DOOMSDAY

Introduction:
     Many have wondered what would happen if two planets where to cross paths and crash. Would it affect the whole solar system? I such an event even possible? To fully answer these questions, you would need to have a good understanding of how our solar system works. This involves knowing how planets move in our solar system and what keeps them on their own individual tracks. In this site we will be going over less detailed facts.

Return to top

Description of planets:
     As most people know, there are nine planets in our solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The first four planets, also known as the inner planets, are the most dense planets. The rest, outer planets, are less denser because of their gaseous composition. Below is a brief summary of each planet.

Mercury
 

Atmosphere	Mercury has almost no atmosphere.
Size	3031 miles in diameter. Mercury is the 2nd smallest planet in our solar system.
Mass	3.3 x 10^23 kg which is about 1/20th of Earth's mass.
Gravity	Mercury's gravity is equal to 38% of Earth's gravity.
Orbit	On average Mercury is at a distance of 0.387 AU from the sun

Return

Venus
 

Atmosphere	Venus' atmosphere can be described as poisonous heat that will literally cook a person.
Size	7521 miles in diameter. Venus is the 4th smallest planet in our solar system.
Mass	3.3 x 10^23 kg. Venus has the same mass as Mercury
Gravity	Venus' gravity is equal to 91% of Earth's gravity.
Orbit	On average Venus is at a distance of 0.72 AU from the sun (Note: Venus seems to orbit the sun in the opposite direction of all other planets in our solar system.)

Return

Earth
 

Atmosphere
Size	7926 miles in diameter. Earth is the 5th largest planet in our solar system.
Mass	5.98 x 10^24 kg.
Gravity	To escape Earth's gravity, an object must be traveling at a speed of 24,840 mph.
Orbit	On average Earth is at a distance of 1 AU

Return

Mars
 

Atmosphere	Mars' atmosphere is very thin.
Size	4222 miles in diameter. Mars is the 3rd smallest planet in our solar system.
Mass	6.42 x 10^23 kg which is about 1/9th of Earth's mass.
Gravity	Mars gravity is equal to 38% of Earth's gravity.
Orbit	On average Mars is at a distance of 1.523 AU from the sun.

Return

Jupiter
 

Atmosphere	Jupiter's atmosphere can be described as thick.
Size	887000 miles in diameter. Jupiter is the largest planet in our solar system. (The Earth can fit 11 times inside of Jupiter if it was hollow.)
Mass	1.9 x 10^27 kg which is about 318 times greater than Earth's mass.
Gravity	Jupiter gravity is  254% percent stronger than Earth's gravity
Orbit	On average Jupiter is at a distance of 5.161 AU from the sun.

Return

Saturn
 

Atmosphere	Saturn's atmosphere can be described as cloudy and very gaseous.
Size	74898 miles in diameter. Saturn is the 2nd largest planet in our solar system.
Mass	5.69 x 10^26 kg which is about 95 times greater than Earth's mass.
Gravity	Saturn's gravity is 1.08 times stronger than Earth's gravity. (Note: A 100 pound object on Earth would weight 108 pounds on Saturn.)
Orbit	On average Saturn is at a distance of 9.539 AU from the sun.

Return

Uranus
 

Atmosphere	Uranus' atmosphere can be described as cloudy.
Size	31690 miles in diameter. Uranus is the 3rd largest planet in our solar system.
Mass	8.68 x 10^25 kg which is about 14 times greater than Earth's mass.
Gravity	Uranus' gravity is 91% of Earth's gravity.
Orbit	On average Uranus is at a distance of 19.18 AU from the sun.

Return

Neptune
 

Atmosphere	Neptune's atmosphere can be described as hazy, with strong winds.
Size	30775 miles in diameter. Neptune is the 4th largest planet in our solar system.
Mass	1.02 x 10^26 kg which is about 17 times greater than Earth's mass.
Gravity	Neptune's gravity is 1.19 times greater than Earth's gravity.
Orbit	On average Neptune is at a distance of 30.06 AU from the sun.

Return

Pluto
 

Atmosphere	Pluto's atmosphere is not known.
Size	1429 miles in diameter. Pluto is the smallest planet in our solar system.
Mass	1.29 x 10^22 kg which is about 1/500th of Earth's mass.
Gravity	Pluto's gravity is about 8% of the Earth's gravity.
Orbit	Pluto's orbits is very eccentric. Sometimes Pluto is closer to the Sun than Neptune, and sometimes further. So an average of Pluto's distance from the Sun would not be accurate.

Return
 

Solar System Design:
     The planets seem to be on a circular path around the sun, but they are not. Their path's are described as ellipses. An ellipse can be described as a stretched circle with two center points. The Sun is always at one of the center points in a orbit's path. This is Kepler's Law #1. Since the Sun is at one center (focal) point, when a planet nears that focal point it travels faster. As it goes further away from the Sun, the planet travels slower. The reason for this change in  velocity has to due with the Sun's gravitational pull. Now all ellipses are not the same. Some are more curved than others, and some are longer than others. Scientists use eccentricity to describe each planet's orbital path shape.
     Gravity also has a major role in each planets orbital path. Gravity is what keeps each planet on track and not flying all over the place. However, gravity is a two way street in space. Just as the Sun applies its gravity on all planets in our solar system, each planet applies its own gravity back on the Sun. Since the Sun is so massive, the planets can't move the Sun with their gravity and are forced to move around the Sun.  Since there is so much gravity, what keeps the planets from being pulled into the Sun?. The answer has to deal with a planets speed.
     All planets in our solar system move around the sun at their own speeds. They each move at different speeds because the Sun's gravity affects each planet at different distances. As mentioned before, when the a planet is closer to the Sun it travels faster than when it is further away. The closer to the Sun the stronger the gravity becomes resulting in more speed an object needs to escape its gravity. However, the planets work in a way that they don't have enough speed to escape the Sun's gravity, but enough not to be pulled in by the Sun's gravity. This state of equilibrium is what keeps the planets in orbit around the Sun.

Return to top

Conclusion:
     Is there a possibility that planets will crash into each other? The answer is no. Our solar system was designed to be stable. There are many forces (such as gravity and velocity) that are acting on the planets to keep them stable. The planets move at their own pace and in their own paths. The only two planets that do cross paths are Neptune and Pluto and they have no chance of meeting. Also, if you noticed from above, each planet has a great deal of mass, which requires a great deal of energy to affect it. So far, there is no object with such energy in our solar system other than the Sun. In the end the Earth will not be destroyed by other planets.

Return to top

• AU (Astronomical Unit) - The average distance from the Earth to the Sun. 1 AU is 92,960,116 miles (149,597,870 kilometers)

• Eccentric - a non-circular path.

• Eccentricity - a value that defines the shape of an ellipse or planetary orbit.

• Equilibrium - a state of balance between opposing forces or actions.

• Kepler's Law #1 - The orbit of a planet/comet about the Sun in an ellipse with the Sun's center of mass at one focus(center point).