By Jonathan Amos.
The science correspondent of the British Broadcasting Corporation.
The image is from the Europlanet-Science Office.
The image caption is.
The European Space Agency member states selected the artwork of Ariel.
The European industry has signed a 200m contract to build a space telescope.
The observatory will study planets around other stars to understand how they formed.
The expectation is that the project will be launched in 2029.
Much of the hardware assembly will be handled by the UK.
This decade is shaping up to be a golden era for the study of extra-solar planets.
Since the mid 1990s, more than 5,000 worlds have been discovered, but so far we've done little more than count how many are out there.
In the next few years, the investigation will move to their characterisation, asking how their atmospheres function if they have them.
The US space agency will launch a $10 billion James Webb space telescope later this month, which will take an in-depth look at many tens of exoplanets, and "fingerprint" the gases in their atmospheres.
For about 1,000 exoplanets, Ariel will do something similar.
You could think of him as a mini-James.
"Webb is a general purpose observatory and it will be doing many other things than just studying exoplanets." It will be all about this one job for Ariel. He told the news that one hundred percent of its observing time would be devoted to characterising exoplanet atmospheres.
The caption is media.
The space telescope should launch in 2029.
2029 is the launch year.
Mission lifetime is 4 years.
500 kilogram payload mass
The launch mass is 1,500 kilogram.
A special observing position is 1.5 million km from Earth.
The acronym is "Ariel" for Atmospheric Remote-Sensing.
The telescope was selected for development by European Space Agency member states, since when the project has been undergoing various feasibility studies.
The new contract will allow the design to be pushed forward and the necessary technologies to be finalized.
As the planet moves in front of the star, it will be monitored by the astronomer to see how the starlight changes.
This will be a sign of the chemistry of the exoplanet's atmosphere.
A large type-catalogue is the goal of the man.
Astronomers want to know what's typical for the kinds of worlds that are out there, to establish as far as possible what might be regarded as the "standard model" for planetary systems.
We see a lot of places that look like our Solar System.
The facility in the UK that will be used for important structural and avionics work will be located in Toulouse, France.
The business end of the observatory will be assembled and tested at RAL Space on the Harwell Campus.
All over Europe, components will come from.
The mirror system is going to be a challenge.
This will be all aluminum and will have to operate at very low temperatures.
The telescope will be made out of the same material and shrink at the same rate when it gets very cold. "If it's perfectly aligned when warm, it should stay perfectly aligned when cool," said Paul Eccleston, the chief engineer at RAL Space.
The challenge is to be able to make a large, 1.1m diameter mirror and to be able to make a flawless block of aluminum that has no differences in grain size.
