2007-10-28 13:24:28 · 17 answers · asked by bearzer83 1 in Science & Mathematics ➔ Astronomy & Space
At its closest to the Sun (perihelion) Earth is having winter in the northern hemisphere and summer in the southern. The seasons are caused by the tilt of Earth's axis - when you're tilted away from the Sun, you've got winter. The eccentricity of Earth's orbit is fairly small, so the difference in distance does not make much difference in the amount of heat we get from the Sun. It does mean that northern hemisphere winters are just slightly warmer and shorter than southern hemisphere winters - shorter because planets move faster at perihelion. Mars has a more eccentric orbit and the difference in the length and temperature of winter in the two hemispheres is much greater as a result.
2007-10-28 13:37:42 · answer #1 · answered by injanier 7 · 1⤊ 0⤋
If you stop to realize that when it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere, and since all of the Earth is still at the same distance from the sun at any time, you should see that the distance from the sun is not cause of the seasons. The seasons are the result of the angle between the daily rotation of the Earth around its poles and the Earth's revolution around the sun. The primary cause of the seasons is the 23.5 degree of the Earth's rotation axis with respect to the plane of the ecliptic, which is the plane of the Earth's movement around the sun. This means that as the Earth goes around in its solar orbit, the Northern hemisphere is at various times oriented more toward and more away from the Sun, and likewise for the Southern hemisphere.
2007-10-28 20:41:01 · answer #2 · answered by Boris Bumpley 5 · 1⤊ 0⤋
OK first of all the Earth is the 3rd planet from the sun, so it's not the closest. Mercury is. 2ND of all we have winter because when the Earth rotates part of it is facing away from the sun, away from the warmth. the side that is away from the sun is winter while the side that is closest to the sun is having summer. the sides in between are having either fall or spring. This is only beacause Earth's axis is tilted.
2007-10-28 20:31:51 · answer #3 · answered by tiffanyy =:] 1 · 1⤊ 0⤋
It doesn't matter how close the planet is. What matters is which hemisphere is angled at the sun. If you notice we have the shortest days and longest nights in winter. This is due to the fact that the Earth is on an axis and doesn't spin in a normal fashion. The seasons are determined by which way we are tilted in relation to the sun, not distance.
2007-10-28 20:26:47 · answer #4 · answered by Grumble 4 · 2⤊ 0⤋
Its the angle of the earth in proportion to the sun is why we experience the four seasons. Th earth is on a twenty degree axis, and when we orbit the the northern hemisphere pointed away from the sun, thats our winter and this is why Australia and New Zealand have a Summer Christmas.
2007-10-28 20:39:11 · answer #5 · answered by neil_gormley 1 · 1⤊ 0⤋
it all depends on how direct the sun's rays are. In the summer the sun is farther away but they rays are more direct, however in the winter the sun may be closer but the rays are much more indirect. You could demonstrate this by holding a flashlight directly on top of a table (summer) then tilting it to a side and on the outskirts of the light region you will find the light to be not as bright (winter)
2007-10-28 20:30:08 · answer #6 · answered by burnsie 2 · 1⤊ 0⤋
We do not, the reason winter comes is that the (I am assuming you are in the USA) Northern Hemisphere is further away from the sun in the "winter" months. Meanwhile are friends in Australia are having summer right now.
So who is having Winter/Summer changes with the tilt of the earth.
Here is a link for you.
2007-10-28 20:29:05 · answer #7 · answered by gator_ce 5 · 1⤊ 0⤋
Because the northern hemisphere is turned away from the sun. (I am assuming that you live in the northern hemishere.)
The earth tilts on its axis as it rotates around the sun. This also accounts for the shortening of days from Sept21st to Dec 21st.
The southern hemisphere enjoys summer and longer days while we are freezing. Ask any Australian.
2007-10-28 20:29:20 · answer #8 · answered by oldsalt 7 · 1⤊ 0⤋
Because in the winter in the northern hemisphere the north pole is pointing away from the sun and the south pole is pointing toward so it is summer in the southern hemispere. likewise when it is summer in the north, the north pole is pointing at the sun and away from it in the south.
2007-10-28 20:28:34 · answer #9 · answered by Petero 6 · 1⤊ 0⤋
We winter when our hemisphere is tilted away from the sun, when the suns rays are least direct, thus least intense.
2007-10-28 20:27:24 · answer #10 · answered by CinderBlock 5 · 1⤊ 0⤋