As Earth orbits the Sun, it completes one rotation every 23.9 hours. It takes 365.25 days to complete one trip around the Sun. That extra quarter of a day presents a challenge to our calendar system, which counts one year as 365 days.
How NASA Studies Fires in a Changing World. From forest floor to space, NASA scientists and collaborators are advancing tools and methods to predict, remotely detect, and ultimately mitigate wildfires.
3 天之前 · Earth, third planet from the Sun and the fifth largest planet in the solar system in terms of size and mass. Its single most outstanding feature is that its near-surface environments are the only places in the universe known to harbor life. Learn more about development and composition of Earth in this article.