2D Solar Eclipse: Umbra & Penumbra Cone Geometry

This is the side-view companion to the 3D Solar Eclipse simulator: the same Sun-Moon-Earth alignment, rebuilt as a flat schematic that draws the actual umbra and penumbra cones to scale from real Sun/Moon radii and distances. Moving the Moon along its elliptical orbit changes whether the umbra's tip even reaches the ground — push it far enough toward apogee and the cone falls short, flipping the eclipse to annular. The second control is the shadow-axis offset: because the Moon's orbit is tilted about 5.1° from the ecliptic, most new moons miss Earth's disk entirely, and only a narrow band of offsets near zero produces a real eclipse — inside the umbra it's total or annular, in the wider penumbra it's merely partial, and outside both there is no eclipse at all. Live readouts compute magnitude, umbra ground radius, and how long totality would last at that offset from the umbra's real ~0.61 km/s ground speed.