Looking at the earth in the distant deep space is also a star in the sky? There will be how bright?

On a clear night, looking up at the starry sky, the stars shine, and many people are full of reverie. So, what does the earth look like if we are on these planets? Will it be a star? It has how bright? Now let's find out the answer.

Yes, the earth is also a very bright star from the surrounding planets.

In the night sky, humans can see more than 6,000 stars, but most of them are stars, and only a few are planets in the solar system. Stars are very big and glow by themselves, so we can see them from far away. Planets and stars are not an order of magnitude at all. They don't emit light by themselves, but reflect the light of the stars. Only when they are very close will they be seen by us.

The planets we can see with the naked eye are Venus, Jupiter, Mars, Mercury and Saturn in terms of brightness, among which Mercury is often hidden in the sunlight because it is too close to the sun, so it is difficult to see.

Venus is the brightest star in the whole day except the moon at night. This is because Venus is the closest planet to us, about the size of the Earth. Venus can reach -4.6 at its brightest. This? Wait? It is the apparent magnitude, which is the standard for the naked eye to see the brightness of stars. Apparent magnitude means that the smaller the value, the greater the brightness, the greater the value, the smaller the brightness, and the more negative and brighter it is.

The maximum resolution of human eyes can only reach about 6 stars, which is why people with the best eyesight can distinguish the darkest stars. Look at the darkest stars when there is no light pollution, the atmosphere is quiet and there is no moonlight at night. Nowadays, the lights are dim everywhere in the city, and when there is frequent air pollution, there are very few stars that can be seen, and there are dozens of the brightest stars in the sky that can often be seen. Even in the dark countryside or Shan Ye, it is good to see a 5-magnitude star.

From the position of nearby planets, can there be how bright on the earth?

The diameter of the earth is 12756km, and Venus is 12 103.6km, which is about 5.4% larger than Venus, but the atmospheric density of the earth is not as big as Venus, and the ocean occupies 70% of the earth's surface, so the comprehensive reflectivity of the earth is about 35~45%. On the other hand, Venus is surrounded by a thick atmosphere with a reflectivity of 76%.

Reflectivity is the percentage of radiation energy reflected by an object to the total radiation energy, which means how much of the total radiation energy irradiated by the sun on the planet is reflected back into space. So generally speaking, planets with high reflectivity look brighter. However, because the planet revolves around the sun, with the distance from the sun and the angle of the sun shining on the planet changing, the brightness of the planet seen by human eyes will change greatly in different years and at different times.

According to these data conditions, although the earth is a little bigger than Venus, it may not be as bright as Venus, because the reflectivity of the earth is smaller than Venus and the distance from the sun is farther than Venus, so the illumination intensity obtained is not as big as Venus. But from Venus, the earth is still the brightest star in the night sky, with an apparent magnitude of about -4. You can also see the moon, the brightness is above -2, which is worse than Mercury.

Looking at the earth on Mars, the earth is definitely the brightest star in the night sky, and even the moon is very bright, perhaps second only to Jupiter. But in Jupiter's position, about 780 million kilometers away from the earth, the earth you see is already an ordinary star with a brightness of only about 4 stars.

The starlight of the earth reaches farthest.

The apparent magnitude of Saturn seen by humans on earth is about -0.4~ 1.3, etc. And it is a very bright star. This is because Saturn is very big, with a diameter of about 9.5 times that of the Earth and a volume of more than 830 times that of the Earth. However, the nearest time is about 65.438+0.28 billion kilometers from the earth, and the farthest time is about 65.438+0.57 billion kilometers from the earth. The earth is much smaller than Saturn, so even at the best angle and distance, the earth and the apparent star are close to the resolution limit of the naked eye, that is, about 5 stars, which requires good eyesight to distinguish.

This is because the earth is much closer to the sun than Saturn, and the intensity of sunlight received is much greater than Saturn, so it is brighter. You can't see the earth if you go any further. Uranus is four times the diameter of the earth and more than 60 times the volume of the earth, but because it is too far away from the sun and the earth, the apparent magnitude is only about 6, so it is difficult for us to see Uranus on the earth. The earth is much smaller than Uranus, and even if it is close to the sun, the reflected sunlight is very strong, which is far from being seen.

The farthest starlight photo of the earth.

Man now has a real picture farthest from the earth, which was taken by navigator 1 in February 1990. Looking back, it is 6.4 billion kilometers away from the earth. In this place, the light and shadow of the earth is only 0. 12 pixels. The star of the earth has been completely submerged in the cosmic dust, which is completely indistinguishable to the naked eye. The photo we saw was a faint bright spot after being magnified several times.

This famous photo shocked mankind. You know, there are 7 billion people living on this tiny pixel of 0. 12, which is not even as small as a grain of dust. These humans are spying on the stars and giving birth to all kinds of fantasies. It's really scary to think about it.

The radius of the solar system is at least 1 light-year, and 6.4 billion kilometers is only one third of the radius of the solar system. Further, the earth will disappear completely. The solar system is just one of about 400 billion stars in the Milky Way. The radius of Hubble volume is 46.5 billion light years, and there may be 10 trillion galaxies, as well as Hubble volume.

The earth is a dusty starlight floating in the universe and can only be seen in a very small space. How small is the earth and how small are humans? Now you know. Thank you for reading and welcome to discuss.

Spreading original copyright in time and space, infringement and plagiarism are immoral behaviors, please understand and cooperate.