04 Jul
Aphelion Day is the day that the Earth and Sun are at their furthest distance from each other. Every July the Earth is at aphelion, the furthest from the Sun for the year and in January it is at perihelion, the closest to the Sun for the year.
The Earth's annual orbit around the Sun will carry it to its furthest point from the Sun – its aphelion – at a distance of 1.02 AU.
The Earth's distance from the Sun varies over the course of the year because its orbit is slightly oval-shaped, following a path called an ellipse. On 5 July, the Earth reaches the point along this ellipse that is furthest from the Sun.
As a result, this moment marks the point in the year when the Sun appears smallest in the sky, and when the Earth receives the least radiation from it. In practice, however, the effect is incredibly small.
The Earth's orbit is almost exactly circular and its distance from the Sun varies by only about 3% over the course of the year, and so other phenomena, such the reflection of solar radiation by clouds, have a much more significant effect in determining our weather.
The annual changes in weather between the summer and winter months are caused entirely by the tilt of the Earth's axis of rotation, rather than by any change in its distance from the Sun.
The Earth's annual orbit around the Sun will carry it to its furthest point from the Sun – its aphelion – at a distance of 1.02 AU.
The Earth's distance from the Sun varies over the course of the year because its orbit is slightly oval-shaped, following a path called an ellipse. On 5 July, the Earth reaches the point along this ellipse that is furthest from the Sun.
As a result, this moment marks the point in the year when the Sun appears smallest in the sky, and when the Earth receives the least radiation from it. In practice, however, the effect is incredibly small.
The Earth's orbit is almost exactly circular and its distance from the Sun varies by only about 3% over the course of the year, and so other phenomena, such the reflection of solar radiation by clouds, have a much more significant effect in determining our weather.
The annual changes in weather between the summer and winter months are caused entirely by the tilt of the Earth's axis of rotation, rather than by any change in its distance from the Sun.