Does launching rockets harm the environment?

In theory, yes. There are various ways a rocket launch can cause environmental damage, but in practice they make a very minor contribution to such damage compared to things we do in our everyday lives.

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Any rocket engine is powered by a chemical reaction of some sort, which may produce some polluting gases - although the most efficient reaction of all, the combustion of liquid hydrogen and liquid oxygen to make steam, is also the 'cleanest' in environmental terms. Gases left behind as the rocket blasts through the atmosphere make no substantial contribution to the greenhouse effect compared to cars and ground-based industry. Although these exhaust gases can damage the protective ozone layer about 12.4 miles up, recent research suggests they are only responsible for about one per cent of human-inflicted damage at most. All in all, the harm caused is insignificant compared to how much satellites and space experiments have taught us about the environment and how we can better take care of it.

WHAT MAKES AUSTRALIA’S BLUE MOUNTAINS BLUE?

The blue haze blanketing the Blue Mountains in New South Wales is commonly attributed to the area’s eucalyptus forests. A popular theory is that airborne droplets of eucalyptus oil combine with dust particles and water vapour, refracting rays of mainly blue light.

Another theory is they appear blue for the same reason the sky appears blue. Dust, water droplets and air particles scatter short wavelengths of blue light more than long wavelengths of red light. The air acts like a translucent plastic sheet, giving the mountains a blue tint. This explains why mountains without eucalyptus sometimes appear blue.

COULD WE SURVIVE BY JUST EATING INSECTS?