This article lists a number of significant events in science that occurred in the first quarter of 2021.
Events January
1 January – Beginning of the implementation of Plan S, an initiative for open-access science publishing launched in 2018 that requires papers from 2021 onwards from over 10 European countries that resulted from research funded by public grants to be published under an open licence in compliant journals or platforms, available to all. 4 January Media reports that engineers worldwide discuss a negative leap second and other possible measures as Earth spun faster in 2020. Researchers describe how the damage to nerve cells caused by motor neurone disease could be repaired by improving the energy levels in mitochondria. Scientists describe a CRISPR-Cas9 genome editing approach which could be used to treat wet age-related macular degeneration caused by VEGFA and Herpes simplex type 1: injection of engineered lentiviruses into the affected anatomical regions for transient editing without inducing off-target edits. 5 January – Using theoretical calculations, researchers suggest that humans would be unable to control a superintelligent AI.
6 January Scientists report the successful use of gene editing in mice with progeria, a premature aging disease. Chinese researchers report that they have built the world's largest integrated quantum communication network, combining over 700 optical fibers with two QKD-ground-to-satellite links for a total distance between nodes of the network of networks of up to ~4,600 km. The first systematic review of the scientific evidence around global waste, its management and its impact on human health and life is published, providing assessments, suggestions for corrective action, engineering solutions and requests for further research. It finds that about half of all the municipal solid terrestrial waste – or close to one billion tons per year – is either not collected or mismanaged after collection, often being burned in open and uncontrolled fires. Authors conclude that "massive risk mitigation can be delivered" while noting that broad priority areas each lack a "high-quality research base", partly due to the absence of "substantial research funding", which scientists often require. 7 January A potential mRNA vaccine for multiple sclerosis is presented by a collaboration including BioNTech, with a study in mice showing great promise for improving symptoms and stopping disease progression.
Scientists conclude that environmental factors played a major role in the evolution of the slowly-evolving, currently low-diverse Crocodilia (and their ancestor-relatives), with warmer climate being associated with high evolutionary rates and large body sizes. 8 January News outlets report that scientists, with the Juno spacecraft orbiting Jupiter, detected an FM radio signal from the moon Ganymede which is reportedly caused by cyclotron maser instability and similar to both WiFi-signals and Jupiter's radio emissions. A study about the radio emissions was published in September 2020 but did not describe them to be of FM nature or similar to WiFi signals. Scientists report the discovery of the most distant, and therefore oldest, quasar, J0313–1806. It is located 13 bn light-years away, does not yet have an accepted non-identifier name and significantly challenges theoretical models of early SMBH growth, apparently existing just ~670 million years after the Big Bang despite its large size. Archaeologists report that the African cultural phase, called Middle Stone Age, thought to have lasted from ~300–30 ka, lasted to ~11 ka in some places, highlighting significant spatial and temporal cultural variability. WASP-62b is confirmed to be the first hot Jupiter exoplanet without clouds or haze in its observable atmosphere. 12 January Scientists report the use of CRISPR/Cas9 genome editing to produce a tenfold increase in super-bug targeting formicamycin antibiotics. COVID-19 pandemic: The National Institute of Infectious Diseases of Japan reports the detection of significant variant of SARS-CoV-2 Lineage P.1 via testing of travelers from Brazil, which was later reported to originate from widespread circulation in Brazil. Researchers report that large populations consistently converge on highly similar category systems, relevant to lexical aspects of large communication networks and cultures.
13 January A new record high temperature of the world's oceans is reported, measured from the surface level down to a depth of 2,000 metres. In Lyon, France, the first transplant of both arms and shoulders is performed on an Icelandic patient. Astrophysicists report that energy extraction – with high efficiency – from rotating black holes with a high spin via reconnection of magnetic field lines of an externally supplied magnetic field that accelerates escaping plasma particles is possible. Advanced civilizations may be capable of doing so. Scientists report that all glacial periods of ice ages over the last 1.5 M years were associated with northward shifts of melting Antarctic icebergs which changed ocean circulation patterns, leading to more CO2 being pulled out of the atmosphere. Authors note that this process may be disrupted as the Southern Ocean may be too warm for the icebergs to travel far enough to trigger these changes or effects. A group of 17 high-ranking ecologists publish a perspective piece that reviews a number of studies that, based on current trends, indicate that future environmental conditions will be far more dangerous than currently believed, concluding that current challenges – themselves in specific – that humanity faces are large and underestimated. The small group cautions that such an "optimism bias" is prevalent and that fundamental changes are required, listing a few of such they consider adequate in the form of broad descriptions in their largely static document, published by a scientific journal. 15 January Researchers in China report the successful transmission of entangled photons between drones, used as nodes for the development of mobile quantum networks or flexible network extensions, marking the first work in which entangled particles were sent between two moving devices. Scientists from U.S. federal medical agencies report that gut infections increase its microbiota's resistance to subsequent infections and that this is associated with taurine, whose exogenous supply can induce this microbiota alteration. 17 January – LauncherOne becomes the first successful all-liquid-fuelled air-launched rocket to reach orbit. 20 January Archaeologists report the discovery of what may be earliest evidence of human use of symbols – a ~120-ky-old bone engraved with six lines. Researchers report that myeloid cells are drivers of a maladaptive inflammation element of brain-ageing in mice and that this can be reversed or prevented via inhibition of their EP2 signalling. Scientists report that the MOTS-c peptide in the mitochondrial genome is an AMPK-related regulator of age-dependent physical decline in mice and that its exogenous supply initiated in late-life can substantially increase their physical performance and healthspans. 22 January A study described as the "first long-term assessment of global bee decline", which analyzed GBIF-data of over a century, finds that the number of bee species declined steeply after the 1990s, shrinking by a quarter in 2006–2015 compared to before 1990. COVID-19 pandemic: Preliminary analyses indicate that the SARS-CoV-2 variant of concern detected in the U.K. is associated with an increased severity of disease.
25 January Global ice loss is found to be accelerating at a record rate in a scientific review, matching the worst-case scenarios of the IPCC. Astronomers report the discovery of TOI-178, a rare system of six exoplanets locked in a complex chain of Laplace orbital resonances and variations in the densities that are hard to explain. Australian scientists develop a new cryogenic computer system called Gooseberry, which has potential for scaling up quantum computers from dozens to thousands of qubits. 26 January – A study suggests that operating air purifiers or air ventilation systems in confined spaces during their occupancy by multiple people leads to increased airborne virus transmission due to air circulation effects. 27 January Researchers report a way to manufacture transparent wood, whose qualities exceed those made with the main process used earlier, that requires substantially less amounts of chemicals and energy – solar-assisted chemical brushing. Scientists report that shark and ray populations have fallen by 71% since 1970 as a result of human actions, primarily overfishing. 28 January COVID-19 pandemic: Medical scientists report the first detection of the SARS-CoV-2 Beta variant. Researchers report the development of a highly efficient single-photon source for quantum IT with a system of gated quantum dots in a tunable microcavity which captures photons released from these excited "artificial atoms".
February
2 February COVID-19 pandemic: Russia's Sputnik V vaccine is shown to be 92% effective against COVID-19, according to late stage trial results published in The Lancet. COVID-19 pandemic: Medical scientists in the United Kingdom report the detection of E484K (in 11 out of 214,000 samples), a mutation of the U.K. coronavirus variant that may compromise current vaccine effectiveness. Astronomers report that Tabby's Star, observed to dim in very unusual ways, has been found to be a binary stellar system. 5 February COVID-19 pandemic: A study suggests that climate change may have driven the emergence of SARS-CoV-2, by increasing the growth of forest habitats favoured by bats carrying the virus. A new theory aims to explain ʻOumuamua's peculiarities naturally and estimates, if true, ~4% of astronomical bodies in the interstellar medium to be N2 ice fragments. A study identifies genes for face shape and, for the first time, finds that a version of a gene – which was possibly selected for due to adaption to cold climate via fat distribution – is associated with a facial feature, lip thickness, and introgressed from ancient humans – Denisovans – into modern humans, Native Americans. Researchers demonstrate a first prototype of quantum-logic gates for distributed quantum computers. 8 February – Scientists report an updated status of studies considering the possible detection of lifeforms on Venus (via of phosphine) and Mars (via methane). 9 February The UAE's Hope spacecraft becomes the first Arabian mission to successfully enter orbit around Mars. A study using a high spatial resolution model and an updated concentration-response function finds that 10.2 million global excess deaths in 2012 and 8.7 million in 2018 – or – were due to air pollution generated by fossil fuel combustion, significantly higher than earlier estimates and with spatially subdivided mortality impacts. A study concludes that the rates of emissions reductions need to increase by 80% beyond NDCs to meet the 2°C upper target range of the Paris Agreement, that the probabilities of major emitters meeting their NDCs without such an increase is very low, estimating that with current trends the probability of staying below 2 °C of warming is 5% and if NDCs were met and continued post-2030 by all signatory systems 26%. A study finds that air pollution by nitrogen dioxide could be a technosignature by which one could detect extraterrestrial civilizations via "atmospheric SETI". 10 February The Chinese Tianwen-1 spacecraft successfully enters orbit around Mars. A journal-accepted preprint suggests observational data for a planet-mass object "Planet 9" at the outer Solar system is not significant and could be selection bias.