Multiple choice The rigid outer layer of Earth that consists of the crust and upper mantle is called? lithosphere asthenosphere outer core transition zone Reveal answer Fill a bubble to check yourself A Correct answer Explanation The lithosphere is the cool, rigid outermost shell of Earth, encompassing the crust and the uppermost portion of the mantle. Below it lies the asthenosphere, which is a hotter, weaker, and more ductile layer of the mantle.