3I/Atlas: Third interstellar comet discovered.

On Tuesday 1 July 2025 scientists at the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile, observed a body 4.53 AU from the Sun (i.e. 4.53 times as far from the Sun as the planet Earth) between the constellations of Serpens Cauda and Sagittarius, which was given the provisional designation A11pl3Z. This object was travelling towards the Inner Solar System at a speed of 65 km per second, on what appeared to be a more-or-less straight trajectory, highly unusual in a body orbiting the Sun.

Discovery images for object A11pl3Z. ATLAS/University of Hawaii/NASA/Wikipedia.

A series of follow-up observations  by both professional and amateur astronomers confirmed that the body was a comet on a hyperbolic trajectory (a trajectory which will take it straight through the Solar System and out into interstellar space. Most such parabolic comets derive from the Oort Cloud, a vast disc of thinly spread cometary bodies between 2000 and 200 000 from the Sun. These comets are knocked from their orbits be close encounters with other bodies, plunge through the Inner Solar System once, then vanish into the depths of space. However, two previous comets have been found to be on trajectories which cannot be explained in this way, these being 1I/‘Oumuamua and 2I/Borisov, and on Tuesday 2 July it was confirmed that A11pl3Z was a third such body, leading to it being given the designation 3I/Atlas, in which the 'I' stands for 'Interstellar body', the '3' indicates that it was the third such body discovered, and 'ATLAS' refers to the ATLAS asteroid impact early warning system, which discovered the object.

The trajectory and current position (on 5 July 2025) of interstellar comet 3I/ATLAS. The Sky Live.

3I/ATLAS is predicted to reach its perihelion (closest point on its trajectory to the Sun) on 29 October 2025, when it will be 1.36 AU from the Sun. It will make its closet approach to the Earth on 19 December, when it will be 1.80 AU from us. Unfortunately, these events will happen while the comet is on the far side of the Sun, preventing observations during this period. The comet will pass the planet Mars at a distance of 0.19 AU on 3 October, and Jupiter at 0.38 AU on 16 March 2026. 3I/ATLAS is apparently a weekly active comet with an absolute magnitude of about 12 (a measure of its brightness), which implies a nucleus with a diameter of 3-5 km.

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Necrosyrtes monachus: Mass death of Hooded Vultures reported in The Gambia.

A mass death event affecting Hooded Vultures, Necrosyrtes monachus, has occurred in the town of Gunjur, in Kombo South District, The Gambia, according to the West African Bird Study Association. The association was contacted by local residents at 11.00  am local time on Thursday 3 July 2025, by local residents concerned by the sight of a large number of dead and dying Birds. When a team of researchers led by Fagimba Camara arrived at the site, they found 23 dead Vultures and a 24th in a sick and distressed condition.

A researcher from the West African Bird Study Association collecting dead Hooded Vultures, Necrosyrtes monachus, in Gunjur, The Gambia, following a mass death event on Thursday 3 July 2025. West African Bird Study Association.

Hooded Vultures are classed as Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. There are thought to be around 131 000 adult Hooded Vultures alive, spread across 45 African countries. However, the species is estimated to have suffered a 68% population decline in three generations, and sudden population collapses have been recorded in several countries, including Côte d’Ivoire, Togo, Benin, Ghana, Nigeria, Kenya, and Botswana, and illegal killings of Birds have been recorded in several countries, including Guinea Bissau, Burkina Faso, and The Gambia.

The current distribution and conservation status of the Hooded Vulture, Necrosyrtes monachus. International Union for the Conservation of Nature.

The researchers from the West African Bird Study Association have collected samples from the Gunjur Vultures for analysis, but it is thought most likely that the Birds have died as a result of poisoning. This is the most common cause of mass deaths among Vultures, not because they are targeted themselves, but because they will eat both bait put out for large predators which target livestock (itself an illegal activity in almost all countries), as well as the bodies of other Animals which have been poisoned, intentionally or otherwise.

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Eupholidoptera stelae: A new species of Bush Cricket from Cyprus.

Bush Crickets of the genus Eupholidoptera are found around the Mediterranean Basin from southern France to Turkey and the Levant. There are currently 55 known species, mostly with very limited distributions. The maximum diversity in the genus has been recorded from Greece (26 species) and Turkey (21 species). The cryptic habits of these Crickets, which are almost entirely nocturnal and mostly live in dense thorn-scrub, means that new species are still being discovered fairly regularly. The standard method of sampling Orthopterans, capture by hand, is difficult with cryptic groups such as Eupholidoptera, but members of the genus have been captured in baited pit traps set for Spiders and Beetles, which offers an alternative way to study the group.

In a paper published in the journal Zootaxa on 26 June 2025, Luc Willemse of the Naturalis Biodiversity Center, Christodoulos Makris of Lemesós on Cyprus, and Baudewijn Odé of Plasmolen in the Netherlands, describe a new species of Eupholidoptera from the Troodos Massif.of Cyprus.

The new species is named Eupholidoptera stelae in honour of Stela Makris, the daughter of Christodoulos Makris. It is described from a series of specimens obtained from baited traps and 'wine ropes' (ropes made from absorbent material which has been soaked in a mixture of vinagar and sugar and draped over shrubs and bushes - a method used primarily to capture Moths) in the Cedar and maquis forests of the Troodos Massif of Cyprus.

Eupholidoptera stelae field images. (1) Female Cedar Valley 07/09/2021 on a ‘wine rope’; (2) female Kannoures 23/08/2019; (3) male Kannoures 21/09/2019; (4) male Kannoures 21/09/2019. Christodoulos Makris in Willemse et al. (2025).

Female specimens are, on average, slightly larger than males, measuring between 17.4 and 21.4 mm, compared to between 16.2 and 19.5 mm in males. They are maroon in colour, alternated with some yellowish and blackish parts, a shade of green is visible on the legs. In females the proximal edge of the last abdominal tergite is black.

Eupholidoptera stelae is found at altitudes of 525 m–1515 m in the central and south-western part of the Troodos Massif of Cyprus, a landscape dominated by open Pine and Oak forests. The area of available habitat appears to be over 1000 km², and while it has only been detected in an area of about 24 km², it is difficult to detect and could be more widespread. This area receives a high number of tourist visits, but falls mostly within a series of national reserves, and is largely protected from development. For this reason, Willemse et al. do not believe that Eupholidoptera stelae needs to be included on the International Union for the Conservation of Nature's Red List of Threatened Species.

Habitats of Eupholidoptera stelae. (250 The central and south-western part of Troodos Massif. (26) Open Black Pine, Pinus nigra, forest with an undergrowth of Golden Oak, Quercus alnifolia, Grecian Whitebeam, Sorbus graeca and Holy Bramble, Rubus sanctus, in the Kannoures area of the Troodos Mountains,  (27)  Cedar  forest  with  the  endemics Cyprus Cedar, Cedrus  brevifolia,  and Golden Oak, Quercus  alnifolia,  in the Tripilos  area  of  Pafos  Forest,  (28) Shrubs including the endemic Golden Oak,  Quercus alnifolia, in Turkish Pine, Pinus brutia, forest. Christodoulos Makris in Willemse et al. (2025).

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The Earth approaches aphelion.

The Earth will reach its aphelion, the furthest point in its orbit from the Sun, a distance of 1.017 AU (1.017 times the average distance between the Earth and the Sun) or 152 141 035 km, at 7.55 pm GMT on Thursday 3 July 2025. The Earth's orbit is slightly eccentric and slightly variable, leading to the distance between the Earth and the Sun varying by about 3.4% over time, reaching aphelion early in July each year and perihelion (the closest point on its orbit to the Sun) early in January. The exact distance at aphelion and perihelion each year varies, with this year's aphelion being slightly further from the Sun than last year (2024), when the Earth reached 152 099 970 km from the Sun on Friday 5 July, or next year, when it will only reacha distance of 152 087 778 km on Monday 6 July.

The difference between the Earth's perihelion (closest point to the Sun) and aphelion (furthest point from the Sun). Time and Date.

This is counter intuitive to inhabitants of the Earth's Northern Hemisphere, who often assume that the Earth is closest to the Sun in midsummer, when in fact it is at its furthest away. This is because the tilt of the Earth plays a far greater role in our seasons than the distance from the Sun, and the Northern Hemisphere has just passed its Summer Solstice, i.e. the point at which the North Pole was pointing as close to the Sun as it ever gets, so that the Northern Hemisphere is currently getting much more sunlight than the Southern. The Earth's surface receives about 7% less sunlight at aphelion to at perihelion, but this is far less than the seasonal variation caused by the tilt of the Earth (23% in each hemisphere).

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Ptychognathus dajie: A new species of Pom Pom Crab from East and Southeast Asia.

The genus Ptychognathus comprises 32 species of brackish-water Crabs found in estuaries and the lower parts of river systems across the Indo-Western Pacific region. They are known as Pom Pom Crabs in the aquarium industry because of the clusters of fine setae (hairs) on their claws (although they are widely traded as freshwater Crabs rather than brackish-water Crabs). Most species of Ptychognathus have very localised distributions, being found on a single island, estuary, or river system, although one species, Ptychognathus barbatus, is found over an extremely wide area, including Japan, Taiwan, China, the Philippines, Malaysia, Indonesia, and New Caledonia. However, as part of a PhD thesis completed in 2006, carcinologist Ngan Kee Ng, then a graduate student at the National University of Singapore, examined the systematics of Ptychognathus barbatus, concluding that the populations described under this name represented two, rather than a single, species. Ng went on the lead a highly successful research group, specialising in the study of Crabs, for many years, before passing away in 2022, but never formerly published her PhD thesis. This means that all taxonomic nomenclature presented in the thesis is considered unusable under the terms of the International Code of Zoological Nomenclature, even if specialists in the field believe it to be generally correct.

In a paper published in the journal ZooKeys on 27 June 2025, Jhih-Wei Hsu of the Department of Life Science at the National Chung Hsing University, Jose Christopher Mendoza, of the Lee Kong Chian Natural History Museum at the National University of Singapore, and Hsi-Te Shih, also of the Department of Life Science, and of the Global Change Biology Research Center at the National Chung Hsing University, build upon Ngan Kee Ng's work, to formally divide Ptychognathus barbatus into two, and describe a new species.

The new species is named Ptychognathus dajie, where 'dajie' means 'elder sister', a title often used for women in leadership roles in Chinese-speaking countries, in honour of Ngan Kee Ng. A genetic analysis of museum specimens suggests that this species is found in estuaries and tidally-influenced portions of rivers, in Malaysia, Japan, Taiwan, China, Philippines, Indonesia, and Thailand. Surprisingly, Ptychognathus dajie is not particularly closely-related to Ptychognathus barbatus, instead forming a sister species to Ptychognathus guijulugani, a species found on Negros and Mindanao islands in the Philippines, placing it close to the base of the Ptychognathus family tree.

A neighbor-joining tree for species of Ptychognathus, based on the COI gene. Probability values at the nodes represent support values. Only values greater than 50% are shown. Hsu et al. (2025).

Specimens of Ptychognathus dajie have almost square carapaces, slightly wider than they are long, with a glossy upper surface and a concave frontal margin. The lower part of the claw is covered by long, thin setae; claws are larger in males than in females. The largest male specimen found was 20.2 mm wide and 16.8 mm long, the largest female found was 16.8 mm wide and 14.5 mm long. Colour is extremeley variable, and tends to match the substrate upon which the Crabs live.

Ptychognathus dajie. (A), (B) Holotype male (13.2 × 11.6 mm, ZRC 2024.0072); (C), (D) Paratype female (10.6 × 9.2 mm, NCHUZOOL 17356); (E) Male (NCHUZOOL 17341); (F) Male (NCHUZOOL 17343); (G), (H) Males (NCHUZOOL 7342). (A), (C) Dorsal view; (B), (D) Ventral view; (A)–(D) Preserved specimens; (E)–(H) Colour in life. Hsu et al. (2025).

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Coesite in Australasian microtektites.

Tektites and microtektites (i.e. very small tektites) are pieces of glass formed as ejecta from impact events. They are found in strewn fields which may extend thousands of kilometres from the original impact site. Current models of their formation suggest that they form from the material being impacted, as a spray of droplets of material melted by the rapid heating of the impact of an asteroid or comet fragment at speeds of over 3 km per second. However, while we have a general picture of how these events unfold, much of the detail is unclear. For example, many tektites from the Australasian Strewn Field contain inclusions of material, which have for a long time been accepted as fragments of the original rock trapped within a matrix of glass melt. This view has recently been challenged by an alternative hypothesis, that the matrix material may be a condensate from rock which was vapourised during the impact, and that the most distant microtektites, from Antarctica, may have formed from material which was vapourised by heat from the atmospheric shock wave before the impacting object touched down. This would help to explain why the Antarctic tektites lack inclusions, whereas in those from close to the presumed impact site, in Southeast Asia, they may make up as much as 5% of the mass of the tektite.

In a paper published in the journal Geology on 3 June 2025, Luigi Folco, Enrico Mugnaioli, and Matteo Masotta of the Dipartimento di Scienze della Terra and the Centro per la Integrazione della Strumentazione  at the Università di Pisa, and Billy Glass of the Department of Geosciences at the University of Delaware, present the results of a study of four microtektites from the Australasian Strewn Field.

The Australasian Strewn Field covers about 15% of the Earth's surface, and formed about 800 000 years ago through the hypervelocity impact of a chondritic body. It is the youngest and largest of five known Cainozoic strewn fields, with the others  being the North American Strewn Field, which is about 34.86 million years old (Eocene), the Central European Strewn Field, which is about 14.7 million years old (Miocene), the Côte d'Ivoire Strewn Field, which is 1.07 million years old (Pleistocene), and the Central American Strewn Field, which is about 820 000 years old (Pleistocene). No crater has been found which can be linked to the Australasian Strewn Field, although high pressure phases have been found in tektites and other ejecta which strongly indicate that the formation of the field was linked to a crater-forming event, probably in Southeast Asia or the surrounding seas, or possibly in northwest China.

Several previous studies have established that Australasian microtektites show Australasian microtektites with distance from the presumed impact site. For this reason Folco et al. selected three microtektites from deep-sea locations close to the putative impact site, SO95-17957-2,04 and ODP 1144A,01 from the South China Sea, and ODP 769A,15_26 from the Sulu Sea, and one, FRO 2.9-1, from a site in the Transantarctic Mountains. These samples were analysed using a combination of optical microscopy, microanalytical scanning electron microscopy, dual beam microscopy, and microanalytical transmission electron microscopy coupled with three-dimensional electron diffraction.

The Australasian Strewn Field microtektites from deep-sea settings are spheroid in shape and dark brown in colour, with a transluscent laustre and numerous inclusions. They range from 350 to 700 µm in maximum elongation, and dominated by silica phases, compositional bands (schlieren), and vesicles. SO95-17957-2,04 and ODP 1144A,01 have normal composition, whereas ODP 769A,15_26 has a high nickel content (232 µg/g). The Antarctic specimen is a pale-yellow transparent sphere 485 µm in diameter with normal composition,  devoid of vesicles, with only one microscopic silica-rich inclusion,  a few tens of micrometres across with diffuse boundaries. This is considered to be fairly typical of Australasian microtektites from Antarctica, although it is the only Antarctic Tektite known with a silica-rich inclusion.

Micrographs of sectioned Australasian microtektite SO95-17957-2,04. (A) Microtektite is pale brown with teardrop shape. It shows folded schlieren (Sch), microscopic vesicles (V), and mineral inclusions (arrowed). Thick white arrow points to inclusion studied in this work. Optical microscope image, plane polarized light. (B) Same petrographic features as in A in backscattered electron (BSE) image. White rectangle outlines field of view of image in panel C. (C) Close-up BSE image of a quartz (Qtz) + lechatelierite (L) + coesite (Coe) inclusion. Silica phases in the inclusion can be distinguished by their different electron density contrast, which increases from lechatelierite to quartz to coesite. A diffusive boundary layer (Dbl) discontinuously surrounds the inclusion. Dashed line traces location of the dual beam microscopy section. Folco et al. (2025).

Examined under the scanning electron microscope, the microtectites from deep-sea environments were found to contain a inclusions which comprise a matrix of vesiculated lechatelierite (shock-fused quartz glass), with variable proportions of microscopic quartz grains and submicroscopic coesite grains (coesite is a form of silica dioxide which only forms at very high pressures). These inclusions are surrounded by diffusive boundary layers a few microns thick. The quartz grains tend to be arranged around the edge of the inclusions, and themselves be surrounded by grains of coesite, while the interior of the inclusions tends to be dominated by lechatelierite. The quartz grains tend to be anhedral and heavily fractured, while the coesite grains comprise  polycrystalline aggregates of nanoscopic crystals set in silica glass. Towards the interior of the inclusions, the coesite grains become smaller, and comprise a higher proportion of silica-glass. The interior part of the inclusions, while dominated by vesiculated lechatelierite, contain many of these low-coesite 'coesite grains'. All three of these microtektites have essentially the same structure, although ODP 769A,15_26 and ODP 1144A,01 are more vesiculated than SO95-17957-2,04.

The Austrolasian microtektite ODP 769A,15_26. (A) Optical microscope, plain polarised image of the sectioned spherule, showing dark brown colour, prolate shape, schlieren, microscopic vesicles and transparent to partly opaque mineral inclusions. (B) The same textural and compositional features seen under scanning electron microscope, back scattered electron imaging mode. The white rectangle outlines the area of the next panel. (C) Back scattered electron view of a quartz + lechatelierite + coesite inclusion. Silica phases in the inclusion can be distinguished by their different contrast, which increases from lechaterlierite to quartz to coesite. The dashed line marks the position of the dual beam film featured in the next panel. (D) Transmission electron microscope image of a dual beam section showing tens of submicroscopic anhedral coesite grains dispensed in vesiculated lechatelierite. Inset: a close-up view of one coesite grain showing characteristic (010) polysnthetic twinning. The dashed line in panel (C) traces the location of the DB section seen in panel (D). Abbreviations: sch, schlieren; V, vesicle: Qtz, quartz; Coe, coesite; L,  lachatelierite. Thin white arrows indicate inclusions; the thick white arrow indicates the coesite bearing inclusion studied in detail. Folca et al. (2025). 

At the edge of the inclusion in microtektite SO95-17957-2,04 studied with dual beam microscopy, coesite could be seen forming euhedral crystals which overgrow the quartz grains. Towards the lechatelierite core of the inclusion, the coesite can be seen to be segmented in submicroscopict abular grains by a fine network of silica glass veinlets producing the polycrystalline aggregates. These coesite grains show a tartan-like texture similar to that seen in microcrystalline coesite aggregates in silica glass found in shocked porous sandstones. The proportion of silica glass between the segments of coesite within the grains increases towards the core of the inclusion, where anhedral nanoscopic grains of coesite can be found floating free within the lechatelierite core. 

Transmission electron microscopy images of electron transparent dual beam microscopy section of quartz + lechatelierite + coesite inclusions from Australasian deep-sea sediment microtektites. (A) Whole section of coesite-bearing inclusion in microtektite SO95-17957-2,04. White rectangle outlines area featured in panel (B). (B) Textural relationships between quartz (Qtz), coesite (Coe), and lechatelierite (L). Few microscopic quartz relicts at periphery of inclusion are overgrown by euhedral coesite grains with polysynthetic (010) twinning. Toward the core of the inclusion dominated by lechatelierite, coesite is segmented by a network of silica glass veinlets producing polycrystalline aggregates, which then disaggregate with increasing amount of silica glass. White rectangle traces area featured panel (C). (C) Close-up view of euhedral coesite (top) adjacent to polycrystalline aggregate with subhedral outline (bottom). (D) Reconstruction of reciprocal space sampled by three-dimensional electron diffraction from a twinned coesite grain. This picture displays a view of the diffraction volume along hh0 vector. Projections of 00l* and hh0* vectors are indicated. (E) Nanoscopic anhedral coesite grain with embayed crystal boundaries embedded in lechatelierite in microtektite ODP 769A,15_26. (F) Several nanoscopic anhedral coesite grains dispersed in an area of about 2 µm² of lechatelierite in microtektite ODP 1144A,01. Broken-apart grains are arrowed. Vesicle (V). Folco et al. (2025).

Inclusions in the Transantarctic Mountains tektite, FRO 2.9-1, could be seen to be featureless glass undr the scanning electron microscope, with diffuse contact with the glass matrix of the tektite. This host matrix was composed largely of silica, with smaller amounts of aluminium oxide, iron oxide, magnesium oxide, titanium oxide, calcium oxide, potassium oxide, and sodium oxide. The transmission electron microscope confirmed that this composition did not vary through the tektite.

The Australasian microtektite ODP1144A,01. (A) Optical microscope, plane polarized image of the sectioned particle. It is a brown glass broken tear drop. Few microscopic vesicles, and faint schlieren and few mineral inclusions are visible. (B) The same textural and compositional features seen under the scanning electron microscope, back scattered electron imaging mode. The white rectangle outline the area of the next panel. (C) Back scattered electron close-up view of a highly vesiculated quartz + lechatelierite + coesite inclusion. Silica phases in the inclusion can be distinguished by their different contrast, which increases from lechatelierite, to quartz to coesite. The dashed line marks the location of the dual beam film featured in the next panel. (D) Transmission electron microscope image of a dual beam section showing a polycrystalline aggregate of submicroscopіс anhedral coesite grains set in lechatelierite. The dashed line in panel (C) traces the location of the dual beam featured in panel (D). Abbreviations: Sch, schlieren; V, vesicle; Qtz, quartz; Coe, coesite; L, lechatelierite. Thin white arrows indicate inclusions; The thick white arrow indicates the coesite bearing inclusion studied in detail in this work. Folco et al. (2025).

Coesite is a fairly common mineral in settings where quartz-bearing rocks have been subjected to shock metamorphism. Whether it occurs as a metastable phase in shocked rocks that have experienced peak pressures and temperatures much beyond its stability field (i.e. pressures in excess of 10 gigapascals and temperatures in excess of 2700°C) has been debated since the 1960s. There are three current models of coesite formation. The first suggests that coesite may form in a silica melt as pressure decreases rapidly following an impact event. The second model suggests that coesite forms within silica glass at very high pressures, without any melting actually occurring. The third model also sees coesite forming within solid quartz, although this time in porous sandstones as the peak of the pressure wave passes through. 

In the Australasian microtektites, coesite appears to be overgrowing quartz crystals, which Folco et al. interpret as a sign that they formed while the matrix was under high pressure, but still in a solid state. However, the adjacent polycrystalline aggregates consisting of submicroscopic elongated grains of coesite pervaded by silica glass veinlets do indicate that some melting has occurred, possibly of the coesite itself, and the nanoscopic anhedral coesite grains dispersed in the surrounding lechatelierite as evidence to significant melting and dispersal of coesite aggregates. In this scenario the coesite nanocrystals re relicts formed by the melting and dispersal of larger, pre-existing coesite crystals during the shock-metamorphism process.

The presence of coesite in the Australasian microtektites provides information about the location of the putative Southeast Asian impact site. Coesite forms at very high temperatures, but is unstable unless cooled rapidly; it has been estimated that after 10 seconds at very high temperatures then all coesite will have transformed into cristobalite. Since there is no cristobalite in the Australasian microtektites, it can be inferred that quenching was much more rapid in this instance, possibly aided by reactions such as the transformation of quartz and coesite melt into lechatelierite, which is endothermic (absorbs heat).

The abundant quartz and lechatelierite inclusions found in Australasian tektites are generally accepted to be indicative of a quartz-bearing target rock which underwent melting and fusion during the impact event. The boundary between these inclusions and the glass matrix of the microtektites shows varying levels of diffuseness, suggesting that these particles underwent varying levels of digestion into the matrix. The presence of coesite in tektites from deep-sea environments off Southeast Asia supports the idea that these tektites are from close to the impact site, and represent melt spherules formed by compression and depression of the impacted rock during crater formation. The absence of coesite from the Transantarctic Mountains tektite, FRO 2.9-1, could imply that this remained at higher temperatures for longer, allowing all coesite to be reabsorbed, possibly implying this tektite was exposed not just the heat from the origianal impact, but also from deceleration in ambient air or atmospheric re-entry. This would explain the near-total absence of inclusions in these tektites, and also the homogenous distribution of elements and isotopes observed. There is no structure in the microtektite indicative exposure of high pressure, which supports the idea that these more distant microtektites formed by rapid heating of the target rock prior to the actual impact.

The presence of pressure-related minerals and structures in microtektites from the South China and Sulu seas strengthens the argument for a Southeast Asian impact event.

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