Water covers three-quarters of the Earth’s surface and was crucial for the emergence of life, but its origins have remained a subject of active debate among scientists.
Now, a 4.6 billion-year-old rock that crashed on to a driveway in Gloucestershire, UK last year has provided some of the most compelling evidence to date that water arrived on Earth from asteroids in the outer solar system.
The Winchcombe meteorite, one of the “most pristine” available for analysis, offered scientists “a tantalizing glimpse back through time to the original composition of the solar system 4.6 billion years-ago,” said Ashley King, a research fellow at the Natural History Museum in London and author of a new paper on the space rock.
Photo: EPA-EFE
A prevailing theory is that the Earth was barren when it formed, as the inner region of the solar system was too hot for water to condense. The boundary of the region where ice could form in the early solar system is known as the frost line, and is located in the modern asteroid belt. Scientists think that water could have arrived to Earth later, raining down in icy meteoroids and large impacts.
However, there are competing theories, including that water was brought on comets — made mostly of ice and dust — or other similar bodies.
The latest analysis adds weight to the theory that asteroids made a leading contribution to water on Earth. Most of the Winchcombe meteorite was recovered just hours after its spectacular fireball lit up the skies over the UK in February last year during lockdown. One of the largest pieces was discovered on the driveway of the Wilcock family home, and a few smaller pieces were found in nearby gardens.
It is the first-ever carbonaceous chondrite meteorite — the oldest class of meteorites, which contain materials present during the formation of the solar system — to have been found in the UK. Crucially, it was collected within hours of being detected, before any rainfall, and analyzed almost immediately, making it a rare uncontaminated specimen.
The incoming meteorite was also recorded by 16 dedicated meteor cameras, and numerous doorbell and dashcam videos, meaning that scientists could produce an accurate trajectory of where it came from in the solar system. By contrast, most of the 70,000 known meteorites have been found without their impact being recorded — in some cases millions of years after they landed.
“They’re just random rocks that have come to us from space,” King said.
The analysis, published in the journal Science Advances, concludes that the meteorite originated from an asteroid body somewhere near Jupiter. The research also found that the ratio of hydrogen isotopes in the water closely resembled the composition of water on Earth.
“Meteorites like Winchcombe are a pretty good match [to] the water in the Earth’s oceans and suggests asteroids were the main source of water,” said King.
Extracts from the Winchcombe meteorite also contain extraterrestrial amino acids — prebiotic molecules that are fundamental building blocks for the origin of life.
As the composition of the Winchcombe meteorite is so pristinely preserved, the analysis suggests that similar asteroids have played a significant role in delivering the ingredients needed to kickstart oceans and life on early Earth.
That US assistance was a model for Taiwan’s spectacular development success was early recognized by policymakers and analysts. In a report to the US Congress for the fiscal year 1962, former President John F. Kennedy noted Taiwan’s “rapid economic growth,” was “producing a substantial net gain in living.” Kennedy had a stake in Taiwan’s achievements and the US’ official development assistance (ODA) in general: In September 1961, his entreaty to make the 1960s a “decade of development,” and an accompanying proposal for dedicated legislation to this end, had been formalized by congressional passage of the Foreign Assistance Act. Two
Despite the intense sunshine, we were hardly breaking a sweat as we cruised along the flat, dedicated bike lane, well protected from the heat by a canopy of trees. The electric assist on the bikes likely made a difference, too. Far removed from the bustle and noise of the Taichung traffic, we admired the serene rural scenery, making our way over rivers, alongside rice paddies and through pear orchards. Our route for the day covered two bike paths that connect in Fengyuan District (豐原) and are best done together. The Hou-Feng Bike Path (后豐鐵馬道) runs southward from Houli District (后里) while the
President William Lai’s (賴清德) March 13 national security speech marked a turning point. He signaled that the government was finally getting serious about a whole-of-society approach to defending the nation. The presidential office summarized his speech succinctly: “President Lai introduced 17 major strategies to respond to five major national security and united front threats Taiwan now faces: China’s threat to national sovereignty, its threats from infiltration and espionage activities targeting Taiwan’s military, its threats aimed at obscuring the national identity of the people of Taiwan, its threats from united front infiltration into Taiwanese society through cross-strait exchanges, and its threats from
March 31 to April 6 On May 13, 1950, National Taiwan University Hospital otolaryngologist Su You-peng (蘇友鵬) was summoned to the director’s office. He thought someone had complained about him practicing the violin at night, but when he entered the room, he knew something was terribly wrong. He saw several burly men who appeared to be government secret agents, and three other resident doctors: internist Hsu Chiang (許強), dermatologist Hu Pao-chen (胡寶珍) and ophthalmologist Hu Hsin-lin (胡鑫麟). They were handcuffed, herded onto two jeeps and taken to the Secrecy Bureau (保密局) for questioning. Su was still in his doctor’s robes at
RSS