A comet is in highly elliptical orbit around the Sun. The period of the comet's orbit is 90 days. Some statements are given regarding the collision between the comet and the earth. Mark the correct statement. [Mass of the Sun = 2×1030 kg, mean distance between the earth and the Sun = 1.5×1011m.]

Using Kepler's third law, the semi-major axis of the comet's orbit is given byT2=4π2GMs×a3a=T2×GMs4π213=(90×24×3600)×6.67×10−11×2×10304π213=5.89×1010 mSo, the major axis of the comet's orbit would be2a=1.178×1011mAs 2a < mean distance between the earth and the Sun, so the collision is not possible.