dont know the book... "human spaceship detects alien vessel..."

[mauhumor]

Hello, I am trying to find a book, i never read it myself, my father told me the story but he doesnt remember the "book" name, its something like this:


It contains two stories with the same background:


A human spaceship is 'sailing' into an unexplored region and detects an alien spaceship, the two ships began to approche each other.
The ship have no means to communicate with other human ship or planet and humanity had never found an alien species before.

There are two endings.

One:

In one story they decide to destroy the alien ship by self-destructing when the two ships approche.
They belive that there are a chance the aliens to be hostile, and by tracing the human ship route the aliens could find earth, destroy mankind, etc. They could not risk that possibility.

Two:

In the other story, the crew decide to meet peacefully meet the aliens.

Im trying to find it for years! With only that information even google could not help me out.
:confused:

[Lowlander]

That plot reminds me a lot of First Contact by Murray Leinster. However First Contact is not a novel but a novelet written in 1945. It's a classic SF story and has been reprinted many times since.

[uncwilult02]

Maybe The Mote In God's Eye by Larry Niven? In that novel humans actually trace the course of destroyed light-sail vessel back to its origin, and have a tension filled first encounter with aliens.

[mauhumor]

Thanks! I would never find it out alone!

Already found in an onlilne used book store both "First Contact by Murray Leinster" and "The Mote In God's Eye by Larry Niven", both in portugues, brazilian print.

Thanks again!