solar system

• The Sun's diameter is approximately 1.39 million kilometers (864,938 miles) across.
• The Sun has an average temperature of about 5,500 degrees Celsius (10,000 Fahrenheit).
• The Sun is the largest object in our Solar System.
• The Sun is classified as a yellow dwarf star because it emits light that appears yellowish-white to human eyes.
• The Sun rotates on its axis once every 27 days at the equator but takes longer to complete one rotation nearer the poles.
• The Sun is composed mostly of hydrogen and helium gas.
• The Sun


  A star, a ball of incandescent gas whose light and heat are generated by nuclear reactions in its core
• The Sun


  • It is by far the largest body in the Solar System— more than 700 times the mass of all the other bodies put together
  • Its gravitational force holds the planets and other bodies in the system in their orbital patterns about it
• The Sun's family is called the Solar System
• The Sun


  • It is a huge ball of hydrogen and helium held together by its own gravity
  • It has several regions including the core, the radiative zone, and the convection zone
• Yellow Dwarf Star


  • The current state of the Sun, which is about 4.5 billion years old
  • In 5 billion years, it will become a red giant and then a white dwarf star
• It takes the Sun 250 million years to complete one revolution around the galactic center of the Milky Way Galaxy
• Planets


  • They are much smaller than the Sun and orbit about it in nearly circular orbits
  • They emit no visible light of their own but shine by reflected sunlight

  
• Terrestrial planets


  • Mercury
  • Venus
  • Earth
  • Mars
• Jovian planets


  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• Planet


  • It must orbit a star (in our cosmic neighborhood, the Sun)
  • It must be big enough to have enough gravity to force it into a spherical shape
  • It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun
• Asteroids


  Rocky objects that orbit the Sun, smaller than planets but larger than meteoroids
• Comets


  Small icy dirtballs that orbit the Sun, made of ice and dust
• Kuiper Belt


  A region of icy, comet-like bodies that surrounds the solar system
• Oort Cloud


  A much more distant region of icy, comet-like bodies that surrounds the solar system, including the Kuiper Belt
• Mercury


  • The smallest planet in our solar system and nearest to the Sun
  • From the surface of Mercury, the Sun would appear more than three times as large as it does when viewed from Earth, and the sunlight would be as much as seven times brighter
  • Despite its proximity to the Sun, Mercury is not the hottest planet in our solar system
• Venus


  • The first planet to be explored by a spacecraft - NASA's Mariner 2 in 1962
  • It takes 243 earth days for Venus to complete one rotation on its axis
• Earth


  • The fifth-largest planet in the solar system, smaller than the gas giants but larger than the other rocky planets
  • It takes Earth 23.934 hours to complete a rotation on its axis and 365.26 days to complete an orbit around the sun
• Mars


  • The fourth planet from the sun with a distinct rusty red appearance and two unusual moons
  • It has a very thin atmosphere, but the dusty, lifeless (as far as we know it) planet is far from dull
  • The bright rust color is due to iron-rich minerals in its regolith
• Jupiter


  • The largest planet in the solar system and the fifth planet from the sun
  • Its most prominent and most famous storm is the Great Red Spot, twice the width of Earth
  • Jupiter helped to revolutionize the way we saw the universe in 1610 when Galileo discovered its four large moons
• Saturn


  • The sixth planet from the sun and the second-largest planet in the solar system
  • It has a whopping 63 official moons with another 20 awaiting confirmation
  • It's the farthest planet from Earth that's visible to the unaided eye, but its rings are better viewed through a telescope
• Uranus


  • The seventh planet from the sun and the third largest planet in the solar system
  • It was long mistaken as a star because of its dimness and slow orbit
  • Uranus is blue-green in color, as a result of the methane in its mostly hydrogen-helium atmosphere
  • Uranus is often dubbed an ice giant, since at least 80% of its mass is a fluid mix of water, methane and ammonia ice
• Neptune


  • The eighth and farthest planet from the sun, but not the coldest
  • Neptune's rocky core is surrounded by a slushy fluid mix of water, ammonia and methane ice
  • Because of the high temperatures and pressures, scientists believe compressed carbon in the form of diamonds causes a "diamond rain" phenomenon on Neptune and Uranus
• photosphere is the surface of the sun and the chromosphere is the boundary of photosphere and corona
• photosphere is made of plasma
• sunspots are dark spots on the surface of the Sun caused by intense magnetic fields
• the sunspot cycle lasts about 11 years
• According to NASA, a planet should be

  It must orbit a star (in our cosmic neighborhood, the Sun).

  • It must be big enough to have enough gravity to force it into a spherical shape.

  • It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun..
• The proponent of the planetesimal hypothesis is Geologist Thomas Chrowder Chamberlin and Astronomer Forest Ray Moulton in 1905
• The Planetesimal hypothesis states that the planets were formed by the accumulation of extremely small bits of matter planetesimals that revolved around the sun. This matter was produced when a passing star almost collided with the sun. During the near-collision, hot gases were pulled out of both stars and the gases then condensed.
• The nebular hypothesis states that the Solar System began as a rotating cloud of gas and dust called a nebula. The gravitational pull from this spinning mass eventually drew together to form the Sun at the center. As the remaining material continued to spin, it flattened into a disk. Eventually, clumps of rocky debris coalesced into asteroids and comets. These bodies grew larger until they became large enough to attract more material and become planets.
• Oort Cloud is a hypothetical sphere surrounding the Sun containing trillions of icy bodies left over from the formation of the Solar System
• Capture Theory

  Our planets and moons were wandering around in space and the moons were captured by the planets
• Capture Theory of the Origin of the Solar System


  Proposing that the solar system formed through the capture of material from a diffuse star that passed close to the sun
• Woolfson's capture theory was put forward


  1964