Blurs

Deep in a remote Norwegian valley, strange lights have been appearing for decades. They can glow for seconds or remain visible for much longer. Some have apparently hovered, others moved slowly through the valley, while a small number of observations have been associated with unusually rapid movement.  They have been photographed, filmed and, importantly, detected by scientific instruments. Yet after more than 40 years of investigation, there is still no generally accepted explanation for what produces them. This is the mystery of the Hessdalen Lights. A valley with an unusual history Hessdalen is a valley in central Norway, approximately 30 kilometres northwest of Røros. It is around 12 kilometres long and is surrounded by mountainous terrain. Reports of unusual lights in the area predate modern investigations, but something changed dramatically in 1981. Residents began reporting strange luminous objects with increasing frequency. During the peak period, reports could reach approx...

Lithium is one of the strangest metals on Earth. It is the lightest metal known, soft enough to be cut with a knife, and highly reactive.  On its own, it doesn't look particularly impressive. Yet this unassuming element has become one of the most important raw materials of the modern technological world. It is inside the batteries powering smartphones, laptops, electric vehicles, power tools and increasingly, large-scale energy-storage systems. Lithium is also used in glass, ceramics, lubricating greases, aluminium alloys, pharmaceuticals and several industrial processes. But there is an obvious question hiding behind all those batteries: Where does all the lithium actually come from? And perhaps more importantly: What does it cost the planet to get it? What exactly is lithium? Lithium is chemical element number 3 on the periodic table. Its symbol is Li. It was first identified in 1817 by Swedish chemist Johan August Arfwedson, although commercially useful quantities would not be p...

Some of the most interesting evidence for ancient life does not look like a fossil. It can look like a wrinkle. Researchers studying Jurassic rocks in Morocco have identified unusual sedimentary structures that may record microbial communities living on the seafloor roughly 180 million years ago. That would not, by itself, be particularly surprising. Microbial life was already widespread in Earth's oceans. The strange part is where these structures formed. The sediments appear to have accumulated in relatively deep water — around 200 metres below the ancient ocean surface. That raises an important question. If sunlight was severely restricted at that depth, what was providing the energy for these organisms? One possibility is that they were not using sunlight at all. They may have been running an ecosystem on chemistry. And if that interpretation is correct, the discovery provides another reminder that the ancient ocean was probably far more biologically diverse — and far stranger ...

The Moon seems permanent. It rises, it sets, it controls the tides. It has been there throughout human history. But the Moon we see today is not the Moon that Earth had in the distant past. Our satellite is slowly moving away from us. At the same time, Earth's rotation is gradually slowing. Go backwards far enough and the relationship between Earth and Moon becomes dramatically different. The Moon would have been closer, the tides would have been stronger, Earth would have spun faster. Days would have been shorter. And the night sky would have looked completely unfamiliar. But this raises a more intriguing question. Could the young Earth have had a Moon that was fundamentally different from the one we know today? Not necessarily a different moon in the sense of another permanent satellite. But a Moon occupying a very different orbit, appearing vastly larger in the sky and exerting a much stronger influence on our planet. And could that changing relationship have affected the develo...