Night Skies of Botswana, by Stephen O'Meara

Night Skies of Botswana, by Stephen O'Meara. Penguin Random House South Africa. Imprint: Struik Nature. Cape Town, South Africa 2020. ISBN 9781775846932 / ISBN 978-1-77-584693-2

Night Skies of Botswana by Stephen O'Meara is a guide to visual astronomy for novice stargazers.

Introduction

Visual astronomy is the study of the night sky using the human eye, with or without optical aids like binoculars. Anyone, anywhere, can become a visual astronomer - all it takes is a sense of wonder and a desire to learn more about the skies above. Botswana is well known as a premier tourist destination. The Okavango Delta - a fragile wetland system and UNESCO World Heritage Site - harbours some of the world's most endangered species of large mammals. What is less known is that much of the Botswana wilderness is the perfect natural environment for enjoying another wonder: the star-filled night sky, complete with the Southern Cross (one of the most sought-after constellations in the skies), the Eta Carinae Nebula (a monstrous cloud of gas and dust harbouring a supergiant star some four million times more luminous than the Sun), the Large and Small Magellanic Clouds (two dwarf galaxies being torn apart by our Milky Way) and so much more. People who see these wonders under natural, dark sky conditions are fortunate, because the natural sky is globally threatened by light pollution, making the stars - or the way we see them from Earth - an endangered phenomenon. Bright artificial light at.night infiltrates the sky, washing starlight away from view. It is estimated that 80% of the world's population lives under skyglow - the unnatural brightening of the night sky due to poorly shielded lighting. The brighter the sky appears at night, the fewer stars can be seen. Fortunately, much of Botswana is free from light pollution - especially in and around the Central Kalahari Desert, Okavango Delta and other pockets of low-density population - and the stars may be seen here in their diamond-like purity, much as they appeared to the indigenous people of Botswana in times gone by. The indigenous people of Botswana saw the stars long before astronomers did; their interpretations of the skies appear throughout the book in the form of star lore.

Light pollution: a threat to wildlife

Not only does artificial light mask the bounty of stars from our sight, it can confuse plants and animals that rely on the natural cycle of night and day. Poor artificial lighting can have deadly effects on many creatures, especially prey that rely on the cover of darkness to avoid detection. Wetland habitats, which are home to frogs (whose night-time croaking is part of their breeding ritual), are adversely affected by light pollution. Lighting directed upward into the sky can cause birds that rely on the Moon and stars for navigation to wander off course. Gross overuse of lights has also caused a decline in insect populations, negatively impacting all predatory species that rely on insects for food or pollination. [...]

Stephen O'Meara is well known in the astronomy community for his remarkable skills as a visual observer. He was the first to sight Halley's Comet on its 1985 return and also the first to determine the rotation period of the distant planet, Uranus. He has been recognised by the International Astronomical Union, which named Asteroid 3637 O'Meara in his honour. The author of several books, a regular contributor to astronomy journals, and a National Geographic-funded explorer, he also works as a photographer and videographer for National Geographic. He lives in Botswana with his wife, Deborah, where they run yoga and stargazing safaris.

This is an excerpt from Night Skies of Botswana, by Stephen O'Meara

Title: Night Skies of Botswana
Author: Stephen O'Meara
Publisher: Penguin Random House South Africa
Imprint: Struik Nature
Cape Town, South Africa 2020
ISBN 9781775846932 / ISBN 978-1-77-584693-2
Softcover, 15 x 21 cm, 184 pages, throughout colour images, maps