Boundary, by Eric Flint and Ryk E. Spoor

I'm not entirely certain that I can do much better with this review than the book blurb does. Gotta find out how to become a professional blurbist. Flint's been around a while, but Spoor is new to me.

This was merely some competent entertainment, basically. The story starts when an archaeologist finds some anomalous fossils in the KT boundary. A group of raptors appears to have been killed by an alien from outer space, and somehow their remains were preserved in the fossil record. Of course, the archaeologist in question, Helen Sutter, is subjected to ridicule for even suggesting that aliens might have visited Earth in the distant past, but her career survives despite it all.

Later on in the story, though, an exploratory mission to Phobos, one of Mars' moons, discovers a long abandoned alien base. In the alien base...you guessed it! The scientists find mummified remains exactly like the fossil remains discovered by Dr. Sutter. The excitement created by this discovery motivates the U S government to put together a massive manned expedition to Phobos to exploit any alien technology to be found there.

The whole story reminds me a bit of some early Heinlein, like Have Space Suit, Will Travel, Rocket Ship Galileo, Podkayne of Mars, and so forth. Nothing terribly earthshaking, in this day and age, but enough to provide a few hours of amusement. There is, however, some interesting high tech wizardry with nano-swarm imaging and nuclear space drives.