All of the planets, dwarf planets, asteroids, meteorites, and comets orbit the Sun. The planets follow a path around the Sun called an ellipse, which is an oval-shaped orbit. In addition to these objects, moons also orbit planets, moving around them as the planets travel through space.
Figure solar system bodies where relative sizes are in scale. Image credit: Dave Jarvis
Earth’s distance from the Sun changes slightly throughout the year due to its elliptical orbit. The day when Earth is closest to the Sun is called Perihelion Day. This usually happens in January. In contrast, Aphelion Day occurs in July, when Earth is farthest from the Sun. These shifts may seem small, but they’re a natural part of our planet’s yearly journey around the Sun.
Earth’s tilt is 23.5 degrees. This causes our planet’s seasons. The Northern Hemisphere has the most sunlight during the solstice in June. Another solstice happens in December. During this time, the Northern Hemisphere gets the least sunlight. However, it is the opposite for the Southern Hemisphere.
The average distance between Earth and Sun is 1 Astronomical Unit (about 93 million miles). We are at the correct distance for the Sun’s energy to provide the right amount of heat and light for life. This means that it resides in the Habitable Zone. It takes about 8.3 minutes for sunlight to reach Earth. Light travels at 186,000 miles per second.
Helio-physics is the science of studying the Sun and its influence throughout the Solar System. To learn more about the Sun and our solar system, please visit the WVU Planetarium in White Hall. Free public shows are set for every other Friday evening. There are also other cool things on display like a tire flown on a mission by the Space Shuttle Columbia.
2025 WVU Country Roads Program Graduating Class. Image credit: Kayla Richard / WVU Country Roads Program
Congratulations Country Roads graduates !!!