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S2022 E6 The James Webb Road Trip
本集简介

On 12 July 2022 the Sky at Night joined the rest of the world to watch as the James Webb Space Telescope released its long-awaited first images. And it didn't disappoint. Stars and galaxies were revealed in such detail that they blew even the most experienced astronomers away. However, as spectacular as these images were, it was the data that they represented that really excited the scientists watching.

Chris Lintott travels around the country, meeting some of the scientists getting their hands on the very first batches of data coming from the JWST. His first stop is Professor Andy Bunker at the University of Oxford, who is pushing the world's newest space telescope to its limits to look for some of the first stars and galaxies formed after the big bang.

Chris also meets Dr Mika Matsuura of Cardiff University. She is studying the gas structures that dying stars exude as they reach the end of their lives. Mika explains how the incredible infrared capabilities of the JWST allow her to probe the discs of dust and gas around nebula and reveal the surprising conditions that form them.

Chris then heads on to the University of Bristol to visit Dr Hannah Wakeford, who is incredibly excited by her data, data that is revealing the secrets of the atmospheres of exoplanets orbiting far-flung stars. Hannah's method of studying exoplanets uses the JWST to measure the light from a target star as an exoplanet ‘transits' in front of it, briefly and almost imperceptibly dimming it. It is these incredibly precise measurements, only made possible by the sensitivity of this new supertelescope, that she hopes will change what we know about the atmospheric composition of these distant worlds.

Finally, Chris visits Professor Leigh Fletcher at the University of Leicester. Leigh is using the space telescope to look a little closer to home and shows Chris the latest images of Jupiter revealed in a whole new light by the JWST's infrared data. He explains to Chris the difficulties of capturing large bright objects in the telescope's small field of view, and what his plans are for studying our solar system's gas giants.

Meanwhile, Maggie Aderin-Pocock gives a JWST masterclass in the studio. Why is this telescope so revolutionary and how exactly does it work? She looks at why the JWST is observing light from the infrared part of the electromagnetic spectrum, and also why scientists chose to place the telescope in a location so far from Earth that we could not fix it if something went wrong. Maggie also explores the instruments that call the telescope home and takes a closer look at some of the tricks they have up their sleeves.

上一集
2022/07/11 S2022 E5
The Sky at Day

The British weather is often the enemy of stargazers up and down the country. A forecast of a couple of hours of cloud cover will disappoint even the most determined of amateur astronomers. So, this month, the Sky at Night becomes the ‘Sky at Day' to provide an alternative range of spectacles to observe and activities to partake in, ideal when the nights are short, and the stars are hiding behind the clouds.

The most obvious spectacle to observe is of course our own star, the sun. A moment is needed to appreciate that whilst amateurs and scientists alike spend lifetimes and whole careers searching after distant stars in the night sky, we have a star on our celestial doorstep that we can actually send a space probe to. In 2018, that is exactly what Nasa did. The idea for the Parker Solar Probe was conceived in 1958, but it took 60 years to develop the technology to make it possible, namely, working out how to prevent it from melting.

Justin Kasper, principal investigator for the Sweap instrument (Solar Wind Electrons Alphas and Protons investigation), spoke to Chris about how the probe entered the sun's atmosphere and made incredible discoveries about its structure. It revealed that the boundary where solar material anchored to the sun first escapes and becomes the solar wind is not a smooth ball but has spikes and valleys that wrinkle the ‘Alfvén critical surface'. Previously, the coronal streamers that cause this wrinkling had been observed from a distance but never measured directly until Sweap came along. Its discoveries are altering what scientists know about the way in which the sun's atmosphere transforms into the solar wind.

Back on earth, Dr Hannah Wakeford shows us how observing the sun as it rises and sets in the sky can tell us a huge amount about the composition of our atmosphere and the weather on the horizon. The adage ‘Red sky at night, shepherd's delight. Red sky in the morning, shepherd's warning' is dismissed as many as an old wives' tale. However, due to our unique position in the mid-latitudes, it turns out that this saying may be more accurate than many think. Hannah also explores, as light travels from the sun to our eye, how different wavelengths are absorbed and scattered by the atmosphere, and the light that completes the journey to our eye or our telescope can reveal the combination of gases that make up the atmosphere. Hannah explains how this process has helped scientists to work out the composition of the atmosphere of other planets in our solar system and even exoplanets orbiting distant stars.

Exploring during the day can sometimes unlock a whole new scientific field. Guest presenter George Dransfield spoke to urban micrometeorite hunter Jon Larsen about how he accidentally discovered a micrometeorite on his garden table whilst eating strawberries on a fine summer's day, and how, ever since, he has been pioneering a method for amateurs across the globe to discover pieces of stardust in their own back garden. George tries to find some micrometeorites of her own, and in the process, learns about the huge spectrum of micrometeorites that Jon, along with his partner Jan Braly Kihle, has found and photographed in astounding detail.

As well as hunting meteorites and watching the sunset, there is also stargazing to be done during the day. Amateur astronomer and outreach hero Simon Holbeche from Bath spends every sunny weekend showing members of the public the sun in a whole new light. Using different specialist telescopes and heavy solar filters, Simon is able to show passers-by the incredible sunspots on the solar surface and the exploding prominences in the sun's atmosphere. His enduring hope is that those passers-by might become hooked by what they've seen, and one day come back to see the sky at night.