When the James Webb Space Telescope (JWST) launched on Christmas Day 2021, we knew its groundbreaking capabilities had the potential to rewrite the astronomy textbooks. And this incredible spacecraft has not disappointed.
The deployment of its giant segmented mirror and sun shield went without a hitch, its science instruments are operational and exceeding expectations, and the launch trajectory was so precise that there's fuel to maintain its orbit for many years to come.
Right from its first observations, the space telescope has given astronomers new puzzles to solve and new questions to pursue. In particular, it is challenging what we thought we knew about the early evolution of galaxies.
'Impossible' galaxies
JWST's intriguing deep-field observations of faint light from the early, distant Universe reveal stars and galaxies that seem to be much larger than expected.
The CEERS (Cosmic Evolution Early Release Science) survey, led by Prof Steven Finkelstein of the University of Texas at Austin, used JWST's NIRCam instrument to look back as far as the epoch of reionisation, just after the so-called dark ages of cosmic evolution, to study the structure of galaxies in the very early Universe.
It found more of them than predicted, and they appear bigger and brighter than expected. According to our best models of how the infant Universe developed, they aren't supposed to be there so early or look as they do.
Some of the first survey results have even indicated there are mature-looking disc galaxies reminiscent of our own Milky Way present as early as 10 billion years ago. We were expecting a more chaotic picture, with predominantly irregular galactic structures interacting violently. JWST's advanced resolution, coupled with its ability to observe very distant early objects in infrared, has made us think again about how soon galaxies began to form and mature.
この記事は BBC Sky at Night Magazine の August 2024 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は BBC Sky at Night Magazine の August 2024 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
Could We Find Aliens by Looking for Their Solar Panels?- Designed to reflect ultraviolet and infrared, the panels have a unique fingerprint
Researchers searching for life beyond Earth spend a lot of time thinking about what telltale signs might be detectable astronomically. Forms of unambiguous evidence for the presence of life on another world are known as biosignatures. By extension, techno signatures are indicators of activity by intelligent, civilisation-building life.
Antimatter- In our continuing series, Govert Schilling looks at antimatter, the strange counterpart to most of the matter filling our Universe
Particles and corresponding antiparticles are very much alike, except they have opposite electrical charges. For instance, the antiparticle of the electron - known as the positron - has the same tiny mass, but while electrons carry a negative electrical charge, positrons are positively charged.
Where Have All The Milky Way's Early Stars Gone?- Our Galaxy has a curious lack of pristine stars
The Big Bang produced a Universe filled almost exclusively with hydrogen and helium; all other elements - what astronomers call metals - were produced by stars, supernovae and everything that happens later. So if you can pick out a pristine star with no metals polluting it from among the billions in the Milky Way, then you are likely to have a star dating from our Galaxy's earliest days.
Inside The Sky At Night - Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST
Two years ago, exoplanet scientist Hannah Wakeford received some of the first data from the JWST. In July's Sky at Night, we discovered what she's learned since then.
How to stack DSLR data in Siril
Easily combine multiple frames to boost detailin your astro photos
Lunar occultation of Saturn
You'll need to strike a balance on 21 August to capture the Moon covering the ringed planet
How to plot a variable star light curve
A rewarding project to chart stars that change brightness
Smartphone photography with a telescope
Mary Mcintyre explains how to get impressive night-sky images using your phone
Once-a-century solar storm is overdue
If a Carrington Event struck today it would be catastrophic, says Minna Palmroth
The new era of human spaceflight
There's been a step-change in crewed space missions since the dawn of the 21st century. Ben Evans charts its course and looks ahead to future horizons
