「最も深遠な宇宙画像」公開へ　ウェッブ望遠鏡で撮影　ＮＡＳＡ

【ワシントンＡＦＰ＝時事】米航空宇宙局（ＮＡＳＡ）のビル・ネルソン長官は６月２９日、新たに運用が開始されたジェームズ・ウェッブ宇宙望遠鏡による「これまでに撮影された最も深遠な宇宙の画像」を今月１２日に公開すると発表した。（写真はジェームズ・ウェッブ宇宙望遠鏡のイメージ図）
　ネルソン長官は会見で「人類がこれまでに目にしたことのある範囲よりもさらに遠くだ」と述べた。１００億ドル（約１兆３５００億円）を費やして製造されたウェッブ宇宙望遠鏡は、昨年１２月に打ち上げられ、現在は地球から約１５０万キロ離れた軌道で太陽を周回している。
　工学技術の粋を集めたウェッブ宇宙望遠鏡は、口径６．５メートルの巨大な主鏡と、塵（ちり、固体微粒子）やガスを透過できる赤外線に特化した観測機器を備えており、これまでのどの望遠鏡よりも遠くまで宇宙を観測することができる。
　「太陽系内の天体や、太陽以外の恒星を周回する系外惑星の大気を調査する予定だ。系外惑星の大気が地球の大気と類似している可能性があるのかという問いへの手掛かりが得られる」と、ネルソン長官は続けた。
　「現在ある疑問のいくつかに答えを出せるかもしれない。われわれはどこから来たのか、宇宙には他に何かいるのか、われわれは何者なのかといった疑問だ。そして、まだ存在すらしていない未来の疑問への答えも提供してくれるだろう」
　ウェッブ宇宙望遠鏡の赤外線観測機能は、１３８億年前に起きたビッグバンへ向かって時間の流れをさらに遠くまでさかのぼる観測を可能にする。
　宇宙は膨張しているため、最初期の恒星からの光は、放射された際の紫外・可視光波長から、より長い赤外線波長へと変化する。ウェッブ宇宙望遠鏡はこの赤外光を、かつてない高分解能で検出する機能を備えている。
　現在観測できる最も初期の宇宙は、ビッグバンから約３億３０００万年後のものだが、ウェッブの観測能力はこの記録を容易に打ち破ると天文学者らは考えている。
　ＮＡＳＡは、ウェッブ宇宙望遠鏡による初の系外惑星の分光観測結果も同じく１２日に公表する意向だ。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2022/07/04-14:01）

NASA administrator Bill Nelson said Wednesday the agency will reveal the deepest image of our Universe that has ever been taken on July 12, thanks to the newly operational James Webb Space Telescope.
If you think about that, this is farther than humanity has ever looked before, Nelson said during a press briefing at the Space Telescope Science Institute in Baltimore, the operations center for the $10 billion observatory that was launched in December last year and is now orbiting the Sun a million miles (1.5 million kilometers) away from Earth.
A wonder of engineering, Webb is able to gaze further into the cosmos than any telescope before it, thanks to its enormous primary mirror and its instruments that focus on infrared, allowing it to peer through dust and gas.
It's going to explore objects in the solar system and atmospheres of exoplanets orbiting other stars, giving us clues as to whether potentially their atmospheres are similar to our own, added Nelson, speaking via phone while isolating with Covid.
It may answer some questions that we have: Where do we come from? What more is out there? Who are we? And of course, it's going to answer some questions that we don't even know what the questions are.
Webb's infrared capabilities allow it to see deeper back in time to the Big Bang, which happened 13.8 billion years ago.
Because the Universe is expanding, light from the earliest stars shifts from the ultraviolet and visible wavelengths it was emitted in, to longer infrared wavelengths -- which Webb is equipped to detect at an unprecedented resolution.
At present, the earliest cosmological observations date to within 330 million years of the Big Bang, but with Webb's capacities, astronomers believe they will easily break the record.
- 20 year life -
In more good news, NASA deputy administrator Pam Melroy revealed that, thanks to an efficient launch by NASA's partner Arianespace, the telescope could stay operational for 20 years, double the lifespan that was originally envisaged.
Not only will those 20 years allow us to go deeper into history, and time, but we will go deeper into science because we have the opportunity to learn and grow and make new observations, she said.
NASA also intends to share Webb's first spectroscopy of a faraway planet, known as an exoplanet, on July 12, said NASA's top scientist Thomas Zurbuchen.
Spectroscopy is a tool to analyze the chemical and molecular composition of distant objects and a planetary spectrum can help characterize its atmosphere and other properties such as whether it has water and what its ground is like.
Right from the beginning, we'll look at these worlds out there that keep us awake at night as we look into the starry sky and wonder as we're looking out there, is there life elsewhere? said Zurbuchen.
Nestor Espinoza, as STSI astronomer, told AFP that previous exoplanet spectroscopies carried out using existing instruments were very limited compared to what Webb could do.
It's like being in a room that is very dark and you only have a little pinhole you can look through, he said, of current technology. Now, with Webb, You've opened a huge window, you can see all the little details.