miércoles, 4 de noviembre de 2015

Days, nights and seasons

Long time ago, Ancient Greeks thought that the Earth was motionless and in the center of  the Universe. Sun appears to move through the sky from East to West. So, days and nights were explained because the Sun revolved around the Earth. Years later, Copernicus was convinced that the Earth was a planet too; so, he proposed that our planet has two motions: rotation, spining around it axis, and orbital motion, around the Sun.
As result of rotation, the Sun lights up half of the Earth and the other half is in shadow. It’s day time when Granada is in the lit by the Sun; it is night-time here when our part of the planet is facing away from the Sun. The Earth’s axis, the imaginary line through the centre of the planet, is tilted compared to the way the Earth orbits the Sun.  

As result of orbital motion, the Earth goes once around the Sun every 365 days. That is one Earth  year. And every year has four seasons: winter, spring, autumn (fall) and summer. Seasons are mostly due to the tilt of the axis. In summer, the Northen Hemisphere is tilted to the Sun, so it spends more time facing the Sun and days are longer than nights and the weather is warm. In winter, the Northen Hemisphere is tilted away  from the Sun, so, nights are longer than days and the weather is cold.

In my opinion, it’s clear the mecanism of seasons in our planet. But the Earth is not the only planet in the Solar System. Here you have a picture whit all the planet (including the dwarf one, Pluto). Can you tell what planets do have seasons? Why? Please, write your answer as a comment (Spanish version).

23 comentarios:

  1. My opinion is that Mercury,Venus and Jupite, they have a very small slope, because ,can not have stations.The earth, mars,salum and neptune yes why its axis bis inclined enoungh to have stations.And uranus it is a strange case.

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  2. The Earth, Mars, Saturn, Neptune and Pluto have seasons because their axis are inclinaton respect to their orbits.

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  3. The Earth, Mars, Saturn, Neptune and Pluto have seasons because their axis are inclinaton respect to their orbits.
    Pablo Delgado Alaminos

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  4. Other planet have seasons is Mars, because have got similar grade of rotation

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  5. I think that Mars,Saturn and Neptune have got seasons because his axis is enough inclined such as to receive the Sun´s rays in different ways

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  6. The Earth, Mars, Saturn and Neptune are planets that have stations.

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  7. I think Mars, Saturn and Neptune are the planets can have seasons because their axis of rotation are inclined respect to their
    orbits.

    Paula Duro Muñoz.

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  8. I think Mars, Saturn and Neptune because have got its axis is inclined sufficiently for it

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  9. Noemí Castillo Tejada22 de noviembre de 2015, 9:57

    The Earth, Mars, Saturn and Neptune. The others hasn't got seasons because the obliquity of the planets aren't inclined.

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  10. The biggest planet is Jupiter and the planet more boy is Pluto. And Saturn is the only one that has ring.

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  11. Tania Castillo Tejada22 de noviembre de 2015, 14:15

    The biggest planet is Jupiter and the planet more boy is Pluto. And Saturn is the only that has ring.

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  12. The Earth, Mars, Saturn and Neptune have got seasons missing planets have don´t seasons

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  13. The Eart, Mars, Saturn and Neptune have got seasons missing planets have don´t seasons.
    Ainhoa Balderas Cánovas.

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  14. The planets that have got seasons are... because they have their axis tilted.
    Antonio

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  15. have seasons earth mars saturn uranus and neptune

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  16. In my opinion, Earth, Mars, Saturn, Neptune, Uranus and Pluto have seasons because their axis is, in comparasion with the Earth's enough inclined for having seasons

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  17. Belén Díaz Gutiérrez25 de noviembre de 2015, 11:53

    Mercury and Jupiter hasn´t got seasons because its axis is almost perpendicular.
    Uranus and Pluto are too inclined.
    The desinclination of Venus and of Jupiter causes that they haven´t got seasons.
    And Neptune, Saturn , Mars and the Earth has got seasons.

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  18. Alberto Garcia Paula25 de noviembre de 2015, 13:43

    The Earth Mars Saturno Neptuno and Pluto others are not so inclined or are not inclined

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  19. Miguel Rodriguez Belmonte29 de noviembre de 2015, 11:20

    I think the planets with seasons are the earth,mars,neptune and saturn becoese it axis are inclined about 20 or 30 degrees

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  20. I think the earth, mars, saturn and neptune has got seasons because they are inclined.

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  21. Candela del Castillo3 de diciembre de 2015, 2:36

    I think the planets have seasons are
    - Earth
    - Saturn
    - Neptune
    - Mars
    Because has got the same grade of rotation

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  22. the earth,satun,neptune and mars

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  23. Lula Candela Scanavino Prieto13 de diciembre de 2015, 9:52

    The Earth, Mars, Saturn and Neptune have got seasons because their axis are inclined so they can receive the sun's rays with different intensity. Mercury, Jupiter, Uranus, Pluto and Venus haven't got seasons.

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