James Webb: Just starting the telescope – New York Times International Weekly – International

BALTIMORE, Maryland — Until now it has been a feast for the eyes of heaven: the black vastness of space teeming with enigmatic and fathomlessly distant drops of light. Ghostly portraits of Neptune, Jupiter and other neighbors we thought we knew. Nebulas and galaxies visible thanks to the piercing infrared eyes of the James Webb Space Telescope.

The telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency. It was launched Christmas 2021 — after 20 troubled years and $10 billion — on a mission to observe the universe at wavelengths the human eye cannot see. With a primary mirror twenty feet in diameter, Webb is seven times more powerful than its predecessor, the Hubble Space Telescope. An hour of observing time at the telescope can cost NASA $19,000 or more.

But neither NASA nor astronomers paid all that money and political capital just for pretty pictures.

“The first images were just the beginning,” said Nancy Levenson, temporary director of the Space Telescope Science Institute, which operates both Webb and Hubble. “More is needed to turn them into real science.”

In December, some 200 astronomers met at the institute to discuss the first results of the telescope. They described a cosmos of discoveries. Galaxies that, even in their relative youth, had spawned supermassive black holes. Atmospheric studies of some of the seven rocky exoplanets orbiting Trappist 1, a red dwarf star that could host habitable planets. (The data suggests that at least two of the exoplanets lack the bulky hydrogen primordial atmospheres that would choke life as we know it, but could have wispy atmospheres of denser molecules like water or carbon dioxide.)

Perhaps the biggest surprise from the Webb telescope is that in the early millennia of the universe, galaxies appear to have been forming, generating, and nurturing stars faster than older cosmological models estimated.

As the universe expands, galaxies and other distant celestial objects are receding from Earth so fast that their light has been stretched and shifted to invisible infrared wavelengths. The most distant galaxies are receding so rapidly and their light is stretched so far in wavelength that they are invisible even to the Hubble telescope.

Webb’s infrared vision was designed to expose and explore these regions, which represent the universe only a billion years old, when the first galaxies began to bloom with stars. The cosmos is now 13.8 billion years old.

Astronomers measure cosmic distances with a parameter called redshift, which indicates how much light from a distant object has been stretched. Just a few months ago, a redshift of 8, which corresponds to when the universe was about 646 million years old, was considered a high redshift. Thanks to Emma Curtis-Lake of the University of Hertfordshire in England and her colleagues, the record redshift is now 13.2, which corresponds to when the universe was just 325 million years old.

Curtis-Lake and his team had pointed the Webb telescope at a part of the sky called GOODS South, looking for galaxies that Hubble had been unable to detect. There were four of them, wraiths in the haze of creation heat. Later measurements confirmed that they were very far apart in time.

Jane Rigby, the telescope’s operations project scientist, said the flawless launch of the Webb telescope has left it with enough running fuel to keep it running for 26 years or more.


BBC-NEWS-SRC: http://www.nytsyn.com/subscribed/stories/6514794, IMPORTING DATE: 2023-01-02 20:00:06

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