Molly of Mars and the Alien Nebula. Molly of Mars, #2

After uncovering a dark Martian secret in their previous adventure, Molly Lennox, Pirra Lennox, and Vicky Valentine whisk off to the outer solar system for rest, relaxation, and to visit a new wonder for a school project: a beautiful alien nebula. It's the last remnant of the aliens that attacked Mars and a tether to her guilt about the death of a friend. It's Molly's wish to see it destroyed and the blackhole bomb will do it.
She just has one problem: her alien sister, Pirra. Molly can't destroy something her sister cherishes. Conflicts roil her, a betrayal by a friend churns wrath within her, and when a mystery object floating within the nebula piques her curiosity. Just when she can't take it anymore, the action starts and she finds herself trapped in space without anything to breath. For ages 10+, same reading level as Harry Potter.