The sun is a star at the center of the solar system with planets that revolve around it. The sun’s gravity holds all these planets in their orbits. It is an ever-changing ball that is made up mostly of hydrogen and helium. The sun’s temperature at its core is 27 million degrees Fahrenheit (°F) or 15 million degrees Celsius (°C). At the sun’s surface, the photosphere, the temperature is about 10,000 °F (5,500 °C). On the surface, there are sunspots which are darker areas with a strong magnetic field. These areas are cooler than areas surrounding them. The sun’s energy creates “solar wind” that can reach speeds up to 400 mph. • The sun rotates approximately once every 26 days. • It is 4.5 billion years old. • Light travels from the sun to Earth in 8 minutes and 19 seconds. • The sun is so large that 1 million Earths could fit inside of it. To figure out what your weight on the sun would be, multiply your weight by 27.95.
Mercury’s average distance from the sun is 57,909,227 km (35,983,125 miles). Mercury is one of the four terrestrial planets of our solar system. Terrestrial planets are mainly composed of rock and have solid surfaces. Venus, Earth and Mars are the other terrestrial planets. Mercury is slightly larger than Earth’s moon, and has a surface similar to the moon as well. The extremely thin atmosphere on Mercury has resulted in impact craters from collisions with meteoroids and comets. The atmosphere experiences extreme temperatures on the planet ranging from 800 °F (427 °C) to a low of -290 °F (-179 °C). • Mercury’s orbit around the sun takes only 88 Earth days, but its rotation is slow, lasting almost 176 Earth days. That makes its day twice as long as its year. • Faster than the other planets, Mercury travels at 50 km (31 miles) per second. • Based on radar observations, astronomers believe Mercury may have water ice deep in the craters at the north and south poles. To figure out what your weight on Mercury would be, take your weight and multiply it by 0.38. To calculate your age on Mercury, divide your age in Earth years by 0.241.
Venus’ average distance from the sun is 108,209,475 km (67,238,251 miles). The shiny object that we refer to as “morning star” or “evening star” is actually the planet Venus. The light we see is from the clouds reflecting the sunlight, but under the clouds Venus is a place of intense heat and volcanic activity. The atmosphere under the clouds consists mainly of carbon dioxide which traps the heat. This “greenhouse effect” can cause temperatures to be higher than 880 °F (471°C). Venus is often referred to as Earth’s sister planet due to its similar size and mass and gravitational pull. • Some Russian spacecraft that landed on Venus quickly melted from the heat and were crushed by the pressure, but they did manage to send back a few images before being destroyed. • Venus rotates clockwise quite slowly. Most of the planets in our solar system rotate counter-clockwise. • Lightning bursts in Venus’s atmosphere have been confirmed by the European Venus Explorer in 2007. This lightning is associated with clouds of sulfuric acid unlike the lightning on Earth, Jupiter and Saturn which is associated with water clouds. To figure out what your weight on Venus would be, take your weight and multiply it by 0.91. To calculate your age on Venus, divide your age in Earth years by 0.615.
reverse
Reverse Side Text
Each solar body marker sign has factoid information printed on the reverse side on the same materials as the front sides. View all reverse side factoid texts.