USAAAO 2018, I кръг — Задача 10
USAAAO National Astronomy Olympiad First Round 02/12/2018-02/16/2018 Time Limit: 75 Minutes · 12 февруари 2018 г. · 1 т.
Внимание: Бележка към темата
The solutions document provides answer letters for all 30 problems and brief explanations for some problems.
Условие
When seen from Earth, what is Venus' phase when it is at greatest elongation?
A. New
B. Crescent
C. Quarter
D. Gibbous
E. Full
Решение
Answer: C
At greatest elongation the Sun-Venus-Earth system forms a right angle, therefore Venus will be seen from Earth as half illuminated which is a quarter phase.
Оригинал в Архива: usaaao-first-round-exam-2018.pdf · официални решения: usaaao_first_round_2018.pdf