Tuesday, March 19, 2024

Archive for March 9, 2010

Earthsky Tonight—March 10: Is Sirius the most

Earthsky Tonight—March 10: Is Sirius the most luminous star in the sky?

Courtesy of EarthSky A Clear Voice for Science www.EarthSky.org Look south at nightfall and early evening, and you can’t miss Sirius, the brightest star in the nighttime sky. Mia asks, “Isn’t there a brighter star in absolute magnitude which appears dimmer because of its distance?” Yes, Mia, you are right. Sirius looks extraordinarily bright in Earth’s sky because it is only 8.6 light-years away. Many stars on the sky’s dome are intrinsically more luminous than Sirius, but ... Full Story

Earthsky Tonight—March 9: Ancient eye test relied on

Earthsky Tonight—March 9: Ancient eye test relied on two stars in Big Dipper

Courtesy of EarthSky A Clear Voice for Science www.EarthSky.org Look back to “this chart”  for more about how to recognize the Big and Little Dippers on these almost-spring evenings. The ancient eye test for those wishing to join the Roman army was administered using stars in the handle of our modern-day Big Dipper. If you passed, you got a job as an archer. If you failed, you had to serve in another capacity … perhaps as a cook. It is said that sultans of the past also tested their ... Full Story