The dust kicked up from the crater would have filled the atmosphere and spread throughout the world, blocking out sunlight for several years before finally settling in a layer over the entire Earth. Plants would have died due to lack of photosynthesis. Plant eaters would have trouble finding food, especially the large plant-eating dinosaurs. The cold-blooded dinosaurs would also have had difficulty with the reduced temperatures. Only those species who could survive on relatively little food or on stored nuts and berries or in the ocean could have survived.
Extrasolar planets are planets outside our own solar system.
The planets are too distant to be found by direct observation, so other methods must be used. The major method for finding these planets is called astrometry. By measuring the amount of motion of the star, the number of planets and their masses may be determined. Another method to find extrasolar planets is occultation - the slight dimming of light from a star as a planet passes our line of sight. The planets found so far have all been jovian type planets.