According to which biological clocks would life have run if it had originated on one of the other planets or on one of the large moons in the solar system
Since ancient times, the moon has been an enigma and a source of inspiration for the inhabitants of the earth. Recently it became clear that we also owe space to the fact of our existence on the globe. The moon's gravity enabled the formation of huge primordial pools of water, in which, apparently, the conditions for the formation of primary life on Earth developed.
Beyond that, the moon is also the one that maintains the stability of the inclination of the earth's rotation axis in space. Two American researchers from the University of Pennsylvania found that if it weren't for the moon, the Earth would be like Uranus - tilted on its side. Such a tendency would have an extreme effect on the earth's climate, explains the researcher Haim Mazar from the Israeli Astronomical Society In an article he published in the magazine "Astronomy", published by the association. According to him, in such a situation the temperature at the North Pole would reach up to 50 degrees Celsius, and at the South Pole - up to 80 degrees Celsius below zero.
As we know, the reason for the seasons is the inclination of the ball's axis of rotation around itself relative to the plane of its rotation around the sun. The stability of this angle prevents extreme changes in the earth's temperature, changes that would harm the possibility of the development of life. In his article, Mazer tries to speculate what would have happened if life had originated instead on Earth - on one of the other planets or on the other large moons in the solar system. The examination of the biological clock (a clock derived from the tilt of the axis of rotation), writes Mazar, shows that it is of great importance for the existence of life on Earth, and as a result, on other planets as well.
Its influence is felt in the behavior of animals, in their metabolism, in the process of photosynthesis in plants and in the timing of the fall of the leaves. In the animal world, the connection between activity or inactivity of animals and sunlight is known. There are animals that are active during the day and animals that are active at night. Similar phenomena are known in the plant world. On Earth, Mazar explains, there are three biological-astronomical clocks that are defined according to the length of their cycle. One cycle is the day - the dominant cycle in animal nutrition and plant photosynthesis; The middle cycle is this year. It mainly determines the mating dates for animals - and this is coordinated so that the females are born in the spring - and the dates for the fall of the leaves, the flowering and the appearance of the fruits, according to the lengthening or shortening of the days.
The other cycle is the long cycle: with the cicadas, for example, 13 or 17 years pass between egg laying and the development of the complete adult, and the bamboo plants in the Himalayas bloom once every fifty years. The solar system has planets and moons whose day is longer or shorter than the day on Earth. On Mars - 24.5 hours, on Callisto (one of Jupiter's moons) - 16 Earth days, and on Triton (Neptune's moon) - 5.8 days. Theoretically, the longer the day, the more hours of activity the animals will have, and the more hours of photosynthesis for the plants. In a fictional world where all the planets were inhabited by animals (carnivores and vegetarians), the new conditions would have dictated such processes: the carnivorous animals would have had more daylight hours of activity in the long day, and because of that they could have slowed down their running pace in search of prey. But it must also be taken into account that on a longer day they would have dined several times more.
How will the reptiles behave in worlds where the day is long, and therefore the night is also long? Will they be able to exist for so long without movement? And will the birds, under the conditions of a long day, be able to fly tens and hundreds of hours without respite? Additional questions can be posed: If there were life on Mars, a planet where the length of the year is twice that of Earth - would the length of pregnancy of animals be adjusted throughout the winter season? In such a case, the gestation periods of the animals were doubled. But it is possible that under the new conditions the mating would have been closer to the end of winter, and the pregnancy would not have been extended anyway.
In worlds such as the planets Uranus and Pluto, whose angle of inclination is close to 90 degrees, it is possible to imagine permanent climate zones at every latitude and constant day length all year round. Mazar estimates that animals and plants in such worlds will have to rely on an annual cycle.
In a world that has more than one moon, different series of animals and plants must be taken into account, which will exist side by side and behave according to different lunar clocks. Mazar suggests using computer simulations to check the connection between the biological clocks and the constellations.
* Published in Haaretz newspaper.
