Six Types of Sugars Detected in Asteroid Sand Brought Back by NASA Probe

Recently NHK News on-line reported the following:

NASAの探査機が持ち帰った小惑星の砂から6種類の糖を検出

2025年12月2日午後7時02分

宇宙

NASA＝アメリカ航空宇宙局の探査機が地球に持ち帰った小惑星の砂から6種類の糖を検出したと、日本などの国際研究グループが発表しました。見つかった糖のうち「リボース」はRNAを構成する分子で、研究グループは、宇宙に生命の材料となる糖が存在し、地球に降り注いでいたことを示す結果だとしています。

日本とアメリカの国際研究グループは、NASAの探査機が太陽系の小惑星「ベンヌ」から地球に持ち帰った砂などのサンプルのうちおよそ0.6グラムを分析し、6種類の糖を検出しました。

このうち、「リボース」は遺伝情報を伝えるRNAを構成する分子で、「グルコース」は生命のエネルギー源となる分子として知られています。

研究グループによりますと、この小惑星のサンプルからは、これまでに、たんぱく質の材料になる「アミノ酸」や、DNAとRNAに使われる5種類の「核酸塩基」が検出されていましたが、糖が検出されたのは初めてです。

一方で、こうした糖の一部は地球上に落下した隕石（いんせき）からも検出された例があります。 

こうしたことから研究グループは、宇宙に生命の材料となる物質が存在し、それらが隕石によって地球にもたらされたという仮説を強く裏付ける結果だとしています。

研究グループの東北大学大学院理学研究科の古川善博准教授は「宇宙から生命の材料が来ていたことがより確実になった。宇宙から来た材料で生命ができたのか、地球での化学反応で生命の材料ができたのかはまだ分からず、さらに研究していきたい」と話しています。

「生命の起源」の元となる物質は宇宙から？それとも地球？

「生命の起源」の元となる物質が宇宙から来たのか、それとも地球でできたのかは、今も議論が続いています。

惑星科学に詳しい東京科学大学地球生命研究所の関根康人教授は、「地球外から来た材料物質が生命の誕生にどれぐらい寄与したのかは現時点ではっきりとは分からない」としています。

関根教授によりますと、生命の起源の元となる物質が原始の地球にどれくらいあったのかは当時の大気の化学組成によって大きく変わってくるということです。

大気の組成が生命の材料物質ができるのに適さなかった場合は、隕石などによる地球外からの材料物質の供給が相対的に重要になるとしています。

関根教授は小惑星のサンプルから糖を検出した今回の研究成果について、「われわれの生命の元となるもののでき方、生命のレシピを明らかにする研究をこれからやる必要がある」と話していました。

Translation

Six Types of Sugars Detected in Asteroid Sand Brought Back by NASA Probe

An international research group, including researchers from Japan, announced that they had detected six types of sugars in asteroid sand brought back to Earth by a NASA = National Aeronautics and Space Administration probe. Among the sugars found was ribose which was a molecule that made up RNA. The research group believed this result indicated that sugars, the building blocks of life, existed in space and had rained down to Earth.

An international research group from Japan and the United States analyzed approximately 0.6 grams of sand and other samples brought back to Earth by a NASA probe from the solar system asteroid Bennu and detected six types of sugars.

Of these, ribose was a molecule that makes up RNA, which transmitted genetic information, and glucose was known as a molecule that served as an energy source for life.

According to the research group, amino acids, the building blocks of proteins, and five types of “nucleic acid bases” used in DNA and RNA had previously been detected in this asteroid sample, but this was the first time that sugars was detected.

However, there were incidents that some of these sugars had also been detected in meteorites that fell to Earth.

The research group stated that these results strongly supported the hypothesis that materials that could lead to life had existed in space and were brought to Earth by meteorites.

Associate Professor Yoshihiro Furukawa (古川善博) of the Tohoku University Graduate School of Science and member of the research group, said, "We are now more certain that the materials for life came from space. We still don't know whether life was created from materials that came from space, or whether the materials for life were created through chemical reactions on Earth, so we would like to conduct further research."

Did the material that formed the origin of life come from space? Or Earth?

Debate continued as to whether the material that formed “the origin of life” came from space or was created on Earth.

Professor Yasuto Sekine (関根康人) of the Earth-Life Science Institute at Tokyo University of Science, who specialized in planetary science, said, "At this point, we cannot clearly determine to what extent materials that came from outside Earth contributed to the birth of life."

According to Professor Sekine, the amount of material that could be the origin of life appeared on primordial Earth depended greatly on the chemical composition of the atmosphere at the time.

If the composition of the atmosphere was not suitable for the formation of the materials for life, then the supply of materials from outside the Earth, such as through meteorites, would become relatively important.

Regarding the results of this research, which detected sugars in asteroid samples, Professor Sekine said, "We need to continue research to uncover how the materials that gave us life are formed, and the recipe for life."

              So, an international research group has announced that they detect six types of sugars in asteroid sand brought back to Earth by NASA. Among the sugars found is ribose which is a molecule that made up RNA. The research group believes this result indicated that sugars, the building blocks of life, all along has existed in space and may have rained down to Earth previously. Apparently, this is an interesting discovery that may help find out whether “the origin of life” came from space or was created on Earth.