✔ 最佳答案
1. Sun is star, Earth is planet
2. Nuclear fusion at core is the energy source of Sun. Hydrogen becomes Helium and huge amount of energy is released. There is no such nuclear process at Earth.
Sun Statistics
Mass (kg) 1.989e+30
Mass (Earth = 1) 332,830
Equatorial radius (km) 695,000
Equatorial radius (Earth = 1) 108.97
Mean density (gm/cm^3) 1.410
Rotational period (days) 25-36*
Escape velocity (km/sec) 618.02
Luminosity (ergs/sec) 3.827e33
Magnitude (Vo) -26.8
Mean surface temperature 6,000°C
Age (billion years) 4.5
Earth Statistics
Mass (kg) 5.976e+24
Mass (Earth = 1) 1.0000e+00
Equatorial radius (km) 6,378.14
Equatorial radius (Earth = 1) 1.0000e+00
Mean density (gm/cm^3) 5.515
Mean distance from the Sun (km) 149,600,000
Mean distance from the Sun (Earth = 1) 1.0000
Rotational period (days) 0.99727
Rotational period (hours) 23.9345
Orbital period (days) 365.256
Mean orbital velocity (km/sec) 29.79
Orbital eccentricity 0.0167
Tilt of axis (degrees) 23.45
Orbital inclination (degrees) 0.000
Equatorial escape velocity (km/sec) 11.18
Equatorial surface gravity (m/sec^2) 9.78
Visual geometric albedo 0.37
Mean surface temperature 15°C
Atmospheric pressure (bars) 1.013