Earth-like planet with atmosphere, discovered 26 light years away
Representational image of Earth
For the first time, scientists have discovered a rocky Earth-like exoplanet with a partially preserved atmosphere — giving researchers a chance to glimpse into an atmosphere of a planet outside our solar system.
While a wide variety of exoplanets, made of rock, ice and gas have been discovered in the last couple of decades, studying the atmosphere of rocky planets is extremely difficult with currently available instruments. For that reason, atmospheric models for rocky planets remain untested.
Researchers have now discovered a hot super-Earth in orbit around a nearby red dwarf star Gliese 486 — only 26 light years away from the Sun.
The planet, named Gliese 486b, has a mass 2.8 times that of the Earth, and is only 30 per cent bigger. It orbits its host star on a circular path every 1.5 days — at a distance of 2.5 million km.
In spite of being so near to its star, the planet has probably conserved part of its original atmosphere, thus becoming a good candidate to observe in more detail with the next generation of space and ground telescopes.
Gliese 486b takes the same length of time to spin on its axis as to orbit its host star, so that it always has the same side facing the star.
Although Gliese 486 is much fainter and cooler than the Sun, the radiation is so intense that the surface of the planet heats up to at least some 430 degrees Celisus. Because of this, the surface of Gliese 486b is probably more like the surface of Venus than that of the Earth — with a hot dry landscape and burning rivers of lava.
However, unlike Venus, Gliese 486b may have a thin atmosphere.
Researchers have for the first time found water and organic matter on the surface of an asteroid sample returned from the inner solar system. This marks the first time that organic materials — which could have provided chemical precursors for the origin of life on Earth — have been found on an asteroid.
During the Japanese space agency JAXA’s first Hayabusa mission in 2010, a single grain of sample was returned to Earth from asteroid Itokawa.
The sample shows that water and organic matter that originate from the asteroid itself have evolved chemically through time.
The research team suggests that Itokawa has been constantly evolving over billions of years by incorporating water and organic materials from foreign extra-terrestrial material, just like the Earth.
In the past, the asteroid would have gone through extreme heating, dehydration and shattering. However, despite this, the asteroid came back together from the shattered fragments and rehydrated itself with water that was delivered via dust or carbon-rich meteorites.
The single grain from the asteroid, nicknamed ‘Amazon’, has preserved both unheated and processed organic matter within ten microns of distance.
The organic matter that has been heated indicates that the asteroid had been heated to over 600 degrees Celsius in the past. The presence of unheated organic matter very close to it, means that primitive organics arrived on the surface of Itokawa after the asteroid had cooled down.
Scientists have revealed that Earth has an extra layer — an innermost inner core. Traditionally, we’ve been taught the Earth has four main layers — the crust, the mantle, the outer core and the inner core.
But this week, researchers from The Australian National University said that while this new layer is difficult to observe, its distinct properties may point to an unknown, dramatic event in the Earth’s history.
The team found evidence that may indicate a change in the structure of iron, which suggests two separate cooling events in Earth’s history.
Investigating the structure of the inner core can help us understand more about the Earth’s history and evolution.
The idea that this innermost inner layer exists was proposed a couple of decades ago, but the data has been very unclear until now.
