How many of the 10 entry-level astronomy knowledge do you know?

In the vast universe,the existence of each celestial body is special,or can be said to be unique.Every celestial body has its own characteristics.Like us humans,celestial bodies have their own properties,such as those that can emit light,those that cannot emit light,those with high gravity and those with low gravity.
First,the real color of the sun is white,not the golden yellow we see every day,because when the light emitted by the sun passes through the atmosphere,the light with shorter wavelength in the visible light is either absorbed by the atmosphere or scattered,leaving only yellow light and some red light.Therefore,the sun in our eyes can only be yellow or the same red as the sunset.If you leave the earth's atmosphere and observe the sun in space,you will find that the natural color of the sun is white.
Second,the planet with the highest surface temperature in the solar system is not mercury,but Venus.Although mercury is closest to the sun,its surface temperature can only reach 427 degrees Celsius during the day.Venus has a dense atmosphere dominated by carbon dioxide,which will cause a strong greenhouse effect.On Venus,its surface temperature can reach more than 500 degrees Celsius and more than 400 degrees Celsius at night,making the average surface temperature of Venus reach more than 400 degrees Celsius.By the way,mercury is the planet with the largest surface temperature difference in the solar system because its nighttime temperature can drop to minus 183 degrees Celsius.The surface temperature difference between day and night is as high as 600 degrees Celsius.Although mercury is closest to the sun,NASA sent it to the mercury probe messenger in 2014 and found ice near a crater at the north pole of mercury.
Third,Venus,the planet that"lives like a year".Venus'revolution cycle is 224.7 Earth days,and its rotation cycle is 243 Earth days,which means that Venus'Day is 18 Earth days older than that.One thing to note is that Venus is the only planet in the solar system that rotates in the opposite direction.The direction of rotation is from east to west,which means that the sun rises in the West and sets in the east from Venus.
Fourth,the distance between the earth and the moon is larger than you think.You can put down the other seven planets in the galaxy.The average distance between the moon and the earth is about 384000 kilometers.This distance is insignificant on the astronomical scale,but at this negligible distance,it is enough to put down the other seven planets in the solar system,which is enough to show how empty our universe is.
Fifth,the sunshine on you may have formed before human history.As we all know,it takes more than 8 minutes for light to travel from the surface of the sun to the earth,but it is a long process for photons generated from the inside of the sun to reach the surface of the sun.Because the sun is a huge plasma mass,when the photons generated in the center of the sun spread outward,countless atomic electrons interact with other charged particles in the sun.Only when they reach the surface of the sun,can it propagate independently at the speed of light.On average,it takes about onemillion years for photons inside the sun to reach the surface of the sun.In other words,the sunshine you see now is probably prehistoric,ancient sunshine.
Sixth,Uranus is lying.We know that the earth's rotation axis has an inclination of about 23 degrees,but Uranus'rotation axis has an inclination of up to 98 degrees,which is nearly parallel to the orbital plane of the sun.,This means that Uranus is lying in motion.Astronomers generally believe that Uranus'current posture is likely to be formed by the collision of a larger planet.Due to the impact of a huge celestial body,its state has changed greatly,forming the current mode of operation.
Seventh,Jupiter is the largest planet in the solar system,which is large enough to serve as our shield and accommodate all other planets in the solar system.Its volume is 1316 times that of the earth,and its mass is 318 times that of the earth.It is also the most massive planet in the solar system.Most importantly,if there was no shelter of Jupiter,the earth would probably have been hit by meteorites and lifeless.
Eighth,the largest known star,shield uy,can hold 4.5 billion Suns or 200million earths.If it is placed in the center of our solar system,the sun,mercury,Venus,Jupiter,Mars and the asteroid belt(including our earth)will only run in its belly,and five of the eight planets will be swallowed by it.Isn't it shocking that it will take more than nine hours to orbit the star at the speed of light?
Ninth,Galaxy merging is not a rare phenomenon.Scientists have found that the Milky way has been annexing other dwarf galaxies.According to a new study,the Milky way has collided with 12 galaxies since its formation billions of years ago.In the past 12billion years,the Milky way has merged with 12 large galaxies and three smaller galaxies.According to scientists'research,about 3billion years later,the Milky way will merge with the nearby Andromeda galaxy M31.I don't know whether the earth will still exist at that time.
Tenth,light year is a unit of distance,not a unit of time.Since the speed of light in vacuum is not limited by inertia and reference system and is constant,human beings use the speed of light as a tool to measure distance.The current accurate measurement of the speed of light is 299792458 meters per second,about 300000 kilometers per second.A light year is the distance of light propagation in a year(365.25 days).The exact distance of a light year is 9460730472580800 meters,about 9.46 trillion kilometers.