BBC Sky at Night

BBC Sky at Night April 2018

Sky at Night magazine is your practical guide to astronomy. Each issue features the world’s biggest and best night sky guide complete with star charts, observing tutorials and in-depth equipment reviews to ensure that amateur astronomers never miss those must-see events.

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United Kingdom
Immediate Media Company London Limited
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12 Udgivelser

i denne udgave

5 min

The Sun in h-alpha is a glorious thing. Although suitable filters are quite expensive, their price has come down considerably and many now have access to this equipment either through direct ownership or via clubs and societies. The expense comes down to the fine tolerances to which these filters have to be made. Essentially, they need to permit a very narrow set of wavelengths centred on 656.28nm to pass through. When this is achieved, the view is exhilarating. All wavelengths of light are blocked except that associated with the principle emission line of excited hydrogen atoms in the visible part of the spectrum. Suddenly, the relative quiet of the white light Sun is transformed into a seething mass of hydrogen plasma contorted by complex magnetic fields. The Sun’s photosphere appears covered by…

2 min

Ask a planetary biologist to list where in the Solar System is most likely to harbour life and occupying several of the top spots will be the icy moons. These frozen satellites of the gas and ice giants may appear to be the last place for life to gain a foothold, but all is not as it seems. On page 36, Elizabeth Pearson peers beneath their surfaces to uncover oceans of liquid water and speaks to the scientists planning missions to these strange cryovolcanic worlds. It’s only with space missions that we have gained such an understanding of the conditions on bodies hundreds of millions of kilometres from Earth. To understand the quality of observations astronomers achieved in the past, astro-adventurers Scott Lange and Nick Foster set off to the 19th-century…

1 min
skyatnight lots of ways to enjoy the night sky...

TELEVISION Find out what The Sky at Night team will be exploring in this month’s episode on page 19 ONLINE Visit our website for reviews, competitions, astrophotos, observing guides and our forum FACEBOOK All the details of our latest issue, plus news from the magazine and updates to our website PODCAST The BBC Sky at Night Magazine team discuss the latest astro news in our podcast iPHONE/iPAD Get each month’s issue on your iPad or iPhone, now with bonus image galleries TWITTER Follow @skyatnightmag to keep up with the latest space stories and tell us what you think…

1 min
amateur finds supernova

An amateur astronomer from Argentina who made history in 2016 when he captured the moment a supernova exploded has had his observations published. Víctor Buso made his serendipitous discovery while taking images of the spiral galaxy NGC-613 to test a new camera for his 16-inch telescope. “Professional astronomers have long been searching for such an event,” says Alex Filippenko from the University of California, Berkeley, who followed up the discovery with the Lick and Keck observatories. The observations, published in Nature in February, reveal that the blast was a Type IIb supernova, created by the explosion of a star that had lost its outer hydrogen. “Observations of stars in the first moments they begin exploding provide information that cannot be directly obtained in any other way,” says Filippenko. “This is an outstanding…

1 min
beneath the surface

The idea of a planet with cryovolcanic activity had never been considered before the Voyager missions, as it was thought the icy moons would be frozen solid. They are so far from the Sun that their surface temperatures are several hundred degrees below 0ºC and all the residual heat – the thing that keeps our own planet’s mantle from solidifying – should have dissipated. Without a mantle, there can be no volcanism. What planetary scientists didn’t account for, however, was the tidal tug-of-war between the various moons and their planet. This gravitational pull flexes the moons, keeping layers moving and preventing them from freezing completely. Instead of being frozen, then, these moons have liquid water oceans dozens of kilometres deep, sandwiched between the icy crust and a rocky core. In most cases,…

2 min

Email us at inbox@skyatnightmagazine.com Folding space Thought I’d share my idea for making good use of my out-of-date monthly stargazing guides: I’ve turned them into a modular origami constellation star. Alice Hanney, via email Ingenious, Alice! Origami’s very useful for spacecraft engineers, helping them find efficient ways of folding solar panels. – Ed Intensifying Newton I was interested to read your article on the 50th anniversary of the Isaac Newton Telescope (‘A second chance at first light’, December 2017 issue). In the late 1960s I worked at Marconi Instruments, helping with the experiments that paired a Marconi Image Intensifier with the Isaac Newton Telescope to increase its sensitivity. One night in June 1969, we set up the intensifier with the telescope, enabling the astronomers to enhance the image on the telescope by reducing the noise. I…