Eratosthenes then measured the angle of a shadow cast by a stick at noon on the summer solstice in Alexandria, and found it made an angle of about 7.2 degrees, or about 1/50 of a complete circle. He realized that if he knew the distance from Alexandria to Syene, he could easily calculate the circumference of Earth.Eratosthenes then measured the angle of a shadow cast by a stick at noon on the summer solstice in Alexandria, and found it made an angle of about 7.2 degrees, or about 1/50 of a complete circle. He realized that if he knew the distance from Alexandria to Syene, he could easily calculate the circumference of Earth.
Who discovered our planet Earth?
Five planets have been known since ancient times — Mercury, Venus, Mars, Jupiter, and Saturn. The first new planet discovered was Uranus. It was discovered by the English astronomer Sir William Herschel in 1781 .PLANETEarthMASS1.000RADIUS1.000SURFACE GRAVITY (g)1.008 more columns
Why is the earth named Earth?
All of the planets, except for Earth, were named after Greek and Roman gods and godesses. The name Earth is an English/German name which simply means the ground. It comes from the Old English words eor(th)e and ertha.
Who discovered Sun?
Curious about the Sun, Galileo used his telescope to learn more. Not knowing that looking at our very own star would damage his eyesight, Galileo pointed his telescope towards the Sun. He discovered that the sun has sunspots, which appear to be dark in color.
Who is the last planet?
Neptune Neptune is dark, cold, and very windy. Its the last of the planets in our solar system. Its more than 30 times as far from the Sun as Earth is. Neptune is very similar to Uranus.
Who named Mars?
Mars is named for the ancient Roman god of war. The Greeks called the planet Ares (pronounced Air-EEZ). The Romans and Greeks associated the planet with war because its color resembles the color of blood.
Who named the moon?
Galileos discovery. So, why do the moons around other planets have names, while ours is just the moon? When the moon was named, people only knew about our moon. That all changed in 1610 when an Italian astronomer called Galileo Galilei discovered what we now know are the four largest moons of Jupiter.
Can people live on Mars?
However, the surface is not hospitable to humans or most known life forms due to the radiation, greatly reduced air pressure, and an atmosphere with only 0.16% oxygen. Human survival on Mars would require living in artificial Mars habitats with complex life-support systems.
Does it rain on Mars?
At present, Mars water appears to be trapped in its polar ice caps and possibly below the surface. Because of Mars very low atmospheric pressure, any water that tried to exist on the surface would quickly boil away. atmosphere as well as around mountain peaks. No precipitation falls however.