Planet in our Solar System
1. Mercury
- The closest planet to the sun.
- Mercury is only a bit larger than Earth's moon
Discovery - Known to the ancients and visible to thenaked eye
Diameter - 3,031 miles (4,878 km).
Orbit - 88 Earth days
Day - 58.6 Earth days.
2. Venus
- The second planet from the sun.
- Venus is hotter than Mercury.
- The pressure at the surface would crush and kill you.
- Venus spins slowly in the opposite direction of mostplanets.
Discovery - Known to the ancients and visible to thenaked eye.
Diameter - 7,521 miles (12,104 km).
Orbit - 225 Earth days.
Day - 241 Earth days.
3. Earth
- Earth is third planet from the sun
- Earth is a waterworld, with two-thirds of the planetcovered by ocean
- Earth atmosphere is rich in life-sustaining nitrogenand oxygen
- Surface of Earth rotates about its axis at 1,532 feetper second
Diameter - 7,926 miles (12,760 km)
Orbit - 365.24 days
Day - 23 hours, 56 minutes.
4. Mars
- Mars is fourth planet from the sun
- Mars is a cold, dusty place.
- The dust, an iron oxide, gives the planet its reddishcast
- Mars has mountains and valleys.
- Scientists think ancient Mars would have had the conditionsto support life
Discovery - Known to the ancients and visible to thenaked eye
Diameter - 4,217 miles (6,787 km)
Orbit - 687 Earth days
Day - Just more than one Earth day (24 hours, 37minutes).
5. Jupiter
- Jupiter is fifth planet from the sun
- Jupiter is huge and is the most massive planet in oursolar system
- It is a mostly gaseous world, mostly hydrogen andhelium.
- Its swirling clouds are colorful due to different typesof trace gases
- A big feature is the Great Red Spot, a giant storm whichhas raged for hundreds of years
- Jupiter has a strong magnetic field
Discovery - Known to the ancients and visible to thenaked eye
Diameter - 86,881 miles (139,822 km)
Orbit - 11.9 Earth years
Day - 9.8 Earth hours
6. Saturn
- Saturn is sixth planet from the sun.
- When Galileo Galilei first studied Saturn in the early1600s, he thought it was an object with three parts.
- More than 40 years later, Christiaan Huygens proposedthat they were rings
- The rings are made of ice and rock.
- Scientists are not yet sure how they formed.
- The gaseous planet is mostly hydrogen and helium
- It has numerous moons.
Discovery - Known to the ancients and visible to thenaked eye
Diameter - 74,900 miles (120,500 km)
Orbit - 29.5 Earth years
Day - About 10.5 Earth hours.
7. Uranus
- Uranus is seventh planet from the sun
- Uranus is an oddball
- Astronomers think the planet collided with some otherplanet-size object long ago, causing the tilt
- Uranus is about the same size as Neptune
- Methane in the atmosphere gives Uranus its blue-greentint
- It has numerous moons and faint rings.
Discovery - 1781 by William Herschel (was thoughtpreviously to be a star)
Diameter - 31,763 miles (51,120 km)
Orbit - 84 Earth years
Day - 18 Earth hours.
8. Neptune
- Neptune is eighth planet from the sun.
- Neptune is known for strong winds - sometimes fasterthan the speed of sound.
- Neptune is far out and cold
- The planet is more than 30 times as far from the sun asEarth
- Neptune was the first planet to be predicted to existby using math, before it was detected
- Neptune is about 17 times as massive as Earth
Discovery - 1846
Diameter - 30,775 miles (49,530 km)
Orbit - 165 Earth years
Day - 19 Earth hours
9. Pluto (Dwarf Planet)
- Pluto is ninth planet from the sun
- It is smaller than Earth moon
- Its orbit carries it inside the orbit of Neptune andthen way out beyond that orbit
- Pluto will stay beyond Neptune for 228 years
- It is a cold, rocky world with only a very ephemeralatmosphere.
Discovery - 1930 by Clyde Tombaugh
Diameter - 1,430 miles (2,301 km)
Orbit - 248 Earth years
Day - 6.4 Earth day.