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What if the sun disappeared for a week?

        Science | What If

The first thing you'd notice if the sun disappeared is that Earth would get cold and dark pretty quickly.
The first thing you'd notice if the sun disappeared is that Earth would get cold and dark pretty quickly.
Andrew_Mayovskyy/ThinkStock

If you happen to live in one of the many areas of the world that are prone to long, cold and dark winters – or even short, cold and dark winters – then your day-to-day life gets appreciably more pleasant when the sun comes out and the flowers start to bloom. Folks tend to get jazzed about spring because it means packing away puffy coats and leaving the office before the sky turns black. In moderation, the sun does a body good. It helps get you out of bed in the morning, strengthens your bones with vitamin D and might ward off a seasonal form of depression [source: Loria].

In other words, we'd all be sleepy weaklings battling psychological issues if the sun suddenly took a week's vacation. While it would certainly harsh the mellow of beachgoers, losing the sun would also have a more immediate and significant impact on the planet and the people who inhabit it [sources: Otterbein, EarthSky].

The first thing that you'd probably notice is that the planet would become pretty dark and pretty cold pretty darn quick. Although it may not feel like it, Earth is constantly spinning. This rotation is marked in calendar days: The daylight hours are those during which your particular place on the planet rotates toward the sun, and the night falls as the same spot rotates away. If the sun disappeared, the day would bleed into night in about 8.5 minutes, the time it takes for the sun's light to reach us here on Earth [sources: Otterbein, EarthSky].

The cold spell would be less severe and not as immediate as the shift to near darkness. The planet's temperature would drop to about zero degrees Fahrenheit (minus 17.8 degrees Celsius) over the course of the week. That's certainly chilly, but it's not enough to freeze off the human race and other forms of life on the planet. Not right away, at least. No sun means no photosynthesis, the process by which plants convert sunlight into energy. As plant life begins to wither and die, animals that eat it would be left without sustenance [sources: Otterbein, EarthSky]. (It would take about a full year for surface temperatures to plummet to minus 100 degrees Fahrenheit (minus 73.3 degrees Celsius). The frost wouldn't only be on the pumpkin at that point, it would also be severe enough that humans and many other life forms wouldn't be able to survive without a steady source of energy and heat [sources: Otterbein, EarthSky].

The biggest impact of the sun taking a powder for a week wouldn't be on Earth's surface, but in outer space. At the same time that our planet is constantly spinning, it's also orbiting around the sun. The sun has a diameter roughly 100 times that of Earth and exerts a gravitational pull on all the planets in our solar system. Gravity causes our planet to circle around that big star in the sky. Without gravity, the planet would simply float off into space. Among other dangers, Earth could eventually slam into a comet, meteor or even another planet. Let's just hope that it has its own sun and some decent beaches [sources: NASA, Otterbein, EarthSky].

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