Are seasons unique to planets that orbit on a tilted axis like the Earth?
338419
First, all planets in our solar system are tilted, although Mercury isn't tilted much.  And yes, this is what causes seasons.\n\nWe can observe seasonal changes (growing and shrinking of polar ice caps and the dust storms they seem to induce) on Mars.  I believe Neptune also has very strange seasons that we don't know much about.\n\nOn a bigger, gaseous planet like Jupiter though, although it tilts we wont see much in the way of seasons because it's atmosphere is affected by many other things that make it turbulent as is.\n\nIn the case of Venus, it has such a wild greenhouse effect (and might be close to being perfectly upside down, I can't recall) that I don't think we will see much in the way of seasons there either.
650501
When the Earth tilts on it's axis, it moves the hemispheres either towards, or away from, the sun.  This give us seasons.  The equatorial region is the middle of the planet, and is not effected (majorly) by the tilt of the earth.  That section of the earth stays pretty much the same distance from the sun.  Since that part of the earth is closest to the sun, it's hot.  Since it's not tilted away from the sun, it's hot thru-out the year.
978616
As far as the globe - there is the Vernal Equinox (Start of Autumn in Northern Hemisphere; start of Spring in the Southern) on the 22nd of September.\n\nWinter starts in the northern hemisphere on December 22nd (start of summer in the southern hemisphere)\n\nSpring starts in the northern hemisphere on March 22nd (That is the first day of autumn in the southern hemisphere)\n\nSummer starts in the northern hemisphere on June 22nd (First day of winter in the southern)\n\nHas to do with the tilting of the earth on it's axis.
347854
It's pretty arbitrary isn't it? Look down on the North pole and the earth is turning clockwise, look down on the South Pole and it's the other way around.\n\nA more interesting question is: why are (almost) all planets orbiting and rotating in the same direction?\n\nThe solar system, earth included, is supposed to have formed from a dust cloud that contracted due to gravity. This cloud rotated in a certain way. As spin has to be conserved, all bodies in the solar system rotate in the same way.
1130994
Yes, the planets go through phases. Celestial phases are basically light hitting different hemispheres at different times.
688608
The Earth's axis is tilted at 23 and a half degrees. As the Earth orbits the Sun this tilt causes the Sun's rays to hit the Earth's surface at a more or less perpendicular angle, depending on the season. Less perpendicular is winter and more perpendicular is summer. This is also why the southern hemisphere is the opposite because it is tilted the other way in relation to the northern hemispere. There are 4 seasons equivelent to 90 degrees of the Earth's orbit. Autumn and spring equinoxes and winter and summer solstices. Jules. Australia.
614606
The earth is tilted on it's axis, roughly 23.3 degrees.  So during the summer your hemisphere of the earth is pointed toward the sun.  So you are able to enjoy a longer period of sunlight.  This is also the reason behind the lessened sunlight in winter.  Now, summer begins on the Summer Solstace, which is when the sun's rays are directly over either the tropic of capricorn or the tropic of cancer depending on which hemisphere you live.  This increase in sunlight is because the tilt of earth is placing more direct sunlight on your half of the earth.  So it takes longer for the earth to face away from the sun.
567580
The Sun rotates on its axis once in about 27 days. This rotation was first detected by observing the motion of sunspots as shown in the animation to the left. The Sun's rotation axis is tilted by about 7.25 degrees from the axis of the Earth's orbit so we see more of the Sun's north pole in September of each year and more of its south pole in March.\n\n\nEDIT: "the sun doesnt move the plantes revolve around the sun"  Your thinking of an Orbit, the earth rotates on an axis, and so does the sun, the earth circles the sun.
787984
Not as long as the earth's axis remains tilted at 23° 27’ (lets call this 24°) with respect to its orbit plane around the sun. \n\nThat is why any part of the earth north of  66° lattitude (= 90°- 24°), the Arctic Circle,  is exposed to the sun all 24 hours in the summer when the earth is leaning toward the sun. This is called the "midnight sun".\n\nHope this helps!
653187
The earth's axis of rotation is tilted with respect to its orbital plane, and remains fixed with respect to the background of stars.  Thus, the northern and southern hemispheres are alternately tilted away from the sun.  During these times, the sun's rays strike the earth's surface obliquely.  From a viewpoint on the surface, the sun appears lower in the sky and the length of daytime becomes shorter.  This effect becomes more noticeable towards the poles, and is practically nonexistent at the equator.\n\nThe earth has had this tilt since its formation.  Over time, this periodic variation in daylight gave rise to periodic weather patterns.  (The differences in distance from the sun -- perigee and apogee -- actually have little effect.)  Then, as life evolved on the planet, it adapted to the local changes in temperature.  Plants evolved to become dormant during the winter periods; or if they could not survive, their life cycles became synchronized to the yearly cycle, and their spores evolved into seeds that could withstand the colder temperatures until spring, when they could sprout.  Animals, too, evolved to adapt to the seasons, both because of the changes in temperature and the availability of plants for food.
331139
I live in Alaska, so pay attention.  The earth is tilted; it doesn't spin at a right angle to the sun.  In summer, the north pole is tilted toward the sun, and as a result, the sun appears to circle the horizon, never actually setting.  In the winter, the opposite occurs.  The sun may peak over the southern horizon, but further north it never really rises.  In spring and fall, there is no difference from the rest of the U.S.
1134535
Moon definitely rotates on its axis and the period of its rotation is exactly equal to period of its revolution. So we always see the same face. \nIf earth was to rotate on its axis in 365 days. i.e. its period of rotation would had been equal to its period of revolution.it would always keep the same face to sun and there would be no days and nights. \n ==>>Note that the fact moon keeps same face towards earth is sufficient proof that it is rotating. otherwise if it revolves around earth, we would be seing the back of moon at some  time.
963778
Eliptical orbits. If the orbit were circular, then you'd expect the period to be the same. ...The planet speeds up and slows down and spends more time at the part of the orbit more distant from the sun.
272536
yes--look:\nhttp://www.nasa.gov/audience/forstudents/k-4/home/F_Planet_Seasons.html
526984
NO, angle of the earth on it's axis limits sunlight for a few months. The days never warm up.
351070
Saturn's rings are always inclined about 30 degrees; the planet's tilt does not change, at least not on any human timescale.  When we see different parts of the ring, as you've surmised, it is a seasonal effect, as the illumination changes over the orbit.  \n\nWhen the rings are edge-on, think of it as being Saturn's equivalent of spring or fall; when they're at full tilt, think of it as summer or winter (depending on the hemisphere).
619864
If you were to view the Earth from above the North Pole, it will be rotating in an anticlockwise direction (i.e. West to East).\n\nEarth rotates about an axis, where 1 rotation equates to 24 hours (1 day). This axis is at a tilt of 23.45 degrees from the vertical. This tilting results in the seasons.\n\nA cool "video" can be found on: http://www.ncsu.edu/scivis/lessons/earthinspace3d/earth2.html