Monday, 4 May 2026

The Eta Aquariid Meteor Shower.

The Eta Aquariid Meteor Shower will peak before dawn on Wednesday 6 May 2026, with up to 45 meteors per hour at it's peak, radiating from the constellation of Aquarius. The radiant point of this shower does not spend long above the horizon in the Northern Hemisphere at this time of year, but is often a good display in the Southern Hemisphere between midnight and dawn. The Eta Aquarids are potentially visible between 19 April and 28 May, but are extremely hard to spot away from the peak of activity. With the last Quarter Moon in Sagittarius, pre-dawn viewing may suffer from some light interference. 

The radiant point (point from which the meteors appear to radiate) of the Eta Aquariid Meteors. Universe Today.

Meteor showers are thought to be largely composed of material from the tails of comets. Comets are composed largely of ice (mostly water and carbon dioxide), and when they fall into the inner Solar System the outer layers of this boil away, forming a visible tail (which always points away from the Sun, not in the direction the comet is coming from, as our Earth-bound experience would lead us to expect). Particles of rock and dust from within the comet are freed by this melting (strictly sublimation) of the comet into the tail and continue to orbit in the same path as the comet, falling behind over time.

The Earth passing through a stream of comet dust, resulting in a meteor shower. Not to scale. Astro Bob.

The Eta Aquarid Meteor  Shower is caused by the Earth passing through the trail of Halley's Comet, where it encounters thousands of tiny dust particles shed from the comet as its icy surface is melted (strictly sublimated) by the heat of the Sun. Halley's Comet only visits the inner Solar System every 75 years (most recently in 1986 and next in 2061), but the trail of particles shed by it forms a constant flow, which the Earth crosses twice each year; in May when it causes the Eta Aquarid Meteor Shower and in October when it causes the Orionid Meteor Shower.

Halley's Comet imaged on 8 March 1986 from Easter Island. William Liller/International Halley Watch Large Scale Phenomena Network/NASA/Wikimedia Commons.

Halley's Comet has been observed repeatedly and recognised as the same recurring object since at least 240 BC. However, it takes its modern name from the eighteenth century English Astronomer Edmund Halley, who determined the comet's periodicity in 1705.

Halley's Comet completes one orbit every 75.32 years (27 509 days) on an eccentric, orbit tilted at 162° to the plane of the Solar System (i.e. a retrograde orbit, at an angle of18° to the plane of the Solar System, but travelling in the opposite direction to the majority of the objects in the Solar System), that takes it from 0.56 AU from the Sun (59% of the average distance at which the Earth orbits the Sun, and inside the orbit of the planet Venus) to 35.1 AU from the Sun (35.1 times as far from the Sun as the Earth, and outside the orbit of the planet Neptune). As a comet with a period of more than 20 years but less than 200 years, Halley's Comet is considered to be a Periodic Comet, and a Halley-type Commet.

The orbit of Halley's Comet. Nagual Design/Wikimedia Commons.

Halley's Comet was visited by the European Space Agency's Giotto Probe in and Russian Vega 1 and Vega 2 probes March 1986, which were able to determine that the nucleus of the comet was only 15 km across, although it was surrounded by a coma about 100 000 km in diameter, made up of fragments of dust and ice released from the surface as it was heated by the Sun, causing the ices on its surface to sublimate (turn directly from solids to gasses), and that this material comprised 80% water, 10% carbon monoxide, 2.5% methane and ammonia, as well as trace amounts of more complex hydrocarbons, iron and sodium.

Halley's Comet imaged by the Giotto Probe on 14 March 1986. European Space Agency/Wikimedia Commons.

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Friday, 24 April 2026

World Malaria Day.

World Malaria Day is marked on 25 April each year, with the aim of raising awareness of both the disease and efforts to combat it. The day was originally adopted as Africa Malaria Day in 2001, following the signing of the Abuja Declaration at the African Summit on Malaria in 2000. This was adopted as an international observance at the 60th session of the World Health Assembly in 2007.

On World Malaria Day in 2026 the World Health Organization will be launching the campaign 'Driven to End Malaria: Now We Can. Now We Must.', which marks the fact that for the first time ever, ending Human Malaria is a genuine possibility. This includes the development of vaccines for Malaria, which are now being rolled out in 25 countries, as well as the development of genetically modified Mosquitoes which cannot spread the disease, improved Mosquito nets which are infused with dual action insecticides, seasonal chemoprevention measures which are now being offered to 54 million children in countries where Malaria is endemic, a widening of access to perennial (year round) chemoprevention, and better treatments for patients with Malaria.

Official World Malaria Day 2026 logo. World Health Organization.

Malaria is caused by parasitic unicellular Eukaryotes of the genus Plasmodium, and affects a wide range of terrestrial Vertebrates. Five different species of Plasmodium can cause Malaria in Humans, with most infections caused by either Plasmodium falciparum or Plasmodium vivax. The parasites are primarily spread via the bite of the female Anopheles Mosquitoes (males do not bite), but can also be spread through blood transfusions, organ transplants, or practices such as needle-sharing.

Photomicrograph of a blood smear containing a macro- and microgametocyte of the Plasmodium falciparum parasite. Both macro- and microgametocytes are products of the erythrocytic life cycle. Within a few minutes after the Anopheles sp. vector ingests the gametocytes, microgametocytes develop into microgametes, which are able to fertilize gametes. Centers for Disease Control and Prevention/Wikipedia Commons.

Malaria manifests with approximately 10-15 days after infection, as a fever, headache, and chills. Mild cases often pass soon, and can be difficult to identify as Malaria, however, more severe cases can be fatal in as little as 24 hours after the onset of symptoms. 

To date, 47 countries have been declared Malaria-free, with another 46 countries reporting less than 100 000 cases of locally acquired Malaria in 2024 (the last year for which reliable figures are available). Of those 46 countries, 37 reported less than 1000 cases, 26 reported less than 100 cases, and 24 reported less than 10.

Nevertheless, the situation is not all progress; 610 000 people died as a result of Malaria in 2024, an increase on the 598 000 who died in 2023. Four countries (Eritrea, Rwanda, Tanzania, and Uganda) have reported the emergence of strains of Malaria resistant to Artemisinin, the main treatment for the disease. Furthermore, 48 countries have reported Mosquitoes developing resistance to pyrethroid insecticides, which are the most commonly used to treat Mosquito nets hung over beds. Many strains of Malaria have also emerged which lack the pfhrp2 gene, which is used in diagnostic kits, delaying treatment in many cases. The Mosquito Anopheles stephensi, which is endemic to India, has been spreading in Africa in recent years. This Mosquito caries Malaria, and is a preferential urban-dweller, placing many people at greater risk.

Another serious threat is a massive shortfall in funding for Malaria programs, with US$5.4 billion in funding (more than half the total) being cut in 2025, with the United States, the United Kingdom, Germany, France, and Japan all making significant cuts to their aid programs. This has served to underline the fragility of aid programs which are reliant on the good will of a small number of wealthy donor countries.

Malaria eradication programs have also stalled due to civil conflicts and natural disasters, with major flooding events, which often co-occur with Malaria outbreaks, becoming more common due to the warming climate.

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Wednesday, 22 April 2026

The Temple of the Mud God.

Archaeologists working at a site on the northeastern fringe of the Nile Delta have uncovered what they believe to be a temple to a god of mud, according to a press release issued by the Egyptian Ministry of Tourism and Antiquities on their Facebook page. The site, which lies within the ancient city of Pelusium (or Blozium), a name which itself means 'mud', was first identified in 2019, when a portion of a red brick circular structure was uncovered, something which was originally identified as a possible Senate building, dating from the cities Greek or Roman period.

A section of the red brick wall surrounding the temple complex at Pelusium. Egyptian Ministry of Tourism and Antiquities.

When fully uncovered the structure proved to be a huge circular basin 35 m in diameter, with a plinth in the middle for a statue. This was connected to a system of cisterns and channels which would have carried salty, silt-laden water from the Pelusic Nile (the 'Muddy' Nile, one of the branches of the Nile Delta) into the basin, which has been interpreted as a religious centre for the God Pelusius, or Blozius, whose name meant 'mud' and who was the patron deity for the city.

The exposed temple site. Egyptian Ministry of Tourism and Antiquities.

The site is thought to have been in use from the second century BC until the sixth century AD, i.e. through the Greek and Roman periods of the city, and is being compared to other temples in the Hellenic and Roman worlds rather than to other Egyptian temples.

Archaeologists working on the temple site. Egyptian Ministry of Tourism and Antiquities.

The city of Pelusium was established as a port at the eastern margin of the marshes of the Nile Delta during the Egyptian Old Kingdom, but this port had silted up by the first century BC. Today, the city is several kilometres from the sea, and lies in the northwest Sinai Desert, cut off from the Nile Delta by the Suez Canal. The city was a significant border fortress to the Egyptians, and remained an important administrative centre during Roman times. It was noted for the production of flax and beer.

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Dwarf Planet 136108 Haumea approaches opposition.

The Dwarf Planet 136108 Haumea will reach opposition (i.e. be directly opposite the Sun seen from Earth) at 8.47 am GMT on Thursday 23 April 2026. This means that it will both be at its closest to the Earth this year, about 42.1 AU (42.1 times the average distance between the Earth and the Sun, or about 6 298 255 000 km), and completely illuminated by the Sun. While it is not visible to the naked eye observer, the planets have phases just like those of the Moon; being further from the Sun than the Earth, 136108 Haumea is 'full' when directly opposite the Sun. 

The orbit and position of 136108 Haumea and the planets of the Solar System at 9.00 am on Thursday 23 April 2026. JPL Small Body Database Browser.

At opposition, the Dwarf Planet will be in the constellation of Bootes and at its highest point in the sky at about midnight local time from anywhere on Earth (this is because the rising and setting of objects in the sky is caused by the Earth's rotation, not the movement of the object). (Even at it's very brightest 136108 Haumea will only have a Magnitude of 17.3, making it almost impossible to see with any but the largest of Earth-based telescopes, and where resolvable it will only be possible to see it as a point of light indistinguishable from a faint star.

136108 Haumea orbits the Sun on an eccentric orbit tilted at an angle of 28.2° to the plane of the Solar System, which takes it from 34.4 AU from the Sun (34.4 times the average distance at which the Earth orbits the Sun) to 51.5 AU from the Sun (51.5 times the average distance at which the Earth orbits the Sun). With an average distance of 43.0 AU, 136108 Haumea completes one orbit around the Sun every 282 years. This means that the planet is almost stationary compared to the faster moving Earth, so that it reaches Opposition only one day later each year than the year before, and reaches Solar Conjunction (when it is directly on the opposite side of the Sun to the Earth), roughly six months later.

136108 Haumea was discovered on 28 December 2004 by a team led by Mike Brown of the Palomar Observatory in California, in images taken by them on 28 May 2004; on 27 July 2005 a team led by José Luis Ortiz Moreno and his team at the Instituto de Astrofísica de Andalucía reported that they had also discovered the Dwarf Planet, in images taken between 7 and 10 March 2003. With a diameter of 2100 km it is considered to be the third largest dwarf planet in the Solar System (after 134340 Pluto and 136199 Eris) as well as the eighteenth largest body in the Solar System, excluding the Sun (several moons, including our own, are larger).

Haumea has been calculated to be rotating once every 3.9 hours, far more rapidly than any other large body in the Solar System. Curiously for such a fast rotating body, it has not adopted a oblate spheroid (flattened sphere) shape, but is instead a triaxial ellipsoid (elongate flattened sphere, or flattened egg-shape). This implies that, although its surface is comprised of ice, it has a core of fairly dense rocky material. 

The Dwarf Planet Haumea is believed to rotate in just under 4 hours. This rapid rotation causes the Dwarf Planet to be elongated in appearance. Stephanie Hoover/Wikimedia Commons.

Although Haumea is only about a quarter the size of Pluto, it is thought to be large enough that it should have reached hydrostatic equilibrium (i.e. become approximately spherical due to its own gravity). The elongate shape of Haumea is at odds with this, something which, in combination with its high rotational rate, has been suggested as evidence of a major collision in Haumea's past. This has been supported by the discovery in 2017 of a ring surrounding the dwarf planet with a radius of about 2285 km. This is well within the Roche limit for Haumea (the distance below which a ring or other orbiting body should be disrupted by the parent body's gravity and either fall onto it or be ejected), suggesting that this is a temporary structure caused by a relatively recent event (although still potentially billions of years ago, given the weak gravitational forces involved).

136108 Haumea rotating within its ring system. Tom Ruen/Wikimedia Commons.

136108 has two small moons, both of which were discovered in 2005 by Darin Ragozzine and Michael Brown, at that time working at the W. M. Keck Observatory in Hawai'i. The larger of these, Hi'iaka, is roughly 370 km in diameter (although, like its parent body, it has been calculated to have an elongate, non-spherical shape) and orbits at a distance of 49 400 km, completing one orbit every 49.5 days. The smaller, Namaka, has been calculated to be about 150 km in diameter with an irregular shape, and to orbit at a distance of approximately 25 500 km.

Both the rings of 136108 Haumea and the larger moon, Hi'iaka, follow orbital paths 1-3° offset from the equator of the dwarf planet, and are thought to be products of the same collision. The smaller moon, Namaka, has an orbit offset by 69° from the equator of Haumea. This moon is thought to have been formed in the same collision, but to have had it's orbit perturbed significantly by tidal interactions with the larger moon.

Dwarf Planet Haumea and its satellites, imaged by the Hubble Space Telescope's WFC2 camera from 12 May 2008 and 19 May 2008. The brighter dot orbiting Haumea is the larger outer moon Hi'iaka while the fainter dot is the smaller inner moon Namaka. This animation of the moons' orbits spans 7 days and the orbital plane of Namaka is oriented vertically. Hubble Space Telescope/Michael Brown/Wikimedia Commons.

136108 Haumea is thought to be a member of a collisional family of Kuiper Belt objects; the only collisional family identified from this part of the Solar System. This family has been named the Haumea, or Haumean, Family in reference to its largest known member. Collisional families are groups of bodies which appear to have been created in a single collision event, and whose orbital trajectories can in theory all be traced back to a single point of origin, although this is not the case for the Haumea Family, which are thought to have had their orbital paths modified over time by interactions with the gravitational field of Neptune. 

As well as 136108 Haumea and its ring and moons, this family is thought to include the Kuiper Belt Objects (19308) 1996 TO66, (24835) 1995 SM55, (55636) 2002 TX300, (86047) 1999 OY3, (120178) 2003 OP32, (145453) 2005 RR43, (202421) 2005 UQ513, (308193) 2005 CB79, (315530) 2008 AP129, (386723) 2009 YE7, (416400) 2003 UZ117, (523645) 2010 VK201, (543454) 2014 HZ199, (612620) 2003 SQ317, (653589) 2014 QW441, (671467) 2014 LO28, and (673087) 2015 AJ281, as well, presumably, as other as yet undiscovered bodies.

The orbits of the bodies of the Haumea Collisional Family (not all are shown). Tom Ruen/Wikimedia Commons.

As well as having similar orbital properties, the bodies of the Haumea Family all share a similar high albedo (with the exception of (202421) 2005 UQ513), which suggests a surface largely covered by reflective water ice, rather than the darker, reddish, tholins (frozen organic compounds) which cover the surface of most Kuiper Belt objects. (202421) 2005 UQ513 has a lower albedo and a reddish spectrum, suggesting that it has an outer surface covered with tholins, but is included within the Haumea Family due to the similarity of its orbit.

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Tuesday, 21 April 2026

Stela depicting Roman Emperor Tiberius Caesar as Egyptian Pharaoh discovered at Karnak Temple.

Archaeologists from the Egyptian-French Center for the Study of the Temples of Karnak have uncovered a stela (stone tablet) depicting the Roman Emperor Tiberius Caesar as the Egyptian Pharaoh while working on a restoration project, according to a press release issued by the Egyptian Ministry of Tourism and Antiquities on their Facebook Page. The stela, which is approximately 60 cm high, 40 cm wide, and 10 cm deep, is made out of sandstone and depicts the Emperor dressed as a Pharaoh and making an offering to the Egyptian gods Amun-Ra, Mut, and Khonsu. 

A stela discovered at the Temple of Karnak in Luxor, depicting the Roman Emperor Tiberius Caesar dressed as Pharaoh of Egypt making offerings to the Egyptian gods Amun-Ra, Mut, and Khonsu. Egyptian Ministry of Tourism and Antiquities.

Amun-Ra, Mut, and Khonsu (known as the 'Thebian Triad') were a trinity of gods worshipped at Thebes, who became important throughout Egypt from the New Kingdom onwards. Amun-Ra was a fusion of the earlier gods, Amun, one of the eight deities the Old Kingdom held responsible for the creation of the universe, and the Sun God Ra. His consort, Mut (which translates as 'mother') was said to have given birth to the world, and everything in it. This originally appears to have been a separate creation myth, but over time she became associated with Amun-Ra, with the pair becoming a divine couple. The god Khonsu was seen as the son of this divine couple, and was also associated with the creation of the universe, as well as having responsibility for moving the Moon across the heavens. 

Paying tribute to this triad of gods was an important part of the duties of the Pharaoh, who was the head of the Egyptian religion as well as ruler of the country. The title of Pharaoh passed to the Roman Emperors when the state was brought into the Roman Empire by the first emperor, Augustus, in 27 BC, which meant such duties at least in theory passed to the Roman ruler. It is, however, unlikely that Tiberius (or any other emperor) travelled to Egypt to perform the role, it is likely that having a representative do this was acceptable to the Egyptians. Egypt had previously been part of the Achaemenid Empire, whose rulers were equally unlikely to travel to Egypt for local religious ceremonies, so it is likely that a procedure for this eventuality was available long before the Roman conquest.

On the Roman side, adopting local religions was a part of the strategy used in integrating new territories into their Empire, often by declaring that local gods were aspects of, or alternative names for, their own gods. This often involved investment in temples, shrines, and other religious infrastructure that local sects had not previously enjoyed, increasing the status of the local religion, and provided people travelling from the provinces with impressive temples to their own gods in Rome. In Egypt, the same approach had already been taken by the Ptolemaic Pharaohs, who had paired Egyptian gods with their Greek equivalents, providing a template for the Romans to follow. Thus Amun was seen as the equivalent of Jupiter, a respectable god for a Roman Emperor to be depicted worshipping.

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