If you thought that we were the warmest in our Northern Hemisphere summer because the Earth is closest to the sun then, you are in good company with Harvard students (according to a videotaped survey my husband uses in his intro meteorology class) but scientifically wrong. Today is actually Aphelion, the day when the Earth is farthest from the sun in its yearly orbit. The opposite of aphelion is perihelion, which occurs in our Northern Hemisphere winter (I keep track of the difference by thinking “a” for away). Our seasons are actually caused by the tilt of the Earth’s rotational axis, which tilts towards the sun in our summer, and away in our winter.
