IGCSE›Cambridge IGCSE Physics›Mind mapsThe Solar SystemCambridge IGCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsWhat is in it?The Sun holds most of the massEight planets, Mercury to NeptuneDwarf planets and asteroids, mainly between Mars and JupiterMoons orbit planets; comets have tails near the SunInner vs outerInner: rocky, small, dense, few moonsOuter: gaseous, large, low density, many moonsNear the Sun, heat stopped light gases condensingFar out, gravity held on hydrogen and heliumGravityField strength rises with planet massFalls with distance squaredDouble the distance: one-quarter the strengthSolar Systemplanets and orbitsAUcccOrbitsSun's gravity gives the centripetal forceOrbits are ellipticalSun sits at one focusCloser to the Sun means fasterLight travelc=3.00×108 m/sc = 3.00 \times 10^8\,\text{m/s}c=3.00×108m/st=dct = \frac{d}{c}t=cdSun to Earth: about 500 sSun to Neptune light: about 4.3 hoursExam tipsList planets in order from the SunExplain speed using energy: less PE, more KELink temperature and gravity to planet types