Humans would have first seen Kata Tjuta very shortly after arriving in Australia 50,000 years ago. Alan Cooper

When did Aboriginal people first arrive in Australia?

Aboriginal Australians have effectively been on their country for as long as modern human populations have been outside of Africa. We have a limit as to how long ago that was: around 50,000 years.
US F/A-18 footage of a UFO (circled in red). Creative Commons Attribution-Share Alike 4.0 International license. Parzival191919

Are we alone? The question is worthy of serious scientific study

About 5 percent of all UFO sightings cannot be easily explained by weather or human technology. A physicist argues that there's compelling evidence to justify serious scientific study and that the skeptics should step aside – for the sake of humanity.
Normal IT security practices might not protect you from malicious attacks that enter your system through everyday devices, such as USB keys. Shutterstock

How suppliers of everyday devices make you vulnerable to cyber attack – and what to do about it

Malicious code or deliberate design faults can be inserted into everyday business products before they even leave the original manufacturer. Here's how you can protect yourself.
Galaxy cluster MACS J1149.5+2223 taken with the Hubble Space Telescope. The inset image is the very distant galaxy MACS1149-JD1. ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, W. Zheng (JHU), M. Postman (STScI), the CLASH Team, Hashimoto et al.

When did the lights first come on in the universe? A galaxy close to the dawn of time gives a clue

Astronomers have indirectly spotted some of the first stars in the universe by making their most distant detection of oxygen in a galaxy that existed just 500m years after the Big Bang.

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