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A section of pink plasma superimposed on JET vessel equipped with the ITER-Like wall

The Joint European Torus has started conducting experiments with tritium fuel.Credit: EUROfusion (CC BY 4.0)

Fusion reactor set for fuel test run

A mini version of ITER — the world’s biggest nuclear-fusion experiment — is gearing up to start pivotal fuel tests. The Joint European Torus (JET) in Britain is a sibling of the ITER project in France: it has the same doughnut-shaped ‘tokomak’ design as the French project, but one-tenth of its volume. In June, JET will try to fuse tritium and deuterium, the fuel mix that ITER will use. ITER aims to someday create more power from a fusion reaction than is put in — which has never before been demonstrated.

Nature | 5 min read

No sign of Planet Nine

The hypothesis that there is a giant planet at the fringes of the Solar System has been dealt a blow by an analysis of distant, icy objects. The findings cast doubt on the evidence that the six trans-Neptunian objects (including Pluto) are under the gravitational pull of a huge planet. The research doesn’t rule out the possibility of a ninth planet orbiting the Sun, and astronomers need more data to put the debate to rest. “I can’t say that Planet Nine is dead, but I can say there’s no evidence for it,” says astronomer Samantha Lawler.

Nature | 5 min read

Reference: arXiv preprint

Infographic of the week

Gamma-ray factory. Explainer diagram showing how gamma rays are produced.

COVID-19 coronavirus update

Can COVID vaccines stop transmission?

As countries roll out vaccines that prevent COVID-19, studies are underway to determine whether shots can stop people from getting infected and passing on SARS-CoV-2. Vaccines that prevent transmission could help to bring the pandemic under control if they are given to enough people. Preliminary analyses suggest that at least some vaccines are likely to have a transmission-blocking effect. But confirming that effect — and how strong it will be — is tricky because a drop in infections in a given region might be explained by other factors, such as lockdowns and behaviour changes. “These are among the hardest types of studies to do,” says infectious-disease epidemiologist Marc Lipsitch.

Nature | 5 min read

500,000 deaths in the United States

With personal stories and a sobering graphic on its front page, The New York Times attempts to grapple with the US COVID death toll. Half a million people in the country have died — that’s more than it lost on the battlefields of the First World War, the Second World War and the Vietnam War combined. “This will be a sad day in our history,” says epidemiologist Ali Mokdad of the grim milestone. “Our grandchildren and future generations will look back at us and blame us for the biggest failure in facing a pandemic, in the country that’s the richest country in the world.”

The New York Times | 10 min read

6 years

The gap between the life expectancies of Black and white people in the United States, the widest it has been since 1998. Overall life expectancy in the country fell by a full year in the first six months of 2020, driven largely by COVID-19. (The New York Times | 6 min read)

Coronapod: our future with SARS-CoV-2

In January, Nature asked more than 100 immunologists, infectious-disease researchers and virologists working on SARS-CoV-2 whether it could be eradicated. Almost 90% of respondents think that the coronavirus will become endemic — meaning that it will continue to circulate in pockets of the global population for years to come. But failure to eradicate the virus does not mean that death, illness and social isolation will continue on the scales seen so far. The future will depend heavily on the type of immunity people acquire and how the virus evolves.

Nature Coronapod Podcast | 16 min listen

Read more: The coronavirus is here to stay — here’s what that means (Nature | 11 min read)

Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts or Spotify.

Features & opinion

Gorge Carruthers with a gold-plated ultra-violet camera/spectrograph

Credit: NASA/Zuma Wire

George Carruthers, pioneering astronomer

Space scientist George Carruthers, who designed the first telescope that went to the Moon, died in December, aged 81. Carruthers designed an ultraviolet camera for the Apollo 16 mission, which landed on the Moon in 1972 — the first space-based observatory to survey Earth’s upper atmosphere and peer into deep space. Carruthers, one of the first Black space scientists at NASA, was a dedicated teacher and mentor for Black scientists and engineers, as well as for those from under-represented communities in research and groups campaigning for equity in academia and industry. “Usually reserved, his demeanour was transformed when he was generously sharing his wisdom and his scientific and engineering prowess,” write former colleague Robert Meier and historians Angelina Callahan and David DeVorkin.

Nature | 5 min read

What Texas teaches about our climate future

Winter storms that led to the widespread loss of power and water services in Texas have revealed the United States’ vulnerability to extreme weather. Everything from sewers to roads must be radically revitalized to keep pace with the changing climate, argue experts in energy, infrastructure and emergency management. “We are colliding with a future of extremes,” said Alice Hill, who oversaw planning for climate risks on the National Security Council during the administration of former president Barack Obama. “We base all our choices about risk management on what’s occurred in the past, and that is no longer a safe guide.”

The New York Times | 11 min read

Where I work

Geraldine Cox poses for a portrait in her artists studio with her feet up on the desk, surrounded by brushes and canvases

Geraldine Cox is an artist in London.Credit: Leonora Saunders for Nature

Geraldine Cox mixes the palettes of art and physics by illustrating phenomena such as light-interference patterns. (Nature | 3 min read)

Quote of the day

“We argue that it is possible to be both critical and professional, and that no author deserves to be the recipient of demeaning ad hominem attacks regardless of supposed provocation.”

The authors of a paper that addressed unprofessionalism in the peer-review process evaluate some of the critical responses to their findings. (BMC paper)