The sun is gonna blow up. Too bad, eh? That's our future, some time in the 35th century. You might think that the story would centre around trying to stop it, but that is beyond the capability of even that fictional technology; the real story is about those who survive on other planets. Arthur C. Clarke is fond of staying within the boundaries of known physics, and it shows here - there are no unexplained drives powering ships at warp speeds into alien galaxies. Instead, he crafts a world where, in an attempt to save at the earth's life itself if not the actual beings on it, intricate ships containing the unborn versions of entire worlds are sent off to colonize other planets. At sublight speeds this takes centuries of course, but the travelers don't mind.
One of the few planets successfully colonized in this manner is Thalassa, an ocean planet with a temperate climate. Though the new inhabitants of this planet built a large antenna communications antenna to report their existence to earth, it was destroyed by a volcanic eruption. For this reason, they are surprised by the arrival to their planet of a large ship from earth, with a million of earths last people stowed in hibernation.
The Magellan as the ship is named, fortunately isn't looking for sanctuary on Thallassa, the small continent having almost reached optimal population. The crew-members of the Magellan are instead looking for ice to replenish the shield that protects them from collision with particles during their high speed trek through the galaxy.
There are many plots running through this book; almost too many. The one that I thought was the most important, the potential of some sort of intelligent life existing on Thalassa, turned out not to be developed at all the way I thought it might be. Perhaps that one was being left for the sequel... But in any case, throughout there is love, death, talk of mutiny, deep psychology, and lots more. (I noticed in particular a few references to excess of information which would be particularly apt in describing the internet, even though this book first published in 1986).
Though knowing something about the starships namesake would probably be helpful, it isn't important (I don't, after all...). I looked around a bit and found that, besides being the name of a Venusian probe, it's the name of the explorer who first sailed around the world. There are also references to events that happened either in real life or in some classical book about the sea; I'm too uncultured to even know what he's referring to, but I anticipate someone will mail me soon and help.
Lets wind this up. If you like sci-fi and have progressed to the point can tell the difference between a hack Star Trek paperback the intelligence of something like "The Andromeda Strain", then you'll like this book. If you think the writing in Reader's Digest is fresh and new, you probably won't.