "music" that is very important to their culture. In the second story, the creatures encounter the atmospheric probe, and use their electrical control to "sing" a message that is detected by human researchers.

It doesn't fit in a lot of details, but it does in others. Maybe?
I created an account on LiveJournal just to suggest the very same novel that the first poster November_Vine mentioned. The wikipedia entry doesn't flesh out the book in full because your description sounds JUST like Bova's Jupiter.