I was a fifth-year elementary school student. I belonged to the astronomy club organized by the Nagoya City Science Museum, which offered free access to its planetarium once a month. There I became acquainted with Akiko-chan, who happened to be seated next to me. Then, I began to meet Akiko-chan every month.
After I reclined my seat, a star-studded sky would expand above my head. I really loved that moment. When giving a commentary, a staff member would point to the relevant stars with arrow lines drawn with a ruler, as Greek people in the past had drawn lines between stars and applied myths to the shapes formed by those lines.
“This is Antares, a big star that glows very brightly in Scorpio. The name is easy to remember, as its pronunciation is similar to ‘Anta-dare-desu?’” (meaning “Who are you?”).
The show always went on like that. Time flew really fast in the planetarium.
“I will join NASA!” Akiko-chan suddenly blurted out one day.
I had no idea what she was saying. According to her, NASA was a U.S. space research institute. She was so crazy about the planetarium that she had conducted various research, until she finally found out about the institute.
“Why not go somewhere in Japan?”
“Because the U.S. is more advanced in research. Also, the U.S. has made it to the moon.”
I see.
“What do you need to do to join NASA?”
There, Akiko-chan was lost for words.
“I don’t know. I’ve got to study, which is perhaps the only way,”
she replied without confidence.

Even after the astronomy club activities ended a year later, I continued to join the planetarium’s monthly event together with Akiko-chan. She loved watching reruns of the American SF series Star Trek, which depicts mankind’s voyages to various planets in a spacecraft in the distant future.
“There are many people in space. I want to see them.”
　Akiko-chan was fascinated by space. She bought a lot of astronomy books, and when she entered junior high school, she even got an astronomical telescope. I assume there was nothing she could learn from the planetarium anymore. Still, her admiration for the starry sky in the planetarium did not waver.

In the summer vacation of her third year at junior high school, Akiko-chan’s father died of cancer. I attended his funeral together with my mother. I saw Akiko-chan and her mother shedding tears. Partly because we needed to prepare for entrance examinations for high school, Akiko-chan no longer invited me to go to the planetarium with her. I corresponded with her, but now I know that her father’s funeral was my last opportunity to see her.
After a while, even our correspondence faded away, and we only exchanged New Year’s greeting cards. I sometime looked up at the starry sky and remembered Akiko-chan. I imagined that she was still studying in order to work at NASA.

When I was preparing for my university entrance examinations, I expected that Akiko-chan would surely study in a science course at university to join NASA. In reality, however, she got a job right after graduation from high school. My mother said that it might be difficult for her to go to university because she had lost her father. After all, she did not join NASA. A few years later, she got married as many other women did. I learned about all these things only from the New Years’ greeting cards from her. However, she looked very happy in the picture on the postcard telling me that she had got married, so she was probably happy even though she did not go to NASA.

In November of the year that I turned 50, I received a mourning-notification postcard saying that Akiko-chan had passed away in May. The card was from her husband.
“No way!” I yelled without realizing it.
You’re still 50. You’re too young to die. Akiko-chan, what’s happened to you? You told me that you would go to NASA. If you had lived longer, you might have been able to enjoy a space trip. Tears were rolling down my cheeks. I did not see her for long, but she was still my oldest friend. I hesitated a little while, but I finally called Akiko-chan’s husband by smartphone. She had suffered from cancer. He said that it was too late when the disease was detected.

I went outside, gripping my smartphone tightly. Almost no stars were visible in the urban area. Still, one star was glowing extremely brightly. It was Akiko-chan! She could not go to NASA, but she had become a star. She had nowhere to go other than to space.
“Hey! Akiko-chan!”
I waved my hand at the night sky.

小学五年生だった。名古屋市の科学館が主催の天文クラブに入っていた。一ヶ月に一度、プラネタリウムを無料で見せてくれる。そこで知り合ったのが明子ちゃんだ。席が隣になったのがきっかけ。それから毎月、明子ちゃんと会うようになった。
　リクライニングシートを倒すと、頭上に満面の星空が広がる。その瞬間が大好きだった。プラネタリウムの説明をする係の人は、その昔ギリシャの人が星と星を結んで神話に当てはめたように、定規を当てはめて、矢印マークで星を教えてくれる。
「これが、さそり座のひときわ輝きの大きい星アンタレス。覚え方は、あんた誰です、アンタレス」
　毎度この調子だ。プラネタリウムで過ごす時間はあっという間だった。
「私、ナサに行く！」
　ある日、明子ちゃんが突然言い出した。何のことだかさっぱりわからない。明子ちゃんによると、ＮＡＳＡというアメリカの宇宙研究所らしい。明子ちゃんはプラネタリウムに夢中になるあまり、色々調べて、ＮＡＳＡという存在に到達したのだ。
「なんで日本じゃいけないの」
「だって、アメリカの方が研究が進んでいるんだもの。月にも行ったじゃない」
　なるほど。
「ＮＡＳＡに入るにはどうするの」
　明子ちゃんは、ここで言葉に詰まった。
「わからない。勉強するしかない、と思う」
　自信なさげに明子ちゃんは言った。

　天文クラブは一年で終わったが、明子ちゃんとは毎月のプラネタリウムの催しに通い続けた。明子ちゃんは『宇宙大作戦』というアメリカのＳＦドラマの再放送を観ていた。遙か未来に、人類が宇宙船で色々な星を探訪するというドラマだった。
「宇宙には、沢山の人がいるんだ。会ってみたい」
　明子ちゃんは、陶酔していた。明子ちゃんは、星の本をたくさん買っていたし、中学に入った時に天体望遠鏡まで買って貰った。多分、プラネタリウムには、もう明子ちゃんの勉強することはなかったんじゃないだろうか。でも、プラネタリウムの星空は、明子ちゃんの憧れであり続けた。

中学三年の夏休み。明子ちゃんのお父さんが癌で亡くなった。私は母とお葬式に行った。明子ちゃんとお母さんが泣いていた姿が見えた。受験生でもあったし、それから明子ちゃんにプラネタリウムに誘われることもなくなった。文通はしていたけれど、今思えば、明子ちゃんのお父さんのお葬式が明子ちゃんを見た最後だった。
やがて文通も途絶え、明子ちゃんとは年賀状だけの付き合いになった。時々、星空を見ると明子ちゃんのことを思い出す。きっとＮＡＳＡへ行く勉強を続けているんだろうな。

　大学受験の時、明子ちゃんはＮＡＳＡに行くために理系の大学に行くに違いないと私は思っていた。しかし、実際には高卒で就職した。明子ちゃんの家は母子家庭だから大学進学が難しいのかもね、と私の母は言っていた。その後も、結局ＮＡＳＡへは行かなかった。何年か後に、ごく普通の結婚をした。すべて年賀状の近況で知るのみだった。でも、結婚しました葉書に写っていた明子ちゃんは、とても幸せそうだったから、ＮＡＳＡに行かなくても幸せだったのだろう。

五十路を超えた年の十一月に、一通の喪中葉書が届いた。そこには、明子ちゃんが五月に永眠したとご主人の名前で書いてあった。
「嘘だっ」
思わず、私は叫んだ。まだ五十歳じゃないの。死ぬような年じゃない。明子ちゃん、何があったの。ＮＡＳＡに行くって言ってたじゃない。長生きすれば、宇宙旅行が出来るようになったもしれないのに。私の頬を涙が伝う。長く会っていなくても、明子ちゃんは私の最も古い友達だったのだ。しばらく悩んだが、私は明子ちゃんのご主人にスマホで電話した。癌だった。見つかった時はもう手遅れだったそうだ。

スマホを握りしめたまま外に出る。都会では星はほとんど見られない。でも、ひときわ明るさを放つ星が一つあった。明子ちゃんだ！　明子ちゃんはＮＡＳＡには行けなかったけれど、自分自身がお星様になったんだ。明子ちゃんが行くところは、宇宙しかないもの。
「おーい、明子ちゃん！」
　私は夜空に向かって手を振った。