Mystery 'extinct' space rock found in Sweden

A morsel of never-before-seen alien rock has been dug up in a limestone quarry in Sweden, where it had lain deeply buried for about 470 million years, scientists have said.

The biscuit-sized remains are unlike any other meteorite found on Earth to date, and may shed light on the history and formation of our Solar System, they reported in the journal Nature Communications.

Dubbed Öst 65, it is thought to be a splinter of a potato-shaped rock some 20-30 kilometres (12-19 miles) wide, which had smashed into another much larger body, sprinkling our adolescent planet with debris.

Previously, remnants of only one of the two rocks had been found, in the form of meteorites called chondrites.

But now scientists believe they have unearthed a piece of the second space orb, boosting the theory of a major smash-up between two galactic travellers.

It is thought that the breakup of the bigger chondrite body, about 100-150km across, had yielded a major cluster of rocky debris in the asteroid belt between Mars and Jupiter.

The resultant flux of extraterrestrial material, some of which rained down on Earth, coincided with a massive expansion of invertebrate ocean life at a time our planet's landmass was largely fused together into a supercontinent called Gondwana.

"The single meteorite that we now found... is of a type that we do not know of from today's world," study co-author Birger Schmitz of Lund University in Sweden told AFP.

Along with about 100 chondrite pieces discovered to date, the new alien fragment had sunk to the floor of an ocean covering parts of what today is a limestone quarry in southern Sweden.

'Extinct' space rock? 

"The object contains very high concentrations (compared to Earth materials), of elements such as iridium, which is very rare on Earth," Schmitz explained by email.

"The meteorite also contains high concentrations of rare isotopes of the element Neon" -- and in different proportions than in chondrites.

The team measured telltale signs of cosmic radiation in the meteorite to determine how long it had flown around in space before crashing to Earth.

"Our meteorite fell 470 million years ago," said Schmitz -- more or less the same period as the chondrite fragments.

The mysterious morsel "may be a fragment of the impactor that broke up the (chondrite) parent body," concluded the study.

The extraterrestrial lander may be the first documented example of an "extinct meteorite" -- so called because it's parent body had been entirely consumed by space collisions, meaning no more fragments can fall to Earth today.

Chondrites still drop to our planet every now and then.

The findings mean that today's meteorites -- on which scientists base much of their assumptions about our Solar System's formation -- are not fully representative of what is, and once was, out there.

"Apparently, there is potential to reconstruct important aspects of solar-system history by looking down on Earth sediments, in addition to looking up at the skies," wrote the study authors.

Taken from The Local

Black Hole

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing - including particles and electromagnetic radiation such as light - can escape from inside it. The theory of general relativity predicts that a sufficiently compact mass to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although crossing the event horizon has enormous effect on the fate of the object crossing it, it appears to have no locality detectable features. In many ways  a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking Radiation, with the same kelvin for black holes of stellar mass, making it essentially impossible to observe. 

Objects whose gravitational fields are too strong for light escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was during the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.

Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. by absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may form. There is general consensus that supermassive black holes exist in the centers of most galaxies.

Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by friction, forming some of the brightest objects in the universe. If there are other stars orbiting a black hole, their orbits can be used to determine the the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary system, and established that the ration source known as Sagittarius A*, at the core of our own Milky way galaxy, contains a supermassive black hole of about 4.3 million solar masses.

Source: Wikipedia