[...]... threads are tied together The point at which the Moon crosses the plane of the Earth’s orbit going northward is the ascending node Going south, the Moon crosses the plane of the Earth’s orbit at the descending node A solar eclipse can occur only when the Sun is near one of the nodes as the Moon passes If the Sun stood motionless in a part of the sky away from the nodes, there would be no eclipses, and you... by the Moon twice during a single node crossing, thereby creating two partial eclipses within a month of one another The closer the Sun is to the node when the Moon crosses, the more nearly the Moon will pass over the center of the Sun s face In fact, if the Sun is within about 10 degrees of the node at the time of the Moon’s crossing, a central eclipse will occur somewhere on Earth Depending on the. .. roughly, there is a “danger period,” called an eclipse season, when the Sun is crossing the region of the nodes and an eclipse is possible Eclipse limits Sun Moon 5° tilt Earth Plan e of Moo n’s o Ecliptic (Plane of Ear rbit Node th’s orbit) The paths of the Sun and Moon illustrate why eclipses occur only when the Sun is near the intersection (node) where the Moon crosses the ecliptic The plane of the Moon’s... happen When the Sun nears a node, there is the “danger” that the Moon will be coming and—crash! No The Moon is 400 times closer to the Earth than the Sun, so the worst the best—that can happen is that the Moon will pass harmlessly but stunningly right in front of the Sun The Sun s apparent pathway in the sky is called the ecliptic because it is only when the Moon is crossing the ecliptic that eclipses. .. The corona, the most striking and unexpected of all the features of a total eclipse, is emerging At one edge of the Moon the brilliant solar crescent remains Together they appear as a celestial diamond ring Suddenly, the ends of the bare sliver of the Sun break into individual points of intense white light—Baily’s beads the last rays of sunlight passing through the deepest lunar valleys The beads flicker,... there is just one left It glows for a moment, then fades as if it were sucked into an abyss Totality Where the Sun once stood, there is a black disk in the sky, outlined by the soft pearly white glow of the corona, about the brightness of a full moon Small but vibrant reddish features stand at the eastern rim of the Moon’s disk, contrasting vividly with the white of the corona and the black where the. .. small to occult the Sun completely In the midst of such an eclipse, a circle of brilliant sunlight surrounds the Moon, giving the event a ringlike appearance; hence the name annular eclipse (from the Latin annulus, meaning ring) Because the angular diameter of the Moon is smaller than the angular diameter of the Sun on the average, annular eclipses are more frequent than total eclipses But the Moon does... in front of the Sun It is in orbit around the Earth It catches up with and passes the Sun s position in the sky about once a month (a period of time derived from this circuit of the Moon) The actual time for the Moon to complete this cycle is 29.53 days, and it is called a synodic month, after the Greek synodos, “meeting” the meeting of the Sun and the Moon Because the Moon gives off no light of its... opera house and saying that you have seen the opera; in both cases, you have missed the main event Jay M Pasachoff (1983) First contact A tiny nick appears on the western side of the Sun. 1 The eye detects no difference in the amount of sunlight Nothing but that nick portends anything out of the ordinary But as the nick becomes a gouge in the face of the Sun, a sense of anticipation begins This will be no... shadow of the Moon silently slips past you and rushes off toward the east It is then you ask, “When is the next one?”2 The Experience of Totality 5 Notes and References Epigraph: Donald H Menzel and Jay M Pasachoff: A Field Guide to the Stars and Planets, 2nd edition (Boston: Houghton Mifflin, 1983), p 409 [1] In sky observations, the western side of the Sun or Moon refers to the edge of the Sun or . sensitive to provide proof that the corona seen around the Moon at eclipses was, in fact, part of the Sun. In the middle of the book, the authors describe the science of the Sun and how energy gets. totality, the western sky is now darker than the east, regardless of where the Sun is in the sky. The shadow of the Moon is approaching. Even if you have never seen a total eclipse of the Sun. the darkened Sun. The corona, the most striking and unexpected of all the features of a total eclipse, is emerging. At one edge of the Moon the brilliant solar crescent remains. Together they