Diamond planet found by French-US team

Twinkling stars are not the only diamonds in the sky. Scientists reported Thursday the existence of a "diamond planet" twice the size of Earth and eight times its mass, zooming around a nearby star.

Diamond planet found by French-US team
Photo: European Southern Observatory

In fact, this is not the first diamond planet ever discovered, but it is the first found orbiting a sun-like star and whose chemical makeup has been specified.

The discovery means that distant rocky planets can no longer be assumed to have chemical constituents, interiors, atmospheres or biologies similar to those of Earth, said lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy.

The planet was first observed last year — but researchers initially assumed it was similar in its chemical make-up to Earth.

It was only after a more detailed analysis that the French-American research team determined the planet, dubbed 55 Cancri e, is vastly different from our own.

The planet "appears to be composed primarily of carbon (as graphite and diamond), iron, silicon carbide, and, possibly, some silicates," the authors wrote in a statement ahead of their findings' publication in the US journal Astrophysical Journal Letters.

"The surface of this planet is likely covered in graphite and diamond rather than water and granite," Madhusudhan noted.

In fact, the planet appears to have no water at all. And as much as a third of the planet's substantial mass could be made of diamond, a super-dense compound of carbon.

In comparison, the Earth's interior is rich in oxygen and very poor in carbon, explained study co-author Kanani Lee of Yale.

The researchers estimated the planet's radius with data collected while it was transiting in front of its star.

That information, combined with an estimate of its mass, was used to model the planet's chemical composition, based on a calculation of just what elements and compounds could result in that specific size and mass.

The planet's orbit around its star is lightning fast — a year lasts just 18 hours. And because it is so close to its star, surface temperatures average 3,900 degrees Fahrenheit (2,148 Celsius), rendering it completely inhospitable to life.

But the planet — just 40 lightyears away from Earth in the Cancer constellation — opens new avenues for studying geochemical and geophysical processes of Earth-sized planets outside our solar system.

The high levels of carbon may have implications on how volcanoes and earthquakes work and how mountains form — and add to the growing body of evidence that planets are far more numerous and varied than initially imagined.

"Stars are simple — given a star's mass and age, you know its basic structure and history," said David Spergel, a Princeton University astronomer.

"Planets are much more complex. This 'diamond-rich super-Earth' is likely just one example of the rich sets of discoveries that await us as we begin to explore planets around nearby stars."

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Eclipse: What you need to know to catch Friday’s blood moon in France

The stars are set to be outshone by a Blood Moon in the longest total lunar eclipse of the 21st century which will be visible all across France on Friday. Here's what you need to know about this astronomical phenomenon and how to see it at its best.

Eclipse: What you need to know to catch Friday's blood moon in France
Illustration photo: A full moon and the Eiffel tower are seen in Paris on July 3, 2015. AFP
What will the eclipse look like?
In a lunar eclipse the moon appears darkened as it passes into the Earth's shadow. 
During Friday's eclipse, the moon will gradually take on a reddish hue as it advances into the Earth's shadow and the colour will look “a little like when the sun sets on the horizon”, according to a spokesman for the French Association of Astronomy Clément Plantureux. 
But it seems the exact shade of red that will appear is hard to guess. 
“Dark red, intense or coppery, it's difficult to predict,” Pascal Descamps, astronomer at the Paris Observatory told BFM TV. “This red tint comes from a filtering effect of the Earth's atmosphere… so the intensity of the coloring will depend on the state of the atmosphere.”
According to NASA scientists: “The exact color that the moon appears depends on the amount of dust and clouds in the atmosphere. If there are extra particles in the atmosphere, from say a recent volcanic eruption, the moon will appear a darker shade of red.”
Illustration photo: AFP
Why does the moon turn red in a Blood Moon eclipse?
The red moon is possible because while the moon is in total shadow, some light from the sun passes through Earth's atmosphere and is bent toward the moon.
While other colors in the spectrum are blocked and scattered by the Earth's atmosphere, red light tends to make it through easier. 
What time will you be able to see it?
In mainland France, the eclipse will be visible from 10 pm – 10.30 pm and it is expected to last until nearly 12.30 am. 
“We have to wait for the moon to rise a little above the horizon to be able to see it, with the beginning of the eclipse taking place before the moon rises,” Descamps said, adding that in French territories such as Reunion Island in the Indian Ocean the whole of the eclipse will be visible from beginning to end. 
In mainland France, however, “we will only see the end”. 
And remember to try and catch the event as soon as you can because the moon will only be in a state of total eclipse until 11.15 pm when it will start to emerge and regain its normal appearance. 
Those in the south of the country will be better placed to see the blood moon than those in Paris or the north. 
“The beginning of the phase of total eclipse will be visible only in the east of a diagonal line that links Bordeaux, Paris and Lille”, said the site Sciences et Avenir.
So if you are Brittany or Normandy don't get your hopes up. Of course everything depends on the weather (see below).
Illustration photo: AFP
How to get the best view 
It's important to have a clear view of the horizon towards the south east, astronomers told the French press. 
That means that if you're in Paris your best chance of seeing the phenomenon is to go to the top of the Eiffel Tower or Tour Montparnasse while those outside of the capital would benefit from leaving areas with forests or hills
But don't worry, even if you don't manage to find a perfect spot, you'll still be able to get a good view of the red moon as it rises in the sky. 
If you're something of an astronomy buff it's probably worth investigating one of the 130 astronomy clubs in France which will be holding events for the public in honour of the occasion. 
So, what is the weather forecast?
Naturally a lack of cloud will help with seeing the eclipse at its best so we've taken a look at the weather forecast. 
Unfortunately for those in the north of the country storms are predicted while the east and most of the south  and south-east is looking clear. This was the latest weather forecast on Friday morning.
Should I protect my eyes?
There's no need to take precautions when it comes to looking at the eclipse, scientists have said. In fact, it will be easier to look at than a normal full moon because it won't be as bright due to the lack of sunlight. 
And you don't have to worry about having a telescope to get a good view, with astronomers saying that there will be a very good view without the need for special equipment.