Maria Trepp's

I have not read anything yet about Kepler-22b’s axis: is it tilted to provide seasons?

Seasons on Earth are caused by the fact that the axis of the Earth is tilted:

The Earth rotates around the Sun in a plane called Ecliptic . The rotational axis of the Earth is tilted with an angle of 23,45° between the Earth’s equator and orbit plane. The tilted Earth moves around the Sun in a parallel position, so that the Northern hemisphere is closer to the Sun in June, and the Southern hemisphere is closer to the Sun in December:

The Sun’s light on the Erath in different seasons

Christiaan Huygens writes in his last book Cosmotheoros (1698) about intelligent life on other planets. He is putting himself in the mental position of all planets and describes what an observer on each planet will see. He describes the seasons on all the planets as well as he can.

He starts with Mercury. This planet is close to the Sun and was very difficult to observe for Huygens. Thus Huygens did not know if Mercury’s axis was tilted and if Mercury had seasons- but we know now that this planet is not tilted and has no seasons. About Venus Huygens does not know much either, but we know that Venus, like Mercury, is almost not tilted. Huygens writes about Mars, and assumes that Mars has no seasons- but we know now, that Mars is tilted as much as Earth is.

But Huygens is right about Jupiter: no tilted axis, no seasons.

And then Saturn, Huygens’ favorite planet: there the differenece between summer and winter is even greater than on Earth, because Saturn is even more tilted than Earth. Huygens, who firmly believes in inhabitants in Saturn is unsure if they can live close to Saturn’s poles, because it will be too cold there.