I read in an article online that in approximately 12,000 years, due to precession, Winter will occur in the Northern Hemisphere during June, July and August. Is this true? What is the relationship between the seasons and the ecliptic?
To answer your question, you first have to understand the relation between the ecliptic and seasons. The ecliptic is the path taken by the Sun relative to the stars over the year. Due to the tilt of the Earth's axis, the ecliptic plane is tilted by 23.5 degrees to the equatorial plane. So, at a certain time during the year, the Sun is directly overhead 23.5 degrees north latitude, and 6 months later, it is directly over 23.5 degrees south latitude. These two points correspond to the Summer and Winter Solstice respectively.
Due to precession, the location of the Earth's orbit at which equinoxes and solstices occur will change. Thus, the location of the current summer solstice will become the location of winter solstice 13,000 years hence. However, months are defined by seasons and so winter in the Northern hemisphere will never occur during June. At any point in future, the Northern hemisphere will experience summer during June and winter during December, but due to precesion, the months will correspond to different positions of the Earth's orbit around the Sun.
This page was last updated on June 27, 2015.