SOUTHWORTH PLANETARIUM
70 Falmouth Street Portland, Maine 04103
ASTRONOMY a la CARTE NIGHT SESSIONMonday, October 22, 2018
7:00 p.m.
Have you ever wondered how the astronomers on Earth have come to know so much about the stars?! After all, nobody has actually traveled to any of them! In fact, except for a small launch of astronauts, no Earthling has even left the planet. The stars, as any astronomer would eagerly tell you, are enormously far away.
For instance, the closest star system, Alpha Centauri, is 4.3 light years away! In other words, the ultra-fast light photons leaving Alpha Centauri's three stars at this moment won't reach our verdant shores until early 2023! Mind you, light travels at 186,290 miles per second: fast enough to wrap around Earth's equator nearly eight times in that one second. That amounts to an enormous separation distance...and, ha ha, that is the closest star to the Sun!
How can astronomers know:
-that Betelgeuse is 160 million times larger in volume than the Sun?
--that red dwarf stars can live for 1 - 3 trillion years?
--that the Sun won't deplete it fuel reserves tomorrow?
--or the distances to any of these stars in the first place?
Monday night we'll go through an explanation of how astronomers know what they know about the stars!
Enrollment: $12 per person; $20.00 for two