Scientists record Planet Nine, eighth continent, Zealandia, breakthroughs
Scientists have made two major breakthroughs with the discovery that two faraway objects may once have made up a binary asteroid in Earth’s solar system before being separated and pushed into their current orbits by the mysterious Planet Nine millions of years ago.
Also, geologists have found that beneath the waves in the southwest Pacific Ocean lays a mostly hidden realm — dubbed Zealandia — that deserves to be called a continent.
Astronomers concluded in a new study first published in DailyMailUK Online, which conducted the first spectroscopic observations of asteroids 2004 VN112 and 2013 RF98 – a pair with nearly identical orbits- that these asteroids may have a common origin, and suggests they were influenced by an encounter with a much more massive object, adding support to the existence of the hypothetical planet on the edge of our solar system.
Using the OSIRIS spectrograph on the Gran Telescopio CANARIAS (GTC), in the Roque de los Muchachos Observatory, the researchers found that the objects’ orbits are almost identical, and the poles are separated by just a small angle.
The team also analyzed the visible spectrum to determine their composition, including whether they have pure ice on the surface, highly processed carbon compounds, or even the possible presence of amorphous silicates.
The values for 2004 VN112 and 2013 RF98 suggest they had a common origin. According to the researchers, a larger object, possibly Planet Nine, may have altered the orbits of these two objects.
Numerical simulations showed that a possible planet with a mass between 10 and 20 Earth masses orbiting the Sun at a distance of 300-600 AU could have caused the split around five and 10 million years ago.
In the study, researchers led by the Astrofísica de Canarias (IAC) and Complutense University of Madrid examined distant objects known as ETNOs: the ‘extreme trans Neptunian objects.’
These orbit the Sun at a distance greater than that of Neptune, and to date, a total of 21 have been identified. Still, much about these objects remains a mystery.
Meanwhile, geophysical data suggest that a region spanning five million square kilometres, which includes New Zealand and New Caledonia, is a single, intact piece of continental crust and is geologically separate from Australia, a team of scientists from New Zealand, Australia and New Caledonia argue in the March/April issue of GSA Today.
“If you could pull the plug on the world’s oceans, then Zealandia would probably long ago have been recognized as a continent,” says team leader Nick Mortimer, a geologist at GNS Science in Dunedin, New Zealand.
However, there is no international body in charge of designating official continents, and so the researchers must hope that enough of their colleagues agree to recognize the landmass. Otherwise, their proposal could remain more of a theoretical wish than a radical reshaping of what every child has to learn in geography class.
“The results are pushing us to rethink how broadly we can or should apply the established definition of geological continental landmasses,” says Patricia Durance, a mineral geologist at the GNS Science office in Lower Hutt, New Zealand.
Mortimer and his colleagues have been making the case for Zealandia for more than a decade, in talks, popular articles and books; the latest paper is their most technical synthesis yet. In it, they report that Zealandia began to peel away from the supercontinent of Gondwana starting about 100 million years ago.
The rift gave Zealandia its independence, but it also pulled and thinned the crust, causing the area to sink, and dooming most of it to a watery existence. Today, only about six per cent of it remains above water, as New Zealand and New Caledonia.
Satellite maps made using Earth’s gravitational field clearly show that Zealandia is a coherent geographical feature stretching from near Australia’s northeastern coast well past the islands of New Zealand, Mortimer says. Sea-floor samples reveal that Zealandia consists of light continental crust and not the dark volcanic rocks that make up nearby underwater plateaus. The area seems to be structurally intact, rather than a mash-up of different continental-crust fragments.