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For a topic outline of science, see Outline of science.
French Academy of Sciences

Members of the Academy in 1667 with Louis XIV

Science is a rigorous, systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the world. Modern science is typically divided into three major branches: natural sciences (e.g., physics, chemistry, and biology), which study the physical world; the social sciences (e.g., economics, psychology, and sociology), which study individuals and societies; and the formal sciences (e.g., logic, mathematics, and theoretical computer science), which study formal systems, governed by axioms and rules. There is disagreement whether the formal sciences are science disciplines, because they do not rely on empirical evidence. Applied sciences are disciplines that use scientific knowledge for practical purposes, such as in engineering and medicine.

The history of science spans the majority of the historical record, with the earliest written records of identifiable predecessors to modern science dating to Bronze Age Egypt and Mesopotamia from around 3000 to 1200 BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped the Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes, while further advancements, including the introduction of the Hindu–Arabic numeral system, were made during the Golden Age of India. Scientific research deteriorated in these regions after the fall of the Western Roman Empire during the early middle ages (400 to 1000 CE), but in the Medieval renaissances (Carolingian Renaissance, Ottonian Renaissance and the Renaissance of the 12th century) scholarship flourished again. Some Greek manuscripts lost in Western Europe were preserved and expanded upon in the Middle East during the Islamic Golden Age and later by the efforts of Byzantine Greek scholars who brought Greek manuscripts from the dying Byzantine Empire to Western Europe in the Renaissance.

The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived "natural philosophy", which was later transformed by the Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions. The scientific method soon played a greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape, along with the changing of "natural philosophy" to "natural science".

New knowledge in science is advanced by research from scientists who are motivated by curiosity about the world and a desire to solve problems. Contemporary scientific research is highly collaborative and is usually done by teams in academic and research institutions, government agencies, and companies. The practical impact of their work has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the ethical and moral development of commercial products, armaments, health care, public infrastructure, and environmental protection. (Full article...)

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  • Image 1 Pittakis, c. 1850 Kyriakos S. Pittakis (also Pittakys; Greek: Κυριακός Σ. Πιττάκης; 1798 – 4 November [O.S. 23 October] 1863) was a Greek archaeologist. He was the first Greek to serve as Ephor General of Antiquities, the head of the Greek Archaeological Service, in which capacity he carried out the conservation and restoration of several monuments on the Acropolis of Athens. He has been described as a "dominant figure in Greek archaeology for 27 years", and as "one of the most important epigraphers of the nineteenth century". Pittakis was largely self-taught as an archaeologist, and one of the few native Greeks active in the field during the late Ottoman period and the early years of the Kingdom of Greece. He played an influential role in the early years of the Greek Archaeological Service and was a founding member of the Archaeological Society of Athens, a private body which undertook the excavation, conservation and publication of archaeological finds. He was responsible for much of the early excavation and restoration of the Acropolis, including efforts to restore the Erechtheion, the Parthenon, the Temple of Athena Nike and the Propylaia. As ephor of the Central Public Museum for Antiquities from 1836, and later as Ephor General, he was largely responsible for the conservation and protection of many of the monuments and artefacts then known from Ancient Greece. (Full article...)

    Pittakis, c. 1850

    Kyriakos S. Pittakis (also Pittakys; Greek: Κυριακός Σ. Πιττάκης; 1798 – 4 November [O.S. 23 October] 1863) was a Greek archaeologist. He was the first Greek to serve as Ephor General of Antiquities, the head of the Greek Archaeological Service, in which capacity he carried out the conservation and restoration of several monuments on the Acropolis of Athens. He has been described as a "dominant figure in Greek archaeology for 27 years", and as "one of the most important epigraphers of the nineteenth century".

    Pittakis was largely self-taught as an archaeologist, and one of the few native Greeks active in the field during the late Ottoman period and the early years of the Kingdom of Greece. He played an influential role in the early years of the Greek Archaeological Service and was a founding member of the Archaeological Society of Athens, a private body which undertook the excavation, conservation and publication of archaeological finds. He was responsible for much of the early excavation and restoration of the Acropolis, including efforts to restore the Erechtheion, the Parthenon, the Temple of Athena Nike and the Propylaia. As ephor of the Central Public Museum for Antiquities from 1836, and later as Ephor General, he was largely responsible for the conservation and protection of many of the monuments and artefacts then known from Ancient Greece. (Full article...)
  • Image 2 Bottom view of the holotype specimen of O. kokomoensis recovered at Kokomo, in the United States Onychopterella (/ˌɒnɪkɒptəˈrɛlə/ ON-ə-kop-tə-REL-ə, from Ancient Greek: ὄνῠξ (ónyx), "claw", and πτερόν (pteron), "wing") is a genus of predatory eurypterid ("sea scorpion"), an extinct group of aquatic arthropods. Fossils of Onychopterella have been discovered in deposits from the Late Ordovician to the Late Silurian. The genus contains three species: O. kokomoensis, the type species, from the Early Pridoli epoch of Indiana; O. pumilus, from the Early Llandovery epoch of Illinois, both from the United States; and O. augusti, from the Late Hirnantian to Early Rhuddanian stages of South Africa. Its prosoma (head) could be subquadrate (almost square) or subrectangular (almost rectangular), with reniform (kidney-shaped) eyes. The appendages (limbs) were generally long and narrow with a spine on their tip. The abdomen and telson (the posteriormost division of the body) had different shapes and sizes depending on the species. The ornamentation of the body consisted of small, pointed scales. The largest species of the genus was O. kokomoensis with a total length of 16 centimetres (6.3 inches) long, followed by O. augusti (14.3 cm, 5.6 in) and O. pumilus (4 cm, 1.6 in). (Full article...)

    Bottom view of the holotype specimen of O. kokomoensis recovered at Kokomo, in the United States

    Onychopterella (/ˌɒnɪkɒptəˈrɛlə/ ON-ə-kop-tə-REL-ə, from Ancient Greek: ὄνῠξ (ónyx), "claw", and πτερόν (pteron), "wing") is a genus of predatory eurypterid ("sea scorpion"), an extinct group of aquatic arthropods. Fossils of Onychopterella have been discovered in deposits from the Late Ordovician to the Late Silurian. The genus contains three species: O. kokomoensis, the type species, from the Early Pridoli epoch of Indiana; O. pumilus, from the Early Llandovery epoch of Illinois, both from the United States; and O. augusti, from the Late Hirnantian to Early Rhuddanian stages of South Africa.

    Its prosoma (head) could be subquadrate (almost square) or subrectangular (almost rectangular), with reniform (kidney-shaped) eyes. The appendages (limbs) were generally long and narrow with a spine on their tip. The abdomen and telson (the posteriormost division of the body) had different shapes and sizes depending on the species. The ornamentation of the body consisted of small, pointed scales. The largest species of the genus was O. kokomoensis with a total length of 16 centimetres (6.3 inches) long, followed by O. augusti (14.3 cm, 5.6 in) and O. pumilus (4 cm, 1.6 in). (Full article...)
  • Image 3 Male in Okonjima, Namibia The lion (Panthera leo) is a large cat of the genus Panthera native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphic; adult male lions are larger than females and have a prominent mane. It is a social species, forming groups called prides. A lion's pride consists of a few adult males, related females, and cubs. Groups of female lions usually hunt together, preying mostly on large ungulates. The lion is an apex and keystone predator; although some lions scavenge when opportunities occur and have been known to hunt humans, lions typically do not actively seek out and prey on humans. The lion inhabits grasslands, savannahs and shrublands. It is usually more diurnal than other wild cats, but when persecuted, it adapts to being active at night and at twilight. During the Neolithic period, the lion ranged throughout Africa and Eurasia from Southeast Europe to India, but it has been reduced to fragmented populations in sub-Saharan Africa and one population in western India. It has been listed as Vulnerable on the IUCN Red List since 1996 because populations in African countries have declined by about 43% since the early 1990s. Lion populations are untenable outside designated protected areas. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are the greatest causes for concern. (Full article...)

    Male in Okonjima, Namibia

    The lion (Panthera leo) is a large cat of the genus Panthera native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphic; adult male lions are larger than females and have a prominent mane. It is a social species, forming groups called prides. A lion's pride consists of a few adult males, related females, and cubs. Groups of female lions usually hunt together, preying mostly on large ungulates. The lion is an apex and keystone predator; although some lions scavenge when opportunities occur and have been known to hunt humans, lions typically do not actively seek out and prey on humans.

    The lion inhabits grasslands, savannahs and shrublands. It is usually more diurnal than other wild cats, but when persecuted, it adapts to being active at night and at twilight. During the Neolithic period, the lion ranged throughout Africa and Eurasia from Southeast Europe to India, but it has been reduced to fragmented populations in sub-Saharan Africa and one population in western India. It has been listed as Vulnerable on the IUCN Red List since 1996 because populations in African countries have declined by about 43% since the early 1990s. Lion populations are untenable outside designated protected areas. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are the greatest causes for concern. (Full article...)
  • Image 4 The 1867 Manhattan earthquake struck Riley County, Kansas, in the United States on April 24, 1867, at 20:22 UTC, or about 14:30 local time. The strongest earthquake to originate in the state, it measured 5.1 on a seismic scale that is based on an isoseismal map or the event's felt area. The earthquake's epicenter was near the town of Manhattan. The earthquake had a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. It caused minor damage, reports of which were confined to Kansas, Iowa, and Missouri, according to the United States Geological Survey. Felt over an area of 200,000 square miles (520,000 km2), the earthquake reached the states of Indiana, Illinois, and possibly Ohio, though the latter reports have been questioned. (Full article...)

    The 1867 Manhattan earthquake struck Riley County, Kansas, in the United States on April 24, 1867, at 20:22 UTC, or about 14:30 local time. The strongest earthquake to originate in the state, it measured 5.1 on a seismic scale that is based on an isoseismal map or the event's felt area. The earthquake's epicenter was near the town of Manhattan.

    The earthquake had a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. It caused minor damage, reports of which were confined to Kansas, Iowa, and Missouri, according to the United States Geological Survey. Felt over an area of 200,000 square miles (520,000 km2), the earthquake reached the states of Indiana, Illinois, and possibly Ohio, though the latter reports have been questioned. (Full article...)
  • Image 5 Chicado V (1950 – February 1972) was a Champion Quarter Horse racehorse foaled (born) in 1950, and considered one of the outstanding broodmares of her breed. She was bred by Frank Vessels of Los Alamitos, California, and trained by Earl Holmes. Chicado V started only six times because knee problems cut short her racing career. However, she won her first two starts while breaking or equaling track records, and was given the title of co-Champion Quarter Running Two-Year-Old Filly by the American Quarter Horse Association (AQHA) in 1952. The next year she ran her last four races, winning once and setting one more speed record. After her last race, in December 1953, she was retired from the track to become a broodmare, and had nine foals. Two of her offspring were named Champion Quarter Running Horses, and all her foals had a total of seven stakes race wins. One of her daughters, Table Tennis, went on to become a noted broodmare herself, as did Table Tennis' daughter Rapid Volley and granddaughter Perks. However, three of Chicado V's sons—Triple Chick, Three Chicks, and The Ole Man—were her best-known offspring; all three became leading sires and are the main cause of her fame. She was inducted into the AQHA's American Quarter Horse Hall of Fame in 2006. (Full article...)
    Chicado V (1950 – February 1972) was a Champion Quarter Horse racehorse foaled (born) in 1950, and considered one of the outstanding broodmares of her breed. She was bred by Frank Vessels of Los Alamitos, California, and trained by Earl Holmes.

    Chicado V started only six times because knee problems cut short her racing career. However, she won her first two starts while breaking or equaling track records, and was given the title of co-Champion Quarter Running Two-Year-Old Filly by the American Quarter Horse Association (AQHA) in 1952. The next year she ran her last four races, winning once and setting one more speed record. After her last race, in December 1953, she was retired from the track to become a broodmare, and had nine foals. Two of her offspring were named Champion Quarter Running Horses, and all her foals had a total of seven stakes race wins. One of her daughters, Table Tennis, went on to become a noted broodmare herself, as did Table Tennis' daughter Rapid Volley and granddaughter Perks. However, three of Chicado V's sons—Triple Chick, Three Chicks, and The Ole Man—were her best-known offspring; all three became leading sires and are the main cause of her fame. She was inducted into the AQHA's American Quarter Horse Hall of Fame in 2006. (Full article...)
  • Image 6 Banksia spinulosa var. spinulosa, Georges River National Park Banksia spinulosa, the hairpin banksia, is a species of woody shrub, of the genus Banksia in the family Proteaceae, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also clay soils. It generally grows as a small shrub to 2 metres (7 ft) in height, though can be a straggly tree to 6 metres (20 ft). It has long narrow leaves with inflorescences which can vary considerably in coloration; while the spikes are gold or less commonly yellowish, the emergent styles may be a wide range of colours – from black, purple, red, orange or yellow. Banksia spinulosa was named by James Edward Smith in England in 1793, after being collected by John White, most likely in 1792. He gave it the common name prickly-leaved banksia, though this has fallen out of use. With four currently recognised varieties, the species has had a complicated taxonomic history, with two varieties initially described as separate species in the early 19th century. A fourth, from the New England region, has only recently been described. However, there has been disagreement whether one, var. cunninghamii, is distinct enough to once again have specific status. The pre-eminent authority on Banksia, Alex George, concedes there is still more work to be done on the Banksia spinulosa complex. (Full article...)

    Banksia spinulosa var. spinulosa,
    Georges River National Park

    Banksia spinulosa, the hairpin banksia, is a species of woody shrub, of the genus Banksia in the family Proteaceae, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also clay soils. It generally grows as a small shrub to 2 metres (7 ft) in height, though can be a straggly tree to 6 metres (20 ft). It has long narrow leaves with inflorescences which can vary considerably in coloration; while the spikes are gold or less commonly yellowish, the emergent styles may be a wide range of colours – from black, purple, red, orange or yellow.

    Banksia spinulosa was named by James Edward Smith in England in 1793, after being collected by John White, most likely in 1792. He gave it the common name prickly-leaved banksia, though this has fallen out of use. With four currently recognised varieties, the species has had a complicated taxonomic history, with two varieties initially described as separate species in the early 19th century. A fourth, from the New England region, has only recently been described. However, there has been disagreement whether one, var. cunninghamii, is distinct enough to once again have specific status. The pre-eminent authority on Banksia, Alex George, concedes there is still more work to be done on the Banksia spinulosa complex. (Full article...)
  • Image 7 Bald eagle preparing to fly at Kachemak Bay, Alaska, United States The bald eagle (Haliaeetus leucocephalus) is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (Haliaeetus albicilla), which occupies the same niche as the bald eagle in the Palearctic. Its range includes most of Canada and Alaska, all of the contiguous United States, and northern Mexico. It is found near large bodies of open water with an abundant food supply and old-growth trees for nesting. The bald eagle is an opportunistic feeder which subsists mainly on fish, which it swoops down upon and snatches from the water with its talons. It builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal species, up to 4 m (13 ft) deep, 2.5 m (8.2 ft) wide, and 1 metric ton (1.1 short tons) in weight. Sexual maturity is attained at the age of four to five years. (Full article...)

    Bald eagle preparing to fly at Kachemak Bay, Alaska, United States

    The bald eagle (Haliaeetus leucocephalus) is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a species pair with the white-tailed eagle (Haliaeetus albicilla), which occupies the same niche as the bald eagle in the Palearctic. Its range includes most of Canada and Alaska, all of the contiguous United States, and northern Mexico. It is found near large bodies of open water with an abundant food supply and old-growth trees for nesting.

    The bald eagle is an opportunistic feeder which subsists mainly on fish, which it swoops down upon and snatches from the water with its talons. It builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal species, up to 4 m (13 ft) deep, 2.5 m (8.2 ft) wide, and 1 metric ton (1.1 short tons) in weight. Sexual maturity is attained at the age of four to five years. (Full article...)
  • Image 8 A view of the MCVF, with Mount Cayley obscured by clouds on the left. Mount Fee is the relatively small jagged peak to the far right. The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the MCVF volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, a volcanic peak located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains. Eruptions along the length of the MCVF began between 1.6 and 5.3 million years ago. At least 23 eruptions have occurred throughout its eruptive history. This volcanic activity ranged from effusive to explosive, with magma compositions ranging from basaltic to rhyolitic. Because the MCVF has a high elevation and consists of a cluster of mostly high altitude, non-overlapping volcanoes, subglacial activity is likely to have occurred under less than 800 m (2,600 ft) of glacial ice. The style of this glaciation promoted meltwater escape during eruptions. The steep profile of the volcanic field and its subglacial landforms support this hypothesis. As a result, volcanic features in the MCVF that interacted with glacial ice lack rocks that display evidence of abundant water during eruption, such as hyaloclastite and pillow lava. (Full article...)

    A view of the MCVF, with Mount Cayley obscured by clouds on the left. Mount Fee is the relatively small jagged peak to the far right.

    The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the MCVF volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, a volcanic peak located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.

    Eruptions along the length of the MCVF began between 1.6 and 5.3 million years ago. At least 23 eruptions have occurred throughout its eruptive history. This volcanic activity ranged from effusive to explosive, with magma compositions ranging from basaltic to rhyolitic. Because the MCVF has a high elevation and consists of a cluster of mostly high altitude, non-overlapping volcanoes, subglacial activity is likely to have occurred under less than 800 m (2,600 ft) of glacial ice. The style of this glaciation promoted meltwater escape during eruptions. The steep profile of the volcanic field and its subglacial landforms support this hypothesis. As a result, volcanic features in the MCVF that interacted with glacial ice lack rocks that display evidence of abundant water during eruption, such as hyaloclastite and pillow lava. (Full article...)
  • Image 9 Tumbler Ridge is a district municipality in the foothills of the B.C. Rockies in northeastern British Columbia, Canada, and a member municipality of the Peace River Regional District. With a population of 2,399 (2021) living in a townsite, the municipality encompasses an area of 1,558 km2 (602 sq mi) of mostly Crown land. The townsite is located near the confluence of the Murray River and Flatbed Creek and the intersection of Highway 52 and Highway 29 and includes the site of the Tumbler Ridge Secondary School and Tumbler Ridge Airport. It is part of the Peace River South provincial electoral district and the Prince George—Peace River—Northern Rockies federal riding. Tumbler Ridge is a planned community with the housing and infrastructure construct built simultaneously in 1981 by the provincial government to service the coal industry as part of the British Columbia Resources Investment Corporation's Northeast Coal Development. In 1981, a consortium of Japanese steel mills agreed to purchase 100 million tonnes of coal over 15 years for US$7.5 billion from two mining companies, Denison Mines Inc. and the Teck Corporation, who were to operate the Quintette mine and the Bullmoose mine respectively. Declining global coal prices after 1981, and weakening Asian markets in the late 1990s, made the town's future uncertain and kept it from achieving its projected population of 10,000 people. The uncertainty dissuaded investment and kept the economy from diversifying. When price reductions were forced onto the mines, the Quintette mine was closed in 2000 production and the town lost about half its population. Coal prices began to rise after the turn of the century, leading to the opening of the Peace River Coal Trend mine by Northern Energy & Mining Inc. (now owned by Anglo American Met Coal) and the Wolverine Mine, originally owned by Western Canadian Coal, which was purchased by Walter Energy in 2010. Walter went bankrupt in 2015, and their Canadian assets—including the Wolverine Mine—were purchased by Conuma Coal in 2016. (Full article...)
    Tumbler Ridge is a district municipality in the foothills of the B.C. Rockies in northeastern British Columbia, Canada, and a member municipality of the Peace River Regional District. With a population of 2,399 (2021) living in a townsite, the municipality encompasses an area of 1,558 km2 (602 sq mi) of mostly Crown land. The townsite is located near the confluence of the Murray River and Flatbed Creek and the intersection of Highway 52 and Highway 29 and includes the site of the Tumbler Ridge Secondary School and Tumbler Ridge Airport. It is part of the Peace River South provincial electoral district and the Prince George—Peace River—Northern Rockies federal riding.

    Tumbler Ridge is a planned community with the housing and infrastructure construct built simultaneously in 1981 by the provincial government to service the coal industry as part of the British Columbia Resources Investment Corporation's Northeast Coal Development. In 1981, a consortium of Japanese steel mills agreed to purchase 100 million tonnes of coal over 15 years for US$7.5 billion from two mining companies, Denison Mines Inc. and the Teck Corporation, who were to operate the Quintette mine and the Bullmoose mine respectively. Declining global coal prices after 1981, and weakening Asian markets in the late 1990s, made the town's future uncertain and kept it from achieving its projected population of 10,000 people. The uncertainty dissuaded investment and kept the economy from diversifying. When price reductions were forced onto the mines, the Quintette mine was closed in 2000 production and the town lost about half its population. Coal prices began to rise after the turn of the century, leading to the opening of the Peace River Coal Trend mine by Northern Energy & Mining Inc. (now owned by Anglo American Met Coal) and the Wolverine Mine, originally owned by Western Canadian Coal, which was purchased by Walter Energy in 2010. Walter went bankrupt in 2015, and their Canadian assets—including the Wolverine Mine—were purchased by Conuma Coal in 2016. (Full article...)
  • Image 10 Galileo image of 243 Ida. The dot to the right is its moon Dactyl. Ida, minor planet designation 243 Ida, is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mythology. Later telescopic observations categorized Ida as an S-type asteroid, the most numerous type in the inner asteroid belt. On 28 August 1993, Ida was visited by the uncrewed Galileo spacecraft while en route to Jupiter. It was the second asteroid visited by a spacecraft and the first found to have a natural satellite. Ida's orbit lies between the planets Mars and Jupiter, like all main-belt asteroids. Its orbital period is 4.84 years, and its rotation period is 4.63 hours. Ida has an average diameter of 31.4 km (19.5 mi). It is irregularly shaped and elongated, apparently composed of two large objects connected together. Its surface is one of the most heavily cratered in the Solar System, featuring a wide variety of crater sizes and ages. (Full article...)

    Galileo image of 243 Ida. The dot to the right is its moon Dactyl.

    Ida, minor planet designation 243 Ida, is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mythology. Later telescopic observations categorized Ida as an S-type asteroid, the most numerous type in the inner asteroid belt. On 28 August 1993, Ida was visited by the uncrewed Galileo spacecraft while en route to Jupiter. It was the second asteroid visited by a spacecraft and the first found to have a natural satellite.

    Ida's orbit lies between the planets Mars and Jupiter, like all main-belt asteroids. Its orbital period is 4.84 years, and its rotation period is 4.63 hours. Ida has an average diameter of 31.4 km (19.5 mi). It is irregularly shaped and elongated, apparently composed of two large objects connected together. Its surface is one of the most heavily cratered in the Solar System, featuring a wide variety of crater sizes and ages. (Full article...)
  • Image 11 Huaynaputina (/ˌwaɪnəpʊˈtiːnə/ WY-nə-puu-TEE-nə; Spanish: [wajnapuˈtina]) is a volcano in a volcanic high plateau in southern Peru. Lying in the Central Volcanic Zone of the Andes, it was formed by the subduction of the oceanic Nazca Plate under the continental South American Plate. Huaynaputina is a large volcanic crater, lacking an identifiable mountain profile, with an outer stratovolcano and three younger volcanic vents within an amphitheatre-shaped structure that is either a former caldera or a remnant of glacial erosion. The volcano has erupted dacitic magma. In the Holocene, Huaynaputina has erupted several times, including on 19 February 1600 – the largest eruption ever recorded in South America – which continued with a series of events into March. Witnessed by people in the city of Arequipa, it killed at least 1,000–1,500 people in the region, wiped out vegetation, buried the surrounding area with 2 metres (7 ft) of volcanic rock and damaged infrastructure and economic resources. The eruption had a significant impact on Earth's climate, causing a volcanic winter: temperatures in the Northern Hemisphere decreased; cold waves hit parts of Europe, Asia and the Americas; and the climate disruption may have played a role in the onset of the Little Ice Age. Floods, famines, and social upheavals resulted, including a probable link with the Russian Time of Troubles. This eruption has been computed to measure 6 on the Volcanic Explosivity Index (VEI). (Full article...)
    Huaynaputina (/ˌwaɪnəpʊˈtiːnə/ WY-nə-puu-TEE-nə; Spanish: [wajnapuˈtina]) is a volcano in a volcanic high plateau in southern Peru. Lying in the Central Volcanic Zone of the Andes, it was formed by the subduction of the oceanic Nazca Plate under the continental South American Plate. Huaynaputina is a large volcanic crater, lacking an identifiable mountain profile, with an outer stratovolcano and three younger volcanic vents within an amphitheatre-shaped structure that is either a former caldera or a remnant of glacial erosion. The volcano has erupted dacitic magma.

    In the Holocene, Huaynaputina has erupted several times, including on 19 February 1600 – the largest eruption ever recorded in South America – which continued with a series of events into March. Witnessed by people in the city of Arequipa, it killed at least 1,000–1,500 people in the region, wiped out vegetation, buried the surrounding area with 2 metres (7 ft) of volcanic rock and damaged infrastructure and economic resources. The eruption had a significant impact on Earth's climate, causing a volcanic winter: temperatures in the Northern Hemisphere decreased; cold waves hit parts of Europe, Asia and the Americas; and the climate disruption may have played a role in the onset of the Little Ice Age. Floods, famines, and social upheavals resulted, including a probable link with the Russian Time of Troubles. This eruption has been computed to measure 6 on the Volcanic Explosivity Index (VEI). (Full article...)
  • Image 12 Alan Shepard and the American flag on the Moon, Apollo 14, February 1971 (photo by Edgar Mitchell) Apollo 14 (January 31 – February 9, 1971) was the eighth crewed mission in the United States Apollo program, the third to land on the Moon, and the first to land in the lunar highlands. It was the last of the "H missions", landings at specific sites of scientific interest on the Moon for two-day stays with two lunar extravehicular activities (EVAs or moonwalks). The mission was originally scheduled for 1970, but was postponed because of the investigation following the failure of Apollo 13 to reach the Moon's surface, and the need for modifications to the spacecraft as a result. Commander Alan Shepard, Command Module Pilot Stuart Roosa, and Lunar Module Pilot Edgar Mitchell launched on their nine-day mission on Sunday, January 31, 1971, at 4:03:02 p.m. EST. En route to the lunar landing, the crew overcame malfunctions that might have resulted in a second consecutive aborted mission, and possibly, the premature end of the Apollo program. (Full article...)

    Alan Shepard and the American flag on the Moon, Apollo 14, February 1971 (photo by Edgar Mitchell)

    Apollo 14 (January 31 – February 9, 1971) was the eighth crewed mission in the United States Apollo program, the third to land on the Moon, and the first to land in the lunar highlands. It was the last of the "H missions", landings at specific sites of scientific interest on the Moon for two-day stays with two lunar extravehicular activities (EVAs or moonwalks).

    The mission was originally scheduled for 1970, but was postponed because of the investigation following the failure of Apollo 13 to reach the Moon's surface, and the need for modifications to the spacecraft as a result. Commander Alan Shepard, Command Module Pilot Stuart Roosa, and Lunar Module Pilot Edgar Mitchell launched on their nine-day mission on Sunday, January 31, 1971, at 4:03:02 p.m. EST. En route to the lunar landing, the crew overcame malfunctions that might have resulted in a second consecutive aborted mission, and possibly, the premature end of the Apollo program. (Full article...)
  • Image 13 Reconstruction by Jacob Hägg, 1909 Kronan, also called Stora Kronan, was a Swedish warship that served as the flagship of the Swedish Navy in the Baltic Sea in the 1670s. When built, she was one of the largest seagoing vessels in the world. The construction of Kronan lasted from 1668 to 1672 and was delayed by difficulties with financing and conflicts between the shipwright Francis Sheldon and the Swedish admiralty. After four years of service, the ship foundered in rough weather at the Battle of Öland on 1 June 1676: while making a sharp turn under too much sail she capsized, and the gunpowder magazine ignited and blew off most of the bow. Kronan sank quickly, taking about 800 men and more than 100 guns with her, along with valuable military equipment, weapons, personal items, and large quantities of silver and gold coins. The loss of Kronan was a hard blow for Sweden during the Scanian War. Besides being the largest and most heavily armed ship in the Swedish Navy, she had been an important status symbol for the monarchy of the young Charles XI. Along with Kronan, the navy lost a sizeable proportion of its best manpower, acting supreme commander Lorentz Creutz, numerous high-ranking fleet officers, and the chief of the navy medical staff. A commission was set up to investigate whether any individuals could be held responsible for the defeat at the Battle of Öland and other major defeats during the war. (Full article...)

    A black and white drawing of a large sailing warship seen from behind and to the right
    Reconstruction by Jacob Hägg, 1909

    Kronan, also called Stora Kronan, was a Swedish warship that served as the flagship of the Swedish Navy in the Baltic Sea in the 1670s. When built, she was one of the largest seagoing vessels in the world. The construction of Kronan lasted from 1668 to 1672 and was delayed by difficulties with financing and conflicts between the shipwright Francis Sheldon and the Swedish admiralty. After four years of service, the ship foundered in rough weather at the Battle of Öland on 1 June 1676: while making a sharp turn under too much sail she capsized, and the gunpowder magazine ignited and blew off most of the bow. Kronan sank quickly, taking about 800 men and more than 100 guns with her, along with valuable military equipment, weapons, personal items, and large quantities of silver and gold coins.

    The loss of Kronan was a hard blow for Sweden during the Scanian War. Besides being the largest and most heavily armed ship in the Swedish Navy, she had been an important status symbol for the monarchy of the young Charles XI. Along with Kronan, the navy lost a sizeable proportion of its best manpower, acting supreme commander Lorentz Creutz, numerous high-ranking fleet officers, and the chief of the navy medical staff. A commission was set up to investigate whether any individuals could be held responsible for the defeat at the Battle of Öland and other major defeats during the war. (Full article...)
  • Image 14 Greater crested tern in first-year plumage Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of eleven genera. They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap to the head, but the marsh terns, the Inca tern, and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap. Terns are long-lived birds and are relatively free from natural predators and parasites; most species are declining in numbers due directly or indirectly to human activities, including habitat loss, pollution, disturbance, and predation by introduced mammals. The Chinese crested tern is in a critical situation and three other species are classed as endangered. International agreements provide a measure of protection, but adults and eggs of some species are still used for food in the tropics. The eggs of two species are eaten in the West Indies because they are believed to have aphrodisiac properties. (Full article...)

    Greater crested tern in first-year plumage

    Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of eleven genera. They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap to the head, but the marsh terns, the Inca tern, and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap.

    Terns are long-lived birds and are relatively free from natural predators and parasites; most species are declining in numbers due directly or indirectly to human activities, including habitat loss, pollution, disturbance, and predation by introduced mammals. The Chinese crested tern is in a critical situation and three other species are classed as endangered. International agreements provide a measure of protection, but adults and eggs of some species are still used for food in the tropics. The eggs of two species are eaten in the West Indies because they are believed to have aphrodisiac properties. (Full article...)
  • Image 15 Banksia petiolaris is a rare species of flowering plant in the family Proteaceae native to Western Australia, where it is found in sandy soils in the south coastal regions from Munglinup east to Israelite Bay. It was first described by Victorian state botanist Ferdinand von Mueller in 1864, and no subspecies are recognised. B.  petiolaris is one of several closely related species that will all grow as prostrate shrubs, with horizontal stems and thick, leathery upright leaves. Those of this species can be viable for up to 13 years—the longest-lived of any flowering plant recorded. It bears yellow cylindrical flower spikes, known as inflorescences, up to 16 cm (6+1⁄4 in) high in spring. As the spikes age, they turn grey and develop up to 20 woody seed pods, known as follicles, each. Insects such as bees, wasps and even ants can pollinate the flowers. B. petiolaris is nonlignotuberous, meaning it regenerates by seed after bushfire. B. petiolaris adapts readily to cultivation, growing in well-drained sandy soils in sunny locations. It is suitable for rockeries and as a groundcover. (Full article...)

    Banksia petiolaris is a rare species of flowering plant in the family Proteaceae native to Western Australia, where it is found in sandy soils in the south coastal regions from Munglinup east to Israelite Bay. It was first described by Victorian state botanist Ferdinand von Mueller in 1864, and no subspecies are recognised. B.  petiolaris is one of several closely related species that will all grow as prostrate shrubs, with horizontal stems and thick, leathery upright leaves. Those of this species can be viable for up to 13 years—the longest-lived of any flowering plant recorded. It bears yellow cylindrical flower spikes, known as inflorescences, up to 16 cm (6+1⁄4 in) high in spring. As the spikes age, they turn grey and develop up to 20 woody seed pods, known as follicles, each.

    Insects such as bees, wasps and even ants can pollinate the flowers. B. petiolaris is nonlignotuberous, meaning it regenerates by seed after bushfire. B. petiolaris adapts readily to cultivation, growing in well-drained sandy soils in sunny locations. It is suitable for rockeries and as a groundcover. (Full article...)
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The Hubble Space Telescope (HST) is a telescope in orbit around the Earth, named after astronomer Edwin Hubble for his discovery of galaxies outside the Milky Way and his creation of Hubble's law, which calculates the rate at which the universe is expanding. Its position outside the Earth's atmosphere allows it to take sharp optical images of very faint objects, and since its launch in 1990, it has become one of the most important instruments in the history of astronomy. It has been responsible for many ground-breaking observations and has helped astronomers achieve a better understanding of many fundamental problems in astrophysics. Hubble's Ultra-Deep Field is the deepest (most sensitive) astronomical optical image ever taken.

Selected biography

A stamp of Zhang Heng issued by China Post in 1955
Zhang Heng (Chinese: 張衡; AD 78–139), formerly romanized as Chang Heng, was a Chinese polymathic scientist and statesman who lived during the Han dynasty. Educated in the capital cities of Luoyang and Chang'an, he achieved success as an astronomer, mathematician, seismologist, hydraulic engineer, inventor, geographer, cartographer, ethnographer, artist, poet, philosopher, politician, and literary scholar.

Zhang applied his extensive knowledge of mechanics and gears in several of his inventions. He invented the world's first water-powered armillary sphere to assist astronomical observation; improved the inflow water clock by adding another tank; and invented the world's first seismoscope, which discerned the cardinal direction of an earthquake 500 km (310 mi) away. He improved previous Chinese calculations for pi. In addition to documenting about 2,500 stars in his extensive star catalog, Zhang also posited theories about the Moon and its relationship to the Sun: specifically, he discussed the Moon's sphericity, its illumination by reflected sunlight on one side and the hidden nature of the other, and the nature of solar and lunar eclipses. His fu (rhapsody) and shi poetry were renowned in his time and studied and analyzed by later Chinese writers. Zhang received many posthumous honors for his scholarship and ingenuity; some modern scholars have compared his work in astronomy to that of the Greco-Roman Ptolemy (AD 86–161).

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Further information: 2023 in science
24 November 2023 –
Astronomers at the Telescope Array Project in Utah, United States, observe the second largest cosmic ray ever detected, the so-called Amaterasu particle, with an energy of 244 EeV. (Cosmos Magazine)
2 November 2023 –
Colombian Environment Minister Susana Muhamad announces plans to sterilize 20 of 166 hippopotamuses, descendants of those imported by drug lord Pablo Escobar, and cull some others, citing environmental concerns. (AFP via ABS-CBN News)
30 October 2023 –
In a study published in Nature Geoscience, researchers suggest that solid particulates (predominantly silicate) from the Chicxulub asteroid impact played a dominant role in the radiative forcing leading to the Cretaceous–Paleogene extinction event (impact winter), contrary to the widely accepted theory that sulfur aerosols led to the mass extinction. (AFP via RFI) (Nature)
23 October 2023 – 2023 in arthropod paleontology
A new species of prehistoric millipede named Lauravolsella willemeni is discovered in the Netherlands. (NOS)
4 October 2023 –
Moungi Bawendi, Louis E. Brus, and Alexey Ekimov are awarded the Nobel Prize in Chemistry for their work on quantum dots. (BBC News)
3 October 2023 –
Pierre Agostini, Ferenc Krausz, and Anne L'Huillier are awarded the Nobel Prize in Physics for experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter. (The Guardian)

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