- Achernar (stars.astro.illinois.edu)
ACHERNAR (Alpha Eridani). There are 22 classical “first magnitude” stars in the sky. Of these, nine are so bright that in modern times they had to be placed into even brighter categories, seven into “zeroth” magnitude (the brightest of which is Alpha Centauri) and two (Canopus and Sirius) into the exclusive “minus-first magnitude” group. Of these nine, Achernar ranks last, right behind Procyon in Canis Minor and just beating out Hadar in southern Centaurus.
- Mesoproterozoic (Wikipedia)
The Mesoproterozoic Era is a geologic era that occurred from 1,600 to 1,000 million years ago. The Mesoproterozoic was the first era of Earth’s history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), but little is known about them. The continental masses of the Mesoproterozoic were more or less the same ones that exist today, although their arrangement on the Earth’s surface was different.