How close can a potentially dangerous asteroid get before it’s detected? Shutterstock/Alexyz3d

Why dangerous asteroids heading to Earth are so hard to detect

We're finding more near-Earth objects all the time, and the challenge is to identify those that could potentially hit us. So how come we missed one that caused a huge blast in December?
Fresh produce at a market in Blantyre, Malawi. Supplied

Connecting food waste and sanitation services can help African farmers

Across Africa less than 10% of the population is connected to a sewer system. But the waste could be used elsewhere.

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