Friday, October 18, 2013

’Earth-Like’ Asteroid Devoured by Dead Star

The Hubble Space Telescope has recorded an intriguing event some 150 light-years from Earth.

A large asteroid was pulled into the White Dwarf star (named ‘GD 61’ by astronomers) and utterly destroyed. This is not an unusual event, as even dead stars still exhibit a very high level of gravity. However, scientists are interested because the chemical signatures left in the star’s atmosphere indicate the presence of water and a rocky surface, both considered to be key building blocks for the creation of life on our planet.

Until this event was observed, water and a rocky surface had never been found together on an object outside our solar system.

The asteroid consisted of the elements magnesium, silicon, iron and oxygen, all of which are usually found in rock minerals, but scientists believe that the abundance of oxygen indicated the heavy presence of H20.

The object was at least 90KM across and as much as 26% of that is thought to have been water. Earth is considered to be just 0.02% water.

This discovery is important because it gives scientists a vindicating glimpse of how inhabitable environments may have been formed, receiving key components (such as water) from outside sources such as meteorites.

It is thought that water first arrived on our planet by similar means and that other planets in the GD 61 system would once have received water this way as well. According to BBC News, scientists consider the presence of rocky planets in the GD system to have been “very likely”.

Scientists have observed over 1,000 planets outside our solar system, but none is thought to contain water.

Closer to home, some planets and heavenly bodies are thought to contain water. Mars is considered by many to once have had liquid water, but if this is still the case, it is a greatly reduced amount.

Elsewhere, Jupiter’s moon Europa raises a tantalizing prospect that there are oceans under its icy surface. This has led to some convincing research into the possible presence of ocean currents there. However, Europa is not alone, its fellow moons Callisto and Ganymede have also been suggested as candidates for liquid water.

In addition, Rhea (moon of Saturn), Titania (moon or Uranus), Oberon (also orbiting Uranus), Triton (moon of Neptune), Pluto (dwarf planet), Eris (dwarf planet), Sedna (possible dwarf planet) and Orcus (another possible dwarf planet) are all speculated to have oceans, some of which may be in contact with the rocky core of the respective body, which would hypothetically result in a steady stream of minerals and salts into the water – an important factor in creating life.

Saturn’s moon Enceladus has geysers, which is seen as proof of the presence of water or at least water vapours. It has even been theorized by some that Neptune contains oceans of liquid diamond.

The heavy presence of water on this asteroid is a vital clue for scientists and their understanding, not only of the cosmos, but also of how our home planet came into being.



’Earth-Like’ Asteroid Devoured by Dead Star