Happy Aphelion: Distance From Earth To Sun Is Farthest Today
If you see Earth today, be sure to wish you a happy aphelion – July 3 marks the day of this year when our planet has reached the point of its orbit that is further from the sun.
The Earth does not revolve around the center of the solar system in a perfect circle. Because its orbit is more elliptical, there is a point that is closer to the sun, the perihelion and aphelion a point more distant.
Perihelion occurred on January 4 of this year, and six months ago, Earth has reached the other end of its orbit as it continues its perpetual journey around the sun.
That’s a difference of a few million miles. In periélonie in January the Earth was 91.4 million miles from the sun. Today, more precisely 4:11 p.m. EDT, Earth has reached 94.5 million miles away from our star.
The average distance between Earth and the sun is somewhere in the middle, and is commonly known in astronomy as being equal to 1 astronomical unit.
With regard to light years, it is about 8 minutes of sunlight – it takes light from our star so long to reach our planet.
If you live in the Northern Hemisphere, one question that might come to mind today is why, if the Earth is further away from it, will the sun be this year, is it so hot? Although it is actually winter and quite cold in some parts of the southern hemisphere, the temperature of the Earth is not related to these small variations in its orbit. In fact, a distance of a few million miles is not really important in the large space scheme.
The Earth revolves around the Sun in an elliptical orbit, the point of our most distant star being its aphelion and the perihelion being the closest. Photo: NASA / JPL
The seasons and changes in temperature do not come from the inclination of the planet on its axis: when the northern hemisphere is inclined towards the sun, and therefore, at the same time, the southern hemisphere is inclined, it is warm north and more Cold in the south.
This also explains why aphelion and perihelion do not coincide with the longest and shortest days of the year – the dates, the summer and winter solstices, are related to the inclination of the Earth’s axis and its forward movement and return.
One of the ways in which the distance from the sun affects the seasons of the year is that the Earth moves faster in its orbit when it is closer to the sun and a little slower when it is further away due to the fluctuations of its Kinetic energy gradually as it moves.
The Earth is typically around 67 000 mph, but it moves about half a mile per second slower at aphelion than during perihelion.
EarthSky says that for this reason, summer lasts a little longer in the northern hemisphere – about five days – in winter. This means that winter is more than five summer days in the southern hemisphere.
It is not new that Earth reaches aphelion in early January and early July, respectively, occurs at about the same time each year.