Life from Earth may already exist on alien planets (article)

Life from Earth may already exist on alien planets after being carried there by tiny specks of space dust

http://www.dailymail.co.uk/sciencetech/article-5103077/Alien-bugs-hitched-lift-Earth-SPACE-DUST.html

Space dust may have transported alien bugs to Earth and terrestrial microbes to other planets, research suggests.

The theory comes from scientists in Edinburgh who have studied powerful flows of interplanetary dust that can travel through space at up to 43.75 miles per second (70km/s).

They calculated that small bio-particles floating high in the atmosphere at an altitude of 93 miles (150 km) or more could be knocked free of the Earth’s gravity by incoming space dust.

Eventually the tiny organisms could reach other planets in the solar system.

Some bacteria, plants and even hardy micro-animals called tardigrades are known to be capable of surviving in space.

The same process could occur in reverse, bringing extraterrestrial bugs to Earth and possibly helping to seed life on the planet, the scientists believe.

Study leader Professor Arjun Berera, from the University of Edinburgh’s School of Physics and Astronomy, said: ‘The proposition that space dust collisions could propel organisms over enormous distances between planets raises some exciting prospects of how life and the atmospheres of planets originated.

‘The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life.’

In 2016, researchers from Esa have found a faint amount of interstellar dust appears in one of Saturn’s ice rings, made of material that came from its moon Enceladus.

The team examined a total of 36 interstellar dust grains, more than five times the number of previous direct detections.

The results found the grains were mainly made of magnesium, calcium, iron, silicon and oxygen.

Giovanni Cassini was the first astronomer to recognise this dust in interplanetary space, and its presence around the sun, through telescopic observations in the 17th century.

Previously scientists have considered the possibility of impacting asteroids and comets importing life, or the raw ingredients of life, to Earth.

Earlier this year, researchers from Columbia University said life may have travelled on an asteroid from Mars and come to Earth.

The radical theory, called Panspermia, was first proposed in 1871, and has since been gaining traction among the scientific community.

The Panspermia theory suggests that Mars once had the right conditions for life to form, including water and an atmosphere.

But an asteroid collision caused by rocks in the solar system hitting each other may have caused a chunk of life from Mars to land on Earth.

Astronomer and director of the multidisciplinary Columbia Astrobiology Centre at Columbia University, Caleb Scharf, told Business Insider: ‘We can find pieces of Mars here on Earth and we suspect that there are pieces of Earth on Mars.

‘If that material can carry living organisms on it, it’s possible that we are Martian.’

Panspermia is not a new thoery – it was first proposed in 1871 – but it has more recently gathered fresh support as astronomers have discovered just how full the universe is with organic compounds.

Although no evidence to prove this has yet been found, the idea of Panspermia, which remains on the fringe of mainstream science, is not considered as far-fetched as it once was.

The new research, published in the journal Astrobiology, was part-funded by the Science and Technology Facilities Council.