Frankly Frank and the Unidentified Flying Blob by Damon Burnard
Frank and Watson want to see the stars close up. Luckily Tina's Everything Shop sells, well, everything, and one length of string, two buttons, a twig, a bent paper clip and a gooey mint later, a telescope is theirs. But instead of the stars, all Frank and Watson can see is a mighty unidentified flying blob, and it's headed straight at them...!