Equinox on a Spinning Earth

© Meteosat 9NASAearthobservatoryRobert Simmon

When does the line between night and day become vertical? Today. Today is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator — the dividing line between day and night — becomes vertical and connects the north and south poles. The featured time-lapse video demonstrates this by displaying an entire year on planet Earth in twelve seconds. From geosynchronous orbit, the Meteosat 9 satellite recorded these infrared images of the Earth every day at the same local time. The video started at the September 2010 equinox with the terminator line being vertical. As the Earth revolved around the Sun, the terminator was seen to tilt in a way that provides less daily sunlight to the northern hemisphere, causing winter in the north. As the year progressed, the March 2011 equinox arrived halfway through the video, followed by the terminator tilting the other way, causing winter in the southern hemisphere — and summer in the north. The captured year ends again with the September equinox, concluding another of billions of trips the Earth has taken — and will take — around the Sun.

Based on Astronomy Picture Of the Day.

0 комментариев
22-09-2021, 10:26
Information
Users of Гости are not allowed to comment this publication.
Subscribe to Our Newsletter and receive the latest information about space
Уже подписались: 2
Подписаться

This resource is non-commercial and exists thanks to the hosting provider: ua-hosting.company.

The site administration is not responsible for the content of comments on the site's materials. Comments on the site's materials are the personal opinions of the site's visitors.
© «Big.Space» 2024
Мы используем файлы cookies для улучшения работы сайта. Оставаясь на нашем сайте, вы соглашаетесь с нашей Политикой в отношении обработки персональных данных. Подробнее
Принимаю