Science Seasonal changes in color or contrast on mars were once thought to indicate the presence of vegetation or water. Are there still seasonal changes, and if so, why?
Science, Solar System If our solar system is composed of the remains of stars that used up their hydrogen and went supernova, where did our sun get the hydrogen it began with?
Science, Solar System How is the temperature of the Sun’s surface measured through its much hotter atmosphere, the corona?
Science, Solar System I saw a program that showed the Moon revolving around Earth, causing the oceans to swell on both sides of the planet. Shouldn’t the ocean opposite the Moon be shallower than the side facing it?
Science, Stars How do we know what stars are behind dark nebulae (if they absorb the light from background stars)?
Science What are the motions of stars relative to each other in a globular or open cluster? Does the cluster move as a unit over time?
