The accumulation of errors hampers the use of quantum computers. Although there are ways to design circuits so they detect and correct errors, this typically requires a substantial number of additional qubits. In this week’s issue, researchers at IBM present a protocol for low-overhead error correction in quantum computers. The researchers use low-density parity-check codes, which correct errors by monitoring several symmetries each supported on only a small set of qubits. This code performed as well as established error-correction protocols but crucially needed only about one-tenth of the qubits. This could make error-corrected quantum computers substantially smaller machines than previously assumed. The cover image offers an artistic rendering of the qubit connectivity required for the new protocol in which each qubit needs to interact with six others. Qubits are linked as if they were placed onto the surface of a torus.

The cover shows an artist’s impression of a planet being captured and ingested by one of the stars in co-moving pairs of stars. In this week’s issue, Fan Liu and colleagues present evidence suggesting about 1 in 12 stars might have ingested a planet. The chemical composition of a star can change when it engulfs a planet, so the researchers looked at binary star systems in which the two stars were born at the same time. By comparing the spectral signatures of the stellar twins, they were able to identify instances in which one of the stars had ingested a planet. They identified 91 pairs of close ‘co-natal’ stars and found evidence of planetary ingestion in about 8% of them.

The cover shows two stacked clouds illuminated by the glow of an overnight firestorm at Adams Lake, British Columbia, in August 2023, during a record-breaking fire season in Canada. Wildfires that deviate from the conventional diurnal cycle of ‘active day, quiet night’ and instead burn continuously through the night are anticipated to become more frequent under continued climate change. In this week’s issue, Kaiwei Luo and colleagues reveal the extent of this shift in wildfire behaviour in North America. The researchers examined 23,557 fires that occurred across the continent between 2017 and 2020. They found 1,095 overnight burning events in 340 individual fires, and noted that one-fifth of large fires had at least one overnight event. The team found that these overnight burns were driven by the increased availability of extremely dry fuel associated with droughts. As a result, the researchers suggest that drought conditions can help predict the likelihood of overnight burning and therefore help with fire management in the face of changing climate.

The cover shows homes under threat from rising sea levels in Summer Haven, Florida. In this week’s issue, Leonard Ohenhen and colleagues suggest that a considerable amount of land in 32 US coastal cities could be at risk of flooding by 2050. Combining models of changes in land elevation with projected rises in sea levels, the researchers estimated the flooding risk in the cites, including Boston, New Orleans and San Francisco. They note that a combination of coastal subsidence and rising sea levels could put an additional 1,006–1,389 km2 of land at risk of flooding by 2050, which could affect up to 171,000 properties. As a result, they call for improvements to flood defences and subsidence control to bolster current coastal protection.