Asteroid 2020 DA1 passes the Earth.

Asteroid 2020 DA1 passed by the Earth at a distance of about 193 600 km (0.50 times the average  distance between the Earth and the Moon, or 0.13% of the distance between the Earth and the Sun), slightly after 10.30 am GMT on Tuesday 18 February 2020. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2020 DA1 has an estimated equivalent diameter of 2-7 m (i.e. it is estimated that a spherical object with the same volume would be 2-7 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere more than 36 km above the ground, with only fragmentary material reaching the Earth's  surface.

 

The calculated orbit of 2020 DA1. JPL Small Body Database.

2020 DA1 was discovered on 17 February 2020 (the day before its closest encounter with the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2020 DA1 implies that the asteroid was the 25th object (asteroid A - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 24, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc) discovered in the Second half of February 2020 (period 2020 D).

2020 DA1 has a 455 day orbital period and an eccentric orbit tilted at an angle of 7.89° to the plane of the Solar System, which takes it from 0.49 AU from the Sun (i.e. 49% of he average distance at which the Earth orbits the Sun, slightly outside the orbit of the planet Mercury) to 1.81 AU from the Sun (i.e. 181% of the average distance at which the Earth orbits the Sun, and considerably outside the orbit of the planet Mars). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between the asteroid and Earth occasionally occur, with the last having occurred in October 2012, and the next predicted for August 2021. 2020 DA1 also has occasional close encounters with the planet Venus, with the last having happened in June 1926 and the next predicted for September 2027.

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Geologist shot dead in Bougainville, Papua New Guinea.

A geologist has been killed by an unknown assailant in the Bougainville Autonomous Region of Papua New Guinea. Channon Lumpoo, 27, a Thai National, was killed by a single shot from a high-powered riffle while installing equipment in the Kokoda area. He was working for Austhai Geophysical Consultants of Bangkok, who are carrying out surveying work in the area on behalf of the Philippine company SRMI.

The location of Bougainville Island, Papua New Guinea. Google Maps.

This is the second killing of a geologist in the area within a few months, following the death of Papuan National Terry Win Kilya in December 2019, who was apparently thrown from a cliff while carrying out surveying work for Kalia/Toremana Joint Venture Limited.

Bougainville Island voted for independence from Papua New Guinea in a referendum in December 2019. The island's relationship with the rest of the nation has long been problematic, with a civil war being waged by separatists in the 1990s. One of the major disagreements that have fuelled tensions has been the awarding of mining rights to foreign companies on the island by the Papuan government, which are perceived as brining little benefit to local people, while stripping the island of its natural wealth and damaging the environment.

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Homes evacuated after landslide in the Shandon District of Cork, Ireland.

Several homes were evacuated following a landslide on Eason's Hill in the Shandon District on the north-side of the City of Cork in Ireland on Thursday 20 February 2020. The landslip caused gardens behind the properties to vanish, and while the residents of the properties have now been allowed to return to them, they are now extremely concerned about the future safety of living in the area. The incident happened amid heavy rainfall associated with Storm Denis. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. 

 Properties undermined by a landslide on Eason's Hill in the Shandon District of Cork, Ireland, on Thursday 20 February 2020. Irish Examiner.

Residents of the area have asked the local council for help protecting their properties, however this request has been rejected so far on the basis that the landslip was triggered by the failure of a retaining wall (a structure designed to restrain soil to a slope that it would not naturally keep to), which was itself located on private land, making the issue one that should be settled between the landowners involved.

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Comet C/2019 K1 (ATLAS) makes its closest approach to the Earth.

Comet  C/2019 K1 (ATLAS) makes its closest approach to the Earth today (Monday 24 February 2020), reaching a distance of 2.29 AU from the Earth (229% of the distance between the Earth and the Sun, or 342 213 500 km). At this distance the comet will be not naked eye visible, having a magnitude of slightly over 16.3, (roughly the same as Pluto's moon Charon), in the Constellation of Hydra, which is better observed from the Southern Hemisphere.

 

The orbital trajectory and current position of C/2019 K1 (ATLAS).  The Sky Live 3D Solar System Simulator.

 

C/2019 K1 (ATLAS) was discovered on 16 May 2019 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) search program. The name C/2019 K1 (ATLAS) implies that it is a non-periodic comet (C/), that it was the third comet (comet 1) discovered in the second half of May 2019 (period 2019 K) and that it was discovered by the ATLAS program.

 

C/2019 K1 (ATLAS) is a Parabolic Comet, which is to say a comet that has been disrupted from an orbit in the Oort Cloud, and to be passing through the Inner Solar System on a parabolic orbit that will probably not bring it back again. This parabolic trajectory tilted at an angle of 87.2° to the plain of the Solar System, that brought it in to 2.01 AU from the Sun at perihelion (i.e. 2.01 times as far from the Sun as the planet Earth, or more than twice as far from the Sun as the planet Mars) on 12 February 2020.

 

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Brachyelatus marthae: A new species of Chrysolampine Wasp from Eocene Baltic Amber.

The highly diverse and economically important parasitoid Wasp superfamily Chalcidoidea is well known with approximately 20 000 extant species on six continents, but relatively few fossil species are known. However, a broad range of Chalcidoid fossils from the Eocene have been described. Two of these fossils, Perilampus pisticus and Palaeocharis rex represent the biologically derived Planidial group. This unique group of parasitoids is characterized by mobile and well sclerotized (thick skinned), but legless, first instar ‘planidial’ larva, which emerges from an egg laid some distance from the host instead of on or in the host. Later instars are of the sac-like type that is typical for Chalcidoidea.

In a paper published in the journal Insect Systematics and Diversity on 13 December 2019, Roger Burks of the Department of Entomology at the University of California, Riverside, Lars Krogmann of the Staatliches Museum für Naturkunde and the Institute of Zoology at the University of Hohenheim, and John Heraty, also of the Department of Entomology at the University of California, Riverside,describe a new species of Planidial Chrysolampine Wasp from Eocene Baltic Amber.

Baltic amber is the preserved resin of Eocene Coniferous Trees that formed huge forests covering much of Scandinavia and Northern Europe between about 56 and 34 million years ago. Since this amber floats, it is often found on beaches around the Baltic Sea, and sometimes further afield, making the precise dating of individual pieces difficult, though most Baltic Amber is thought to be about 46 million years old.

The new species is placed in the extant genus Brachyelatus, and given the specific name marthae, in honour of Roger Burks' mother, Martha. The species is described on the basis of five specimens, four females ranging from 1.3 to 1.9 mm in length and a male measuring 1.3 mm, and is assigned to the genus Brachyelatus on the basis of the pattern of veins in the wings (commonly used as a way to differentiate Insect species).

 Brachyelatus marthae. (1)–(5) Females, (1) Habitus (SMNS BB-2843). (2) Body in dorsal view (SMNS BB-2842). (3) Body in lateral view (SMNS BB-2844). (4) Body in ventral view (SMNS BB-2842). (5) Forewing venation (SMNS BB-2842); cs, uncal sensilla. (6) Male, head, anterior view (SMNS BB-2846); atp, anterior tentorial pit; Fu1, first funicular (second flagellomere); vp, ventral pores of scape. Burks et al. (2019).

The reproductive biology of modern Planidial Wasps is best known from studies of the genus Chrysolampus, which lays stalked eggs into seed pods within flower heads, which produce weakly sclerotized larvae search for their weevil host within the seed pods. Members of the genus Austrotoxeuma are potentially associated with Beetles in dead twigs, but otherwise, there is no other biological information for the subfamily. The genus Brachyelatus is known from three described and one undescribed species known from Europe, Transcaucasia, Australia, and Turkey, so the discovery of a species in Eocene Baltic Amber does not expand it's geographical range, but does increase the known temporal range of the genus and subfamily by an estimated 36 million years.

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Flights to and from the Canary Islands cancelled due to dust storm.

Flights to and from the Canary Islands have been cancelled today due to a major dust storm brought clouds of red sand from the Sahara to the islands, greatly reducing visibility. Several local events have also been cancelled due to the storm, and people with respiratory problems are being warned not to go outside until the storm has passed. The dust storm has been caused by winds of up to 120 km per hour over parts of North Africa, and is expected to pass on Monday 24 February 2020.

A dust storm in Santa Cruz de Tenerife on Sunday 23 February 2020. Andres Gutierrez/AP.

The predominant weather system over North Africa is the Saharan Air Layer, a hot, dry, and often dust-laden air system that prevents moister air from the Atlantic and Mediterranean brining rain to the area. Over the Atlantic this layer is typically forced up, above the moist, but cooler, sea air, carrying dust westward to South America. However, on some occassions a climatic inversion, whereby the air from the Saharan Air Layer is unable to move westward, and piles up in position till its upper layers become cool and dense enough to be forced down, brining a dense, dust-laden storm to the Canaries, known as a Calima.

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Asteroid 2020 CG2 passes the Earth.

Asteroid 2020 CG2 passed by the Earth at a distance of about 863 600 km (2.25 times the average  distance between the Earth and the Moon, or 0.58% of the distance between the Earth and the Sun), slightly before 8.20 am GMT on Monday 17 February 2020. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2020 CG2 has an estimated equivalent diameter of 25-78 m (i.e. it is estimated that a spherical object with the same volume would be 25-78 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 24 and 3 km above the ground, with only fragmentary material reaching the Earth's surface.

 240 second image of 2020 CG2 taken with the Elena Planetwave 17" Telescope at Ceccano in Italy on 16 February 2020. The asteroid is the small point at the centre of the image, the longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. Gianluca Masi/Virtual Telescope.

2020 CG2 was discovered on 14 February 2020 (three days before its closest approach to the Earth) by the Zwicky Transient Facility at Palomar Observatory in California. The designation 2020 CG2implies that it was the 55th asteroid (asteroid G2 - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 24, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc., which means that G2 = 7 + (24 X 2) = 55) discovered in the first half of February 2020 (period 2020 C).

The calculated orbit of 2020 CG2. JPL Small Body Database.

2020 CG2 has a 892 day (2.44 year) orbital period and an eccentric orbit tilted at an angle of 8.11° to the plane of the Solar System, which takes it from 0.97 AU from the Sun (i.e. 97% of he average distance at which the Earth orbits the Sun) to 2.66 AU from the Sun (i.e. 266% of the average distance at which the Earth orbits the Sun, and considerably outside the orbit of the planet Mars). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between the asteroid and Earth occasionally occur, with the last having occurred in January 2008, and the next predicted for May 2027.

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