- review stars of Big Dipper and ensure all are entered correctly
Astronomy Without a Telescope
- Cambrian (Wikipedia)
The Cambrian Period ( /ˈkæmbri.ən, ˈkeɪm-/ KAM-bree-ən, KAYM-; sometimes symbolized Ꞓ) is the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period 485.4 mya. Its subdivisions, and its base, are somewhat in flux. The period was established as “Cambrian series” by Adam Sedgwick, who named it after Cambria, the Latin name for ‘Cymru’ (Wales), where Britain’s Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large “Transition Series”, although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of lagerstätte sedimentary deposits, sites of exceptional preservation where “soft” parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods.
- Merak (stars.astro.illinois.edu)
MERAK (Beta Ursae Majoris). High in the sky in northern spring evenings, just climbing above the northern horizon in southern hemisphere autumn, the Big Dipper – the “plough” in England – is among the most recognized and recognizable of figures, one of the first learned in a quest to know the constellations.
- Merak (star) (Wikipedia)
Merak /ˈmɪəræk/, also called Beta Ursae Majoris (β Ursae Majoris, abbreviated Beta UMa, β UMa), is a star in the northern constellation of Ursa Major.
