Tom Metcalfe
Tom Metcalfe is a freelance journalist and regular Live Science contributor who is based in London in the United Kingdom. Tom writes mainly about science, space, archaeology, the Earth and the oceans. He has also written for the BBC, NBC News, National Geographic, Scientific American, Air & Space, and many others.
Latest articles by Tom Metcalfe
![A photo of tall, upright stones scattered in the desert](https://cdn.mos.cms.futurecdn.net/DGeLjNwc2gAn2pYf6CrbVg-320-80.jpg)
Nabta Playa: A mysterious stone circle that may be the world's oldest astronomical observatory
By Tom Metcalfe published
Nabta Playa in Egypt is an ancient stone circle that researchers suspect was used to determine the summer solstice, which signaled rain was on the way.
![people in a sandy marsh, near a circle of stones sticking out of the surface.](https://cdn.mos.cms.futurecdn.net/Bver66sFNbFfp6AWcctcZM-320-80.jpg)
4,000-year-old 'Seahenge' in UK was built to 'extend summer,' archaeologist suggests
By Tom Metcalfe published
The construction of the monument and another beside it more than 4,000 years ago corresponds to a time of bitter cold.
![Wooden slips marked with Chinese characters that relate to the traditional Tiangan Dizhi astronomical calendar.](https://cdn.mos.cms.futurecdn.net/tQSSujVo8mwX8FqBPhWERC-320-80.jpg)
2,000-year-old 'celestial calendar' discovered in ancient Chinese tomb
By Tom Metcalfe published
Archaeologists in China have unearthed a mysterious set of rectangular wooden pieces linked to an ancient astronomical calendar.
![Scientists have discovered a previously unknown breeding colony of emperor penguins in satellite photographs of West Antarctica.](https://cdn.mos.cms.futurecdn.net/LSzrdTGyqnGXh2QJRrTsqg-320-80.jpg)
Hidden, never-before-seen penguin colony spotted from space
By Tom Metcalfe published
Satellite photos showing poop stains in the West Antarctic snow and ice have revealed a previously unknown breeding colony of emperor penguins.
![The Hyades star cluster (pink) curls across the sky amid well-known constellations (green). The cluster is at the center of a controversial new study proposing an alternative to Newton's theory of gravity.](https://cdn.mos.cms.futurecdn.net/ThzP8FfRvVq9a9ATi5UVem-320-80.jpg)
Lopsided star cluster may disprove Newton and Einstein, controversial new study claims
By Tom Metcalfe published
An uneven distribution of stars in several nearby clusters may offer evidence of MOND — a controversial theory of gravity that disputes Newton and rejects the existence of dark matter.
![A previously unpublished note by Galileo refers to criticism by the Italian scholar Ludovico delle Colombe, who had suggested that the "new star" seen in 1604 was always there, but had only recently been seen.](https://cdn.mos.cms.futurecdn.net/Npw9ZLy5ighSoqtnPJPQCi-320-80.jpeg)
Forged Galileo manuscript leads experts to controversial book he secretly wrote
By Tom Metcalfe published
A manuscript attributed to Galileo Galilei found to be a forgery in August has led to the discovery that a different, controversial book was authored by the celebrated Italian astronomer.
![A fragment of transparent quartz crystal found at Neolithic burial site.](https://cdn.mos.cms.futurecdn.net/87ZtDnGiayWNfwGHzUKodB-320-80.jpg)
'Magical' rock crystals found at Stone Age ceremonial site in England
By Tom Metcalfe published
Neolithic people sprinkled the crystals over burials.
![Researchers discovered a highly reactive chemical that they had long thought was too unstable to last under atmospheric conditions.](https://cdn.mos.cms.futurecdn.net/AT25Wz5VpEdaQfrAJ7k2YE-320-80.jpeg)
New, extremely reactive chemical discovered in the atmosphere
By Tom Metcalfe published
Millions of tons of a type of extremely reactive chemical can form in the atmosphere each year, with implications for health and the global climate.
![The doughnut-shaped fusion chamber of the TCV contains the superheated hydrogen plasmas in powerful magnetic fields to keep it from damaging the walls.](https://cdn.mos.cms.futurecdn.net/pH85rvgwvS9NViJrxafLmA-320-80.jpg)
Physicists just rewrote a foundational rule for nuclear fusion reactors that could unleash twice the power
By Tom Metcalfe published
Future fusion reactions inside tokamaks could shine even brighter than before, thanks to groundbreaking new research to find the maximum density of the hydrogen plasma fuel that powers them.
![The instruments on NASA's Solar Dynamics Observatory can reveal the intense magnetic fields generated by the sun that tangle as it rotates.](https://cdn.mos.cms.futurecdn.net/2yFdpFmPnWFzwFMZy2D2eS-320-80.jpg)
First new sunspots in 40 days herald coming solar cycle
By Tom Metcalfe last updated
Two new sunspots have ended a long period of relative quiet on the surface of our blazing host star, heralding the start of a new 11-year cycle of sunspot activity.
![The two massive sunspot groups, known as AR 2993 and AR 2994, became visible a few days ago at the northeast limb of the sun after becoming active while still hidden by the sun's disk.](https://cdn.mos.cms.futurecdn.net/hLLwxk5WZT4g7Efqr4tMCW-320-80.jpeg)
New swarms of sunspots are so gigantic they could devour Earth whole
By Tom Metcalfe last updated
Two immense swarms of sunspots have popped into view on the surface of the sun, hinting at the increased possibilities of vivid auroras and potentially damaging solar flares over the months to come.
![The Mars Curiosity rover's Mast camera snapped this intriguing image of the Red Planet, showing a "doorway" structure, on May 7, 2022, or Sol 3466 in Martian days.](https://cdn.mos.cms.futurecdn.net/dfnwS4rM4ohKGSTytvmHHC-320-80.jpeg)
The 'doorway' seen on Mars is not for aliens. Here's how it really formed.
By Tom Metcalfe published
The internet erupted after a photograph from the Mars Curiosity rover appeared to show an "alien door," experts are pretty sure it's just a natural feature.
![Mikoyan MiG-31K fighter jets with Kinzhal hypersonic missiles fly over Moscow's Red Square during the Victory Day military parade in Moscow, Russia, on May 09, 2018. Russia has claimed it used these missiles for the first time in combat with Ukraine.](https://cdn.mos.cms.futurecdn.net/fGoPCnrDmCokmtdE2jz5eY-320-80.jpg)
Russia strikes Ukraine with new hypersonic missiles: Here's how they work.
By Tom Metcalfe published
Russia claims to have used its Kinzhal hypersonic missiles for the first time, in its invasion of Ukraine. Here's why these super-fast weapons are so concerning.
![The experimental TCV tokamak at Lausanne in Switzerland is used to test the behavior of hydrogen plasmas that will serve as fuel in future fusion reactors.](https://cdn.mos.cms.futurecdn.net/3qJ2j9oyG9TAKvhpJsZ94n-320-80.jpeg)
Nuclear fusion is one step closer with new AI breakthrough
By Tom Metcalfe published
The green energy revolution is getting closer.
![The fusion reactions at the National Ignition Facility takes place at the heart of the world's most powerful laser system, which consumes about 400 MJ of energy each time it's fired.](https://cdn.mos.cms.futurecdn.net/kepdtFTx6TQSVvFYr6WYU9-320-80.jpeg)
'Burning' hydrogen plasma in the world's largest laser sets fusion records
By Tom Metcalfe published
The secret behind a record-breaking nuclear fusion experiment that spit out 10 quadrillion watts of power in a split second has been revealed.
![Star trails are seen over the Nicholas U. Mayall 4-meter Telescope on Kitt Peak National Observatory near Tucson, Arizona.](https://cdn.mos.cms.futurecdn.net/FjoDRuV3a4kksa9f69rxXe-320-80.png)
Largest dark energy map could reveal the fate of the universe
By Tom Metcalfe published
A telescope in Arizona modified to measure the true distance of galaxies has produced the largest three-dimensional map of the universe ever.
![An aerial view of the crater from the explosion of the V2 rocket in 1944 being excavated last month. The site was an orchard when the rocket hit it 77 years ago.](https://cdn.mos.cms.futurecdn.net/46NNWLhSCVA529tzJCnvPj-320-80.jpg)
Remains of Nazi V2, the first supersonic rocket, unearthed in South East England
By Tom Metcalfe published
The remains of a V2 rocket fired by Nazi Germany at London during World War II have been unearthed in a field in the southeast of England, where it crashed and exploded before reaching its target.
![This aerial picture taken on July 27, 2021, shows a burned forest at Gorny Ulus, west of Yakutsk, in Siberia.](https://cdn.mos.cms.futurecdn.net/sahwkQH7JuQerB7ymzFGHD-320-80.jpeg)
Siberian wildfires dwarf all others on Earth combined
By Tom Metcalfe published
Smoke from massive wildfires in Russia's eastern Siberia region has reached the geographic North Pole "for the first time in recorded history," according to NASA.
![Snowcapped mountains in Akureyri, Iceland.](https://cdn.mos.cms.futurecdn.net/sMKRebbfF8hit2JWSjopmK-320-80.jpeg)
Iceland may be the tip of a sunken continent
By Tom Metcalfe published
Iceland may be the last exposed remnant of a nearly Texas-size continent — called Icelandia — that sank beneath the North Atlantic Ocean about 10 million years ago
![a black hole](https://cdn.mos.cms.futurecdn.net/Xw35NFRFRGmPgfFNNsnffk-320-80.jpg)
Dark matter could be made of black holes from the beginning of time
By Tom Metcalfe published
Evidence of collisions between black holes and neutron stars suggests dark matter might consist of concentrations of primordial black holes.
![The spiral galaxy NGC 5585, which is nestled on the tail of the Great Bear in the constellation of Ursa Major, is one of many that have revealed the presence of an invisible substance called dark matter.](https://cdn.mos.cms.futurecdn.net/nqtSf8VCa5pxQ3cbbG6vmC-320-80.jpg)
Scientists narrow down the 'weight' of dark matter trillions of trillions of times
By Tom Metcalfe published
Scientists are finally figuring out how much dark matter — the almost imperceptible material said to tug on everything, yet emit no light — really weighs.
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