Astronomers uncover alien world so 'extraordinarily dark' it makes coal look shiny

The blackest planet: Astronomers uncover alien world so 'extraordinarily dark' it makes coal look shiny
By Daily Mail Reporter
Last updated at 12:00 PM on 12th August 2011

Astronomers have discovered the darkest known planet.
The exoplanet, known as TrES-2b, reflects less than 1 per cent of light, which makes it darker than any other planet or moon.
The discovery, detailed in the journal Monthly Notices of the Royal Astronomical Society, was made by analysing data from Nasa's Kepler spacecraft, which provides extremely precise measurements on the brightnesses of faraway stars.

Black planet: This artist's impression shows TrES-2b, a planet so hot it glows red like embers, but is also officially the darkest known planet'TrES-2b is considerably less reflective than black acrylic paint, so it's truly an alien world,' David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA) told Science Daily.
TrES-2b, a gas exoplanet roughly the size of Jupiter, is around 750 light years away and was discovered in 2006 by the Trans-Atlantic Exoplanet Survey; hence its less-than-catchy name.

The reason it differs from other similar-sized planets is that Jupiter, for example, is surrounded by ammonia clouds that reflect more than one third of its sunlight.TrES-2b has no ammonia clouds to reflect light because it is extremely hot.
It orbits its star - GSC 03549-02811 - at a relatively intimate five million kilometres, which means it exhibits temperatures of up to 1,000C.
Instead, it has an atmosphere made up of chemicals such as vaporized sodium, potassium and gaseous titanium oxide, which absorb light, but that still does not explain the planet's extreme




Space spy: The team made their discovery while working through data from NASA's Kepler spacecraft, one of the world's most powerful telescopesHowever, TrES-2b is not entirely black. It's extreme heat means it gives off a faint red glow, reminiscent of burning embers.
Kipping and his team arrived at the discovery by measuring the light TrES-2b emitted as it orbited its star, much like our moon does with earth, studying both the 'visible' side and its 'dark' side during orbit.
'By combining the impressive precision from Kepler with observations of over 50 orbits, we detected the smallest-ever change in brightness from an exoplanet: just six parts per million,' said Kipping.
'In other words, Kepler was able to directly detect visible light coming from the planet itself.'

Read more: http://www.dailymail.co.uk/sciencetech/article-2025150/TrES-2b-The-blackest-planet-space-uncovered-astronomers.html#ixzz1UpBRBnVi