BBC Sky at Night

BBC Sky at Night

August 2021

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
USD 6.89
USD 62.16
12 Números

en este número

2 min.

As well as looking up at what the night sky has in store, this issue we’re also reversing the view and looking back at planet Earth from space. In our feature on page 36, Rob Banino speaks to scientists operating satellite missions monitoring our planet’s vital statistics, to investigate how they will provide the data that will underpin global agreements addressing rising levels of carbon dioxide in Earth’s atmosphere. The view remains reversed for another feature too, where Toby Ord tells us about his project to digitally restore photographs of Earth taken by Apollo astronauts. On their way to and from the Moon, the Apollo crews were the first – and so far only – humans to see our planet from the vantagepoint of deep space, and it was a sight…

1 min.
this month’s contributors

Rob Banino Science Journalist “We have to cut our CO2 emissions to avoid climate change, but without knowing how much CO2 we’re responsible for, we can’t tell if our efforts work.” Rob discovers the satellites that monitor the gases in Earth’s atmosphere, page 36 Ezzy Pearson News editor “Considering Juno was supposed to be ending this month, looking into all the things it has planned during its extended mission was thrilling.” Ezzy looks forward to what’s next for Juno as its Jupiter mission is extended, page 60 Emily Winterburn Physicist & historian “I enjoyed writing about noctilucent clouds, and noticing how as astronomers’ interests have changed, so too has our understanding of this phenomenon.” Emily looks at the ongoing discovery of NLCs, page 72…

1 min.

Since its discovery, DF2 has caused controversy. Detecting the influence of dark matter on small systems is a difficult task, and showing it isn’t there is very hard. This also adds strength to claims about the dark matter-free status of another satellite of NGC 1052-DF4, which has similar properties to DF2. These results challenge our ‘standard’ conception of how galaxies form in a Universe dominated by dark matter, and alternative ideas that remove any need for mysterious particles by fiddling with the theory of gravity. With new clues needed by both sides of that great debate, I’d expect more observations of this intriguing system in the near future. Chris Lintott co-presents The Sky at Night ALYSSA PAGAN (STSCI), NASA/JAXA/ISAS/DARTS/DAMIA BOUIC/VR2PLANETS, NASA/SMITHSONIAN INSTITUTION/LOCKHEED CORPORATION, NASA/JPL-CALTECH…

1 min.
recording your observations

If you get into watching the Perseids this month, why not keep a methodical record of the meteors you see over each hour. This will make an interesting keep-sake of a successful night of observing and can aid scientists with their work too. Records of visual meteor observations are still used today by researchers as a way to gather information about the meteoroid streams left by comets and asteroids. Pictures, video and eyewitness reports can also be a key source of useful data, particularly when it comes to bright meteors known as fireballs, as these can sometimes drop meteorites to the ground. As these started life as fragments of other bodies in the Solar System, such as asteroids, this material can be of scientific importance and there are teams worldwide who try…

1 min.
the sky guide

AUGUST 2021 A MONTH OF METEORS Enjoy a promising Perseid peak on 12 August and an Aurigids outburst at the end of the month DOUBLE THE VIEW Observe Jupiter and Saturn, both at opposition in August FIND THE ‘ZENO STEPS’ Discover one of the Moon’s lesser-known clair-obscur effects 16-PAGE CENTRE PULLOUT About the writers Astronomy expert Pete Lawrence is a skilled astro imager and a presenter on The Sky at Night monthly on BBC Four Steve Tonkin is a binocular observer. Find his tour of the best sights for both eyes on page 54 Also on view this month... ♦ Jupiter’s double moon and shadow transits ♦ Delaunay, the Moon’s misshapen crater ♦ Meteor trains, and how to observe them Red light friendly To preserve your night vision, this Sky Guide can be read using a red light under dark skies Get the Sky Guide weekly For weekly…

1 min.
comets and asteroids

Minor planet 89 Julia reaches opposition in Aquarius this month, shining at mag. +9.0 near the Water Jar asterism. The Water Jar, or ‘Steering Wheel’, is formed of four similar brightness stars in the northern regions of Aquarius. It sits south of the triangle that forms the upside-down head of Pegasus and to the west of the faint Circlet asterism in Pisces. Its four stars are mag. +4.3 Zeta (ζ) Aquarii in the centre, mag. +4.4 to +4.7 variable star Pi (π) Aquarii to the north, mag. +4.0 Eta (η) Aquarii to the east and mag. +3.8 Gamma (γ) Aquarii to the west. The asterism lies 5° east of mag. +2.9 Sadalmelik (Alpha (α) Aquarii) and is quite easy to locate. At the start of August, 89 Julia is located a…