either of two periods of partial darkness, after sunset or before sunrise, when the center of the sun is more than 6° but less than 18° below the horizon.
- Astronomical unit
a unit of length, equal to the mean distance of the earth from the sun: approximately 93 million miles (150 million km). Abbreviation: AU. Historical Examples That was one astronomical unit, equal to about ninety-three million miles, the distance from Earth to the sun. Rip Foster in Ride the Gray Planet Harold Leland Goodwin In […]
- Astronomical year
(def 4b). Historical Examples Do all that you can to teach the signs of the zodiac, the days of the seasons, and all the doings of the astronomical year. Winter Dallas Lore Sharp His astronomer, by name Sosigenes, did his best, but assumed the astronomical year to be 11 min. More Science From an Easy […]
of, relating to, or connected with . extremely large; exceedingly great; enormous: It takes an astronomical amount of money to build a car factory. Contemporary Examples The Instagram deal coincided with astronomically high hopes for the Facebook IPO. How Joining Facebook Is Hurting Instagram Alex Klein August 27, 2012 If you had such an astronomically […]
the science that deals with the material universe beyond the earth’s atmosphere. Contemporary Examples “Occult” literally means “hidden from view,” which is why we use it both in astronomy and to refer to secret knowledge. Chariklo, a Minor Planet Nicknamed a “Centaur,” Discovered to Have Rings Matthew R. Francis April 5, 2014 After To Die […]