Average distance between Sun and the Earth gets bigger as time goes on. What are the reasons for this situation? Should we be worried?
According to NASA, the distance between the Sun and the Earth is 150 million kilometers, but the orbit of the star is not perfectly round, but slightly elliptical or oval. Thus, it can vary from 147.1 million to 152.1 million kilometers.
At present, the star king will be moving away from our planet. There are two specific reasons, according to scientists cited living science, in a note written Charles K. Choi:
- The sun is losing mass.
- Forces that cause tides on Earth.
Reasons for the removal of the Sun from the Earth
Brian DiGiorgio, an astronomer at the University of California, explains that because the Sun is constantly producing energy, it is also constantly losing mass.
Models of the evolution of stars over time predict that the Sun will lose about 0.1% of its total mass before it begins to die.
“That’s a lot of money,” DiGiorgio says. “It has about the same mass as Jupiter.”
The astronomer indicates that our planet is moving away from the star by about 6 centimeters per year. “This is quite insignificant, especially compared to the normal variation in the Earth’s orbital distance, which is due to its slightly elliptical orbit, about 3%,” emphasizes DiGiorgio.
In the case of tides on Earth, just as the gravitational pull of the Moon causes tides on our planet, its gravity pulls on the Sun.
Britt ScharringhausenBeloit College in Wisconsin, points out that this is why the side of the Sun facing Earth is stretched, resulting in a “tidal bulge.”
However, tidal forces have very little effect on the orbit of our planet: For this reason, the earth is removed by hardly 0.0003 centimeters per year.
Should we be worried?
The further our planet moves away from the star, the more the climate changes. According to DiGiorgio, “as the Earth moves away from the Sun, the light of the star becomes dimmer (…) This dimming corresponds to a 0.4% reduction in solar energy reaching our surface.”
However, a University of California astronomer elaborates: “This is relatively small compared to the normal variations in the Sun’s brightness due to the Earth’s elliptical orbit.”
Therefore, there is nothing to worry about. At least in the near future.
More changes will be seen in the next 5 billion years, as by this time Despite the greater distance from our planet, the brightness of the Sun will increase, slowly raising the temperature of the Earth, which directly affects the oceans.
“Models of stellar evolution predict that (the Sun) will increase its brightness by about 6% every billion years,” the astronomer emphasizes. “This will make the Earth uninhabitable for humans long before the Sun consumes it.”