The astrophysicist explained whether seasonal changes occur on other planets and how this differs from what happens on Earth.
Spring, summer, autumn and winter are seasons that change every few months on Earth, around the same time each year. IFLScience writes that people may accept this cycle as it is, but such a change in seasons is not observed on every planet.
In the new study, Georgia Tech physics professor Gongjie Li focused on understanding why Earth has regular seasons while other planets do not.
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During his research, the scientist discovered that the regular change of seasons on Earth is unique: the axis of rotation of our planet along the North and South Poles is not completely different from the vertical axis perpendicular to the Earth’s orbit around the sun. According to the astrophysicist, it’s this slight tilt that has the biggest impact on everything from seasons to ice sheets. Moreover, the scientist believes that this value is what determines how suitable the planet is for life.
Seasons on Earth
When a planet has perfect alignment between the axis on which it rotates and its axis of rotation, the amount of sunlight it receives throughout its orbit around the Sun remains constant. Seasons are caused by differences in the amount of sunlight reaching the planet’s surface. Simply put, a perfectly aligned planet would have no seasons. But the Earth is not like that; Our planet is not perfectly aligned on its axis.
This slight tilt of 23 degrees relative to the Earth’s vertical is actually responsible for the changing seasons on our planet. As a result, the Northern Hemisphere is exposed to intense sunlight during the summer months when the Sun is directly over the Northern Hemisphere. As the Earth rotates around the Sun, the amount of sunlight the Northern Hemisphere receives gradually decreases as the Northern Hemisphere moves away from the Sun. Winter is coming now.
How do changes in slope affect the seasons?
The lower tilt means the axis of rotation matches the planet’s orbit around the sun, leading to stronger sunlight at the equator and less sunlight near the pole, Lee said. This is exactly what happens on Earth.
However, a large tilt in which the planet’s rotation axis is pointed toward or away from the Sun will cause the poles to become extremely hot or cold. At the same time, the equator cools down because the sun’s rays do not reach here all year round. All this will lead to a sharp change of seasons in high latitudes and low temperatures at the equator.
If the planet’s tilt exceeds 54 degrees, the planet’s equator will be covered in ice and its pole will warm up. According to Lee, this is called reverse zoning and is the exact opposite of what happens on Earth. The astrophysicist also believes that a sudden and strong change in tilt angle could actually turn the planet into an ice-covered snowball.
Spin-orbit resonances
Most planets are not alone in their solar systems, and so their planetary siblings can disrupt each other’s orbits, leading to changes in the shape and inclinations of their orbits.
According to Lee, orbiting planets can be compared to the rotating ceilings on the roof of a car that is being shaken along the road. Moreover, in this case the car represents an orbital plane. When the rotation speed of the upper parts matches the shaking frequency of the “car”, something called spin-orbit resonance occurs.
Spin-orbit resonances can cause these tilt changes as the planet wobbles on its axis. For example, Mars oscillates more around its axis than Earth, even though they have approximately the same angle of inclination. According to Lee, this is explained by the Moon’s rotation around the Earth.
The fact is that Earth and Mars have the same rotational precession frequency, which corresponds to orbital wobbles, but our planet has a huge satellite that helps pull the Earth’s rotation axis, thus causing it to precess faster. In simple words, it is the Moon that stabilizes the tilt of the Earth, and therefore our planet does not oscillate around its axis as much as Mars does.
Seasons on other planets
Over the past few decades, scientists have discovered thousands of exoplanets, or planets, beyond our solar system. In their study, Lee and his team wanted to understand how habitable these planets were and whether they had sharp tilts or moons that would help with their stability.
In the research, scientists examined Kepler-186f, the first Earth-sized planet discovered to be in the habitable zone. Scientists have found that it has only a weak influence on the orbit and movement of other planets.
Study results show that Kepler-186f has a constant tilt, just like the Earth. Even though it’s not a large moon, Mars doesn’t have wildly changing or unpredictable seasons. In the future, scientists plan to continue research to understand what the seasons look like on other planets in the Universe.
Previously Focus He wrote about how the seasons change on a planet where the year lasts only 3 days.
Source: Focus
Ashley Fitzgerald is an accomplished journalist in the field of technology. She currently works as a writer at 24 news breaker. With a deep understanding of the latest technology developments, Ashley’s writing provides readers with insightful analysis and unique perspectives on the industry.