“Traces” visible in the celestial bodies of the solar system 14:43, June 17

The circular depressions that can be seen on the moon and planets are the terrain and craters created by the collision of meteorites. I had a problem with the crater in the entrance examination for Difficult Middle School. Let's solve it together.

Challenge difficult entrance exams for junior high school!

Issue
"the most appropriate thing as a statement that described in connection with the crater, select from the following A-d, please answer with a symbol."
A. On the Moon, there are fewer craters on the surface than it was in the old days.
I. Looking at the Earth from space, there are more craters than the Moon.
C. On Earth, the craters that have formed do not disappear.
D. Humans have hit the celestial bodies other than the earth and made artificial craters.

It's a little difficult problem, so let's look at each option one by one.

"A. There are fewer craters on the Moon than on old-fashioned surfaces."
This is a mistake.
It seems that collisions of celestial bodies are always occurring on the time scale of the solar system. If you are exposed to outer space for a long time, many crater marks (craters) will remain.

"A. There are more craters when you see the earth from space than there are from the moon." When
you compare the photo of the moon and the photo of the earth taken from space, it is clear that the earth has fewer craters. ..
This is also a mistake.

“U. On the earth, the formed craters will not disappear and disappear.” In
addition to the terrain changing rapidly due to weathering caused by rain and wind and seawater, the continent moved and eventually dived underground. So almost no old age surface remains. Except for the recently created craters on Earth, the craters have disappeared.
So this is also wrong.

So the correct answer is

"D. Humans have hit objects against celestial bodies other than the earth to create artificial craters."

Will be.

This was accomplished by the Japanese asteroid explorer "Hayabusa 2". Creating an artificial crater on an asteroid was the world's first achievement. You heard about it in the news last April.
By the way, June 13 is just 10 years after the return of the first Hayabusa. In Sagamihara City, where JAXA's research facilities are located, it is called "Hayabusa Day."

Results of "Hayabusa 2" artificial crater

Hayabusa2 aimed at the asteroid Ryugu between the Earth and Mars. An artificial crater was created to collect the substance in the basement of Ryugu. I am currently returning to Earth to bring back a sample of Ryugu. So why did it have to be an underground substance in Ryugu? We spoke with Makoto Yoshikawa, JAXA “Hayabusa 2” Project Mission Manager.

Mr. Yoshikawa
"Since the surface is exposed to the sun's rays and radiation, it is thought that the material has been significantly altered. Simply think that it is a tan. Underground things are not tan. There is a possibility that there is a possibility that the material has not been altered and is closer to the original material.I think that it can be investigated in various ways by comparing the surface material and the underground material. It is an organic substance in Ryugu. Life is made of organic matter, but it is basically carbon, such as protein and fat. Originally, we are searching for a substance containing carbon.”

At least, without carbon, no earth-like life will be born.

The "source of life" of "Ryugu"

Yoshikawa and his colleagues used Hayabusa2 to search the asteroid Ryugu for substances that were the source of life on Earth. So why did it have to be the asteroid Ryugu?

Mr. Yoshikawa: The
material that becomes the life must have been 4.6 billion years before the birth of the solar system. However, there is no material left on the planet like the earth in the old days. It's been said that they haven't done it, so there may be the material that gave it life. It's about looking for it."

The substance that made life alive...is it in Ryugu?

Mr. Yoshikawa: From
the ground observation, it was known that carbonaceous substances seemed to exist in Ryugu, and actually Ryugu has a very dark color. I think this is probably due to carbon. I hope there is organic matter in that.''

Expectations for Hayabusa2

"Hayabusa 2" on the way back to Earth. If all goes well, he will return at the end of the year.

Mr. Yoshikawa:
First of all, it means to properly return the capsule to the earth, but I am paying close attention to what kind of substance is contained in the capsule. Furthermore, now, there are nearly 1 million asteroids found. There are many possibilities, so I'm happy to have information that will lead to such future missions.''

In “Weekly Marukai News” (Broadcast on Saturday at 9 am), “Migake, Curiosity!” delves into the news every week, focusing on current affairs and other issues raised during the entrance examination.
Let's think of "Why?"