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A view of the IS-901 satellite from MEV-1 during approach from approximately 20 metres, with Earth in the background.Northrop Grumman

For the first time ever, a space ‘tow truck’ has rescued a commercial satellite. US aerospace-technology company Northrup Grumman’s Mission Extension Vehicle-1, or MEV-1, docked with Intelsat 901, an ageing communications satellite, in late February. Last Friday, MEV-1 adjusted the satellite’s inclination and orbit to give it a new lease on life. MEV-1 itself has a lifespan of 15 years, and can dock to and undock from multiple satellites.

Ars Technica | 3 min read

A map of 850 distant galaxy clusters hints that the Universe might not be uniform. Combining data from US, European and Japanese X-ray space telescopes, researchers have revealed galaxy clusters that were around 30% brighter or fainter than expected, suggesting that their distances had been poorly estimated. Taking these clusters as beacons of the rate of cosmic expansion, the findings would mean that one region is expanding slower than the rest of the Universe, and another is expanding faster. Astrophysicist Megan Donahue comments that a lopsided expansion “would be astonishing and depressing” because it suggests that our understanding of the Universe could be permanently incomplete.

Scientific American | 6 min read

Reference: Astronomy & Astrophysics paper

Features & opinion

COVERING CLIMATE NOW This week, Nature joins more than 400 of the world’s media organizations in a week of intensive reporting called Covering Climate Now. For the second year running, we aim to focus attention on the need for urgent climate action. So in the Briefing this week, you’ll see more than the usual number of climate-change stories, although not exclusively. This year, the focus is on climate solutions. Listen to Nature’s chief magazine editor Helen Pearson tell the Nature Backchat podcast last year about why we are uniting with colleagues and competitors around the world to highlight the issue of climate change.

Cutting personal carbon emissions might slash 10 tonnes per person each year — and contributing to a successful campaign to shutter a coal-powered plant could eliminate one million times that, notes science writer Emma Marris. She argues that scientists are perfectly placed to help to hold governments and companies accountable on the climate — and that such activities need not conflict with our scientific objectivity and rigour. (Nature | 5 min read)

Nature | 5 min read

In 2019, the Urgenda Foundation, a Dutch non-profit group, successfully sued the government of the Netherlands for doing too little to reduce emissions. Dennis van Berkel, who was Urgenda’s legal counsel, argues that scientific evidence has a crucial role in arguing the case in climate lawsuits.

Nature | 5 min read