EXPLOREMY LIBRARY
Science
BBC Sky at Night

BBC Sky at Night July 2020

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.

Country:
United Kingdom
Language:
English
Publisher:
Immediate Media Company London Limited
Frequency:
Monthly
Read More
SPECIAL: Get 40% OFF with code: DIGITAL40
SUBSCRIBE
$60.24
12 Issues

in this issue

1 min.
welcome

Later this month stargazers are in for a treat, when two giants of the night sky, Saturn and Jupiter, both reach opposition within a week of each other. Around this time they’ll be close together, and at their highest and brightest in the sky. We’ve got all the essential details you need to make the most of this wonderful summer evening view in the Sky Guide from page 39; it’s a foretaste of December’s Great Conjunction, when these two gas giant planets will appear as one bright star to the naked eye. Train a telescope on these worlds and you’ll reveal even more wonders: Saturn its majestic rings, and Jupiter its retinue of moons. Jenny Winder’s article on page 64 will really enrich your observations of the former, while Will Gater’s…

1 min.
this month’s contributors

Will Gater Astronomy journalist “This was a fascinating story to write. Io’s dynamism is just amazing and the possibility we might see a mission to study it in the coming years is really exciting. Will takes an in depth look at Io, Jupiter’s moon. page 26 Pete Lawrence Sky at Night presenter “Mars fever is starting to take hold as the planet improves in both position and appearance ahead of a very favourable opposition in October”. Pete provides top tips for observing the Red Planet. page 32 Mary McIntyre Outreach astronomer “This was a really fun project. It’s amazing what you can make with very basic ingredients and I learned so much about Eros.” Mary enjoys making a realistic model of a near-Earth asteroid. page 66…

2 min.
jupiter alight

GEMINI NORTH TELESCOPE, 7 MAY 2020 When it reaches opposition in the middle of this month, we can expect to get our best views of Jupiter for the year – but nothing like this. One of the highest resolution pictures of the planet ever taken from Earth, it was captured by the Gemini North 8.1m diameter infrared telescope at Hawaii’s Mauna Kea. Researchers used ‘lucky imaging’, assembling the picture from hundreds of very short-exposure shots, with only the sharpest portions – where the blur of Earth’s atmosphere was minimal – selected to build a global mosaic. Infrared light can pass through Jupiter’s clouds to reveal the deeper layers of its atmosphere. Alongside Hubble’s optical observations and radio data from the Juno spacecraft, the observatory is helping to reveal the secrets of our Solar…

1 min.
nearest stellar-mass black hole revealed

Astronomers have discovered a black hole just 1,000 lightyears from Earth, making it the closest black hole known to date. It’s the first stellar-mass black hole observed which isn’t interacting with its environment, making it truly black. All other black holes we know of in our Galaxy cause great disturbances in the surrounding gas, which then emit bright radiation, revealing the otherwise invisible objects to astronomers. However, this black hole has no such bright emission, and was only discovered as gravitationally bound to two stars in the system HR6819, one of which looks as if it’s being pulled on by an unseen companion. “An invisible object with a mass at least four times that of the Sun can only be a black hole,” says Thomas Rivinius from the European Southern Observatory (ESO),…

1 min.
comment

When I spoke to Thomas Rivinius I was fascinated by the accidental nature of the discovery. The team didn’t set out to find a black hole, but were interested in the properties of this unusual system. One of the two ‘normal’ stars spins quickly, the other slowly, an odd combination for a stellar system where they must have evolved together. Although ESO’s discovery had made headlines, Thomas explained with regret that they still hadn’t answered their original question. The black hole adds a further mystery – such objects are supposed to form in supernovae; how can a system bound by gravity survive such an event without being ripped apart? HR6819 will keep us guessing. Chris Lintott co-presents The Sky at Night…

1 min.
dinosaurs doomed by steep asteroid

The asteroid which killed the dinosaurs struck Earth at the deadliest angle possible, according to a recent set of simulations. Around 66 million years ago, a giant meteor impacted Earth releasing vast amounts of carbon dioxide, water and sulphur into the atmosphere, creating a nuclear winter and killing off 75 per cent of all life on Earth, including the dinosaurs. By combining geological data from the resulting Chicxulub crater and simulations of the strike, planetary scientists have determined the asteroid came in towards Earth at a steep angle, around 60˚. “We know that this was among the worst case scenarios for the lethality on impact, because it put more hazardous debris into the upper atmosphere and scattered it everywhere – the very thing that led to a nuclear winter,” says Gareth Collins,…