If earth got closer to the sun would the days last longer or shorter?

Question

If earth got closer to the sun would the days last longer or shorter?

Answer 1

The years would be shorter, not the days. Days are one full Earth spin, and years are circular rotations around the sun.

Answer 2

Earth's distance from the sun has no immediate bearing on the length of days. Day length is determined by the amount of time it takes the Earth to rotate once on its axis.

Now, there is a point at which the Earth could be close enough to the sun to cause tidal locking. Tidal locking is why the same side of the moon always faces the Earth. In that case, the rotation rate ("day") would approximately equal the orbital period (time to complete one orbit, or a "year").

Of course, if the Earth were that close to the sun, we wouldn't be too concerned with the length of the day - we'd have hotter topics to deal with.

Answer 3

They would get slightly longer; unless it got a lot closer, you wouldn't notice the difference without doing observations.

Answer 4

Neither, we'd just all burn.

Answer 5

If the rotation period (sidereal day) of the Earth were to remain constant then a solar day (which is what most people think of as a day) would get slightly longer since the Earth would have to travel further around to make up for the distance covered orbiting the Sun (which requires an extra 4 min over the 23 h 56 min Sidereal day at our current distance from the Sun).

Of course that's assuming that the rotation rate of Earth is constant as you move Earth closer, if it changes significantly due to any reason then that will overwhelm any effect from the orbit (Tidal locking would require the Earth to come a lot closer than Venus and would take a very long time to happen although as the Moon recedes Earth's day is gradually getting longer).

Answer 6

i think shorter because if we were closer to the sun then we would see more light more often...

the day time constists of 'light' so if we saw more light then it would stay the day time more often.

or maybe it doesnt change at all. getting closer doesnt necesarily mean that we will see more light. the earth just might heat up a little..haha like we need that !

Answer 7

at a fixed speed...it should be shorter..

Answer 8

its because of earth rotation, but for tropical region, its longer of course

Answer 9

the measurment of the length of the day is based on earth's rotational period which is about 24 hours. rotational period doesn't change on location. they year length would change. the closer it got to the sun, the less earth would have to travel inorder to revolve around the sun, making it a shorter year.

Answer 10

The length of the solar day would indeed increase. Here is the math that proves it...

Currently, the vernal equinox year (the year that most closely matches the length of the Gregorian Calendar most of the world uses) is 365.2422 24-hour days long. That is 8765.813 hours long. The Earth rotates once every 23.934 hours. So that means the Earth rotates 366.24 or so times in one year. As you can see, this is precisely one more rotation than days. This is a good hard rule. A planet that rotates in the same direction that it orbits it's star will have precisely one less solar day in it's year than the number of rotations it makes in a year (because one rotation is cancelled out by the orbit). As a side note, if the planet rotates in the opposite direction than what it orbits, it will have precisely one more solar day than the number of rotations in a year, because the orbit adds on an "extra" rotation.

So... lets say the Earth got closer and only took 7000 hours to orbit the sun. We know how long it takes for it to make a rotation, so it would rotate 292.47 times in one of these shorter years. That means there would be 291.47 solar days in this year. That would make average solar day 7000 / 291.47 = 24.016 hours long or 24 hours and 58 seconds long. The solar day has thus become slightly longer.

Answer 11

I think the length of the day is because of earth's rotation, not it's distance from the sun, so if earth moved closer to the sun our days should still be the same length.

Answer 12

The days would probably be the same, but the years would be shorter. I think it might also depend on how much closer the earth got. For example our moon, billions of years ago, was much closer. So much so that the gravitational affect it had on the Earth made the days only 6 hours long.

So if the sun could have a similar affect on the Earth, then you'd just need to move the planet closer to the sun.

Answer 13

There would be no effect on day length. The year would get shorter, though.

Answer 14

The seasons would be shorter because our rotation around the sun would accelerate, but the planet itself would continue to rotate at the same speed.

Answer 15

unchanged. the years would get shorter.

Answer 16

Feythe has it.  Our days are due to the earth's rotation, not distance from the sun.

If we were closer to the sun in a stable orbit our years would get shorter since the earth would both need to move faster and travel less distance around the sun.

For example Venus is very nearly as big as the earth but closer to the sun.  Venus orbits the sun once every 225 earth days.

EDIT:  Below Phil mentions tidal locking as a means of slowing the earth's rotation.  He is 100% correct and the earth's rotation would slow down faster closer to the sun but the effect is tiny.  There is more tidal locking effect from our own moon than the sun (currently a day is 24 hours on earth due to the moon slowing us down...a day was 23 hours long when dinosaurs ruled the earth).  That gives you an idea of the extent of the effect...1 hour difference in 65 million years.  During a human lifespan you'd need extremely accurate and sensitive scientific equipment to measure the change (but it is there).

Answer 17

everyone who has said the days would not be effected are wrong.... it may only increase the day by .0000001 seconds, but it's still a measurable effect...

to those who are still saying it woul dhave no effect....

why are summer's light-hours longer then in the winter? the earth doesn't speed up and slow down on some schedule, that's due to a slightly elliptical (oval) orbit (rather then a perfect circle) in th winter we are farther away from the sun, and we have less day light... and vice versa for summer....

the closer we get to the sun the farther to the sides (or atleast from our perspective) the sun's light is thrown, thus, the earth needs to rotate a bit more then previous to hide the suns light behind the horizon.

d**n, don't they teach you anything in school anymore?