Consider an object in orbit around a star. The star suddenly shrinks in size, but does not change its mass. What happens to the object's orbit?
A) It is instantly ejected from its orbit.
B) It remains in the same orbit.
C) It settles into a smaller orbit, with similar distance from the surface as the original orbit.
D) It gradually spirals into the star.
Question 2
Which of the following best describes why the Sun emits most of its energy in the form of visible light?
A) Nuclear fusion in the Sun's core produces visible light photons.
B) The Sun's gas is on fire like flames from wood or coal, and these flames emit visible light.
C) Like all objects, the Sun emits thermal radiation with a spectrum that depends on its temperature, and the Sun's surface temperature is just right for emitting mostly visible light.
D) The visible light comes from energy level transitions as electrons in the Sun's hydrogen atoms jump between level 1 and level 2.
Large size can provide a refuge from predators. While young African elephants may be vulnerable to p
Spectral Line Motion in Binary Star Systems
Desertification and Climate Change
Hares and Lynx population change "الأرانب البرية و الوشق"
Rock cores as indicators of environmental change