What is Aphelion?
- July 6, 2024
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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What is Aphelion?
Sub: Science and tech
Sec: Space sector
Context:
- Earth had reached aphelion on 5th July which is the farthest distance from the Sun.
About Aphelion:
- Aphelion, in astronomy, the point in the orbit of a planet, comet, or other body most distant from the Sun.
- When Earth is at its aphelion in early July, it is about 4,800,000 km farther from the Sun.
- Earth reaches aphelion every July.
- That Earth has an aphelion is a result of its orbit being elliptical, rather than circular.
- All planets in the solar system travel in elongated circles around the Sun, rather than perfect ones.
- Jupiter exerts the most influence because it is the most massive planet in our solar system.
- The higher the eccentricity, the more elliptical the orbit (Earth’s eccentricity is 0.017).
How far is the Earth from the Sun at aphelion?
- Aphelion refers to the point in Earth’s orbit when it is farthest from the Sun, occurring around July 4 each year.
- At aphelion, Earth’s distance from the Sun is about 152.1 million km.
- On January 3rd, Earth is closest to the sun and the distance is around 147.5 million Kilometers. This is called Perihelion.
Does aphelion affect temperatures on Earth?
- A common misconception is that Earth’s varying distance from the Sun is what gives rise to the seasons.
- We get 7% less sunlight at aphelion compared to what we are exposed to at perihelion, leading to slightly milder summers and winters in the Northern Hemisphere.
- This effect is offset by Earth’s tilt on its axis at different points along its orbit.
What would happen if there were no aphelion?
- If our planetary orbit were a perfect circle, the seasons’ lengths would be exactly the same.
- Currently, spring and summer are a few days longer than fall and winter in the Northern Hemisphere. But not much else would change.
- But if something made Earth’s orbit grow more eccentric, the consequences could be catastrophic.
- Seasons in the Southern Hemisphere would become too extreme — summers would be unbearably hot, and winters would be intolerably cold.
- This could lead to crop failures and freezes.
What is Perihelion:
- The term “perihelion” refers to the point in the orbit of a planet or other astronomical body, at which it is closest to the sun.
- The word comes from Greek and literally means around (peri) the sun (helios).