{"id":42405,"date":"2023-03-08T11:38:24","date_gmt":"2023-03-08T11:38:24","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=116727"},"modified":"2023-03-08T13:32:31","modified_gmt":"2023-03-08T13:32:31","slug":"what-causes-seasons-on-earth","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/what-causes-seasons-on-earth\/","title":{"rendered":"What causes seasons on Earth?"},"content":{"rendered":"

How does Earth’s orbit around the Sun cause the changes from spring to summer to autumn to winter? <\/p>

By Russell Deeks\n \t\t<\/p>

Published: Wednesday, 08 March 2023 at 12:00 am<\/p>

\n\n

As every schoolchild (hopefully!) knows, Earth orbits the Sun.<\/p>\n

But this is not simply a case of one perfectly spherical object orbiting in a perfect circle around another spherical object in a flat plane.<\/p>\n

And it\u2019s the differences in Earth\u2019s position relative to the Sun that produces the variations in average temperature, in the weather and in the length of the day that we call the seasons.<\/p>\n

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A diagram showing how Earth orbits the Sun. Credit: Adrian Dean<\/span><\/figcaption><\/div>\n

Earth\u2019s orbit around the Sun<\/a> is slightly oval, rather than round, which means there are times when Earth is closer to the Sun, and times when it is further away.<\/p>\n

The points at which Earth is closest to or furthest from its parent star are called \u2018perihelion\u2019 and \u2018aphelion\u2019, respectively, and on the face of it, that should explain the seasons.<\/p>\n

The nearer you are to the Sun, the warmer it\u2019s going to be, surely?<\/p>\n

Except that it doesn\u2019t work like that \u2013 in fact, Earth reaches its closest point to the Sun (perihelion) right in the middle of what we in the northern hemisphere call winter!<\/p>\n