What if Mars was more like Earth?

A year on Earth, Mars and other planets

A year on earth lasts 365 days and a day has 24 hours. Would the year be the same if we lived on Mars or Saturn? And are there seasons there too?

The movements of the earth

The sun determines the measurement of time on earth: from days to months to years. Our clocks are set according to the rhythm of light and dark. But how intensely and for how long the sun shines on earth depends on the movements of the earth. The duration of a day and the duration of a year are influenced by two different movements.

Earth's rotation - day and night

The earth rotates like a top around its own axis, which can be imagined as a rod that protrudes vertically at the north and south poles. This so-called earth rotation lasts 24 hours and is responsible for the change between day and night. It is day on the side of the earth facing the sun. On the other hand, it is night at the same time.

Earth Revolution - Seasons

But the earth also moves around the sun (this movement is called the earth revolution). Their orbit is about 150 million kilometers from the sun. The earth needs about 365 days, i.e. a year, for a complete orbit around the sun. The orbit is slightly oval (elliptical); therefore the earth is not always exactly equidistant from the sun.

But that does not explain why we experience spring, summer, autumn and winter on earth. To do this, one must note that the earth's axis is inclined relative to the orbit. If the northern hemisphere of the earth is inclined towards the sun, the sun's rays hit there at a steeper angle (the sun is high in the sky at noon) and more than half of the hemisphere is illuminated by the sun (the days are longer than the nights ): The northern hemisphere is warming up more than the southern hemisphere - it's summer here.

After half a year, when the earth is on the opposite side of its orbit, the southern hemisphere is tilted towards the sun. The northern hemisphere is then touched by the sun's rays at a shallower angle and less warmed - it is winter. Between these two extreme situations we experience spring and autumn respectively.

An animation of this explanation can be found in this video from TheSimpleGeography.

The year on other planets

There are eight planets in our solar system that orbit the sun. Closest to the sun is Mercury, then come Venus, Earth, Mars, Jupiter, Saturn, Uranus and finally Neptune. Neptune is about thirty times further from the sun than the earth. The greater the distance from the sun, the greater the circle that Neptune must draw around the sun.

In addition, the planets that are closer to the sun are more strongly attracted by their gravity. This attraction accelerates the planets and makes them orbit faster (the earth, for example, races around the sun at 107,208 kilometers per hour - a hundred times faster than an airplane). So Neptune moves more slowly than the other planets and has to cover a longer distance. A year on Neptune, i.e. a complete revolution around the sun, lasts almost 165 earth years or 60,148 days! Information on the other planets can be found in the table below.

You can find great pictures of stars and space in our gallery.

The day on other planets

The rotation of a planet, which determines the length of the day, depends on several factors: the composition of the planet, collisions with other objects during its lifetime or the original speed that the planet got when it was formed.

While the days on Mars are about the same length as on Earth, the days on Jupiter, Saturn, Uranus and Neptune are slightly shorter - between 10 and 17 hours. One day on Mercury is about 58 days on Earth.

But that is nothing compared to Venus. It takes 243 days to rotate around its own axis! That is even longer than the time it takes to circle the sun once, namely 225 days. That means that a day on Venus lasts longer than a year. crazy, is not it?

The seasons on other planets

The inclination of the axis is also different for the planets. The axis of our neighbor Mars is similarly inclined as the Earth's axis, therefore there are four seasons there too. Mercury, Venus and Jupiter have only very weakly inclined axes and do not experience any seasons. Uranus, on the other hand, has extreme seasons due to the steep inclination of its axis. It is therefore dark at its poles for 42 years and then light again for 42 years, while this rhythm lasts half a year on earth.

Comparison of the planets in our solar system

planet

Distance to the sun (million km)

Orbit time around the sun (earth days)

Speed ​​around the sun (km / h)

Length of a day (earth days)

Inclination of the earth's axis

Mercury

58

88

172'332

58 days 15 h 36 min

Venus

108

225

126'072

243 days 27 min

earth

150

365

107'208

23 h 56 min = 1 day

23,5°

Mars

228

687

86'868

1 day 37 min

25°

Jupiter

778

4,329 (11 years, 314 days)

47'052

9 h 55 min

Saturn

1'433

10,751 (29 years, 166 days)

34'884

10 h 47 min

27°

Uranus

2'872

30,664 (84 years, 4 days)

24'516

17 h 14 min

98°

Neptune

4495

60,148 (164 years, 288 days)

19'548

15 h 58 min

30°

Source: https://astrokramkiste.de/planeten-tabelle and http://www.goerlitzer-sternfreunde.de/html/jahreszeiten.html