 channel for physics please subscribe my channel hello and welcome back to another episode of physics partner as per promise today I brought the second part of the space physics which is newly injected in IGCSE curriculum for the code 0625 and 0972 in this part we will focus on our solar system elliptical orbit and some planet data comparisons the Sun is a star like other star exists in the universe the Sun is about 150 million kilometers from earth and without its energy life as we know it could not exist here on over home planet earth the earth is one of the eight planets that travel around the Sun the eight planets in order of distance are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune Mercury is the closest to the Sun Neptune is the farthest the solar system is also home of lots of asteroids moons and dwarf planets such as Pluto what is the moon moon is a natural satellite revolving around over earth so what is a dwarf planet the object called dwarf planets are similar to the solar system eight planets but they are smaller in size what are asteroids any of the small rocky celestial's bodies found especially between the orbit of Mars and Jupiter are called asteroids the region of interplanetary space between the orbits of Mars and Jupiter in which more asteroids are found is considered as asteroid belt let's talk about the orbits around the Sun you might think that the earth orbits the Sun is a perfect circle but actually it's more like an oval we call the shapes of the earth orbit elliptical this mean its shape like an ellipse an ellipse is a circle which has been squashed or flattened a bit all eight planets in our solar system travel around the Sun in elliptical orbits not all ellipses are the same Sun is not at the center of the elliptical orbit except when the orbit is approximately circular over many years data about all the planets moons and the Sun have been collected by the astronomers and scientists this is not just for general knowledge but also to indicate and understand the pattern factors that affect conditions on the surface of the planets environmental problems during the visit through spaceships or robots would encounter look at the chart on your screen look at the data very carefully but don't worry you don't need to remember any number for IGCC exams but you should know how to analyze and interpret planetary data about orbital distance orbital duration density surface temperature and uniform gravitational field strength at the planet surface there are some observable common themes from the data of the planet for example you can see here orbiter duration like means how long it takes to travel around the Sun increases with orbital distance like distance from the Sun similarly the circular path that plans travel in has a larger radius orbital duration increases with orbital distance you can see here in the data for example naphtune travels much slower than mercury the planets further away from the Sun experience a weaker gravitational pull so moves slower in their orbits surface temperature decreases with orbital distance except for Venus Venus has dense atmosphere of carbon dioxide trapping in heat through the greenhouse effect the surface gravitational field strength does not change depend on the planet size but also its mass this is why although Uranus is four times larger than Earth it has a smaller gravitational field strength because it has less dense I think that's enough for today thank you very much for your listening I hope you enjoyed the video and I hope it is very useful as well don't hesitate to write an email to your physics partner if you have any further question curie comment suggestion or even critic you can contact your physics partner for online classes as well take care of yourself see you in the next video goodbye