Celebrating that event and the upcoming beggining of scientific operations, spaceurope had the opportunity to ask some questions to the Project Scientist of the mission, Dr. Malcolm Fridlund.
Here is the result.
Know more about COROT.
You might ask, how does a team spirit beahve on such exciting premisses?
According to Dr. Fridlund, it's “very high” and there are reasons for that: “the qualification of the spacecraft has been going perfectly and it is almost ready to start observations”.
After such a long wait one might ask if the spacecraft is really starting it’s work at 100%. The answer is yes. But, there are some conditions at this moment “the first two targets are primarily devoted to asteroseismology.
If you are waiting to see how does our galactic cousins home planet look like you’ll have to wait just a bit more...”The first 150 day pointing (which can observe small planets like the Earth) will start in April”
From then on there is a strong chance to spot through COROT’s eyes, an extrasolar planet like our own, on that event what will we, specifically, see?
“COROT detects the dip in the lightcurve of the star as the planet passes in front of it. In order to see a planet the size of our Earth, the dip will be 1 part in 10000 or smaller.”
Taking into account that the farest star where COROT can detect an orbiting body is located “Out to distances of several thousand light years”, just exercise your imagination...an A4 sheet, got it? Now divide it’s lenght, 297mm, by 5000 and it’s height, 210mm, by 2000.
You will get a square with 0,00594mm x 0,0105mm...
You really need to have great eyes to spot a dot that size on a piece of paper!
The quality of the first image matched with the ones predicted in simulations, what could only come as great news.
According to Dr. Fridlund, which kindly provided a brief description in order to help understanding what we are seing in that image, “it is a starfield with stars selected for calibration purposes. Each star is forming a small low resolution spectrum because there is a prism (or actually it is called a grism, a kind of combination of prism and grating) in front of the detector that breaks the light into different colors. One does this because a planet occulting a star will do so in all colours. An intrinsic diminishing of the flux of the star will do so differently in different colours.”
COROT will survey a vast region of space, does all that space, all those stars look the same? Or might there be a specific region where to look more carefully? “COROT can, for reasons of the orbit it is in, only look for long at two regions which are about 10 degrees in diameter. Within these regions COROT will select fileds of diameter 2.8 degrees (the field of view of the telescope)."
In terms of numbers, the mission’s Project Scientist make us dream about all the possible worlds awaiting us out there: “In each such field there are between 12000 and 6000 solar type stars which will all be observed. In the nominal mission this is 6 fileds with about a total of 60000 targets.”
And if you thought that this is like opening a tresor ark, that ain’t the whole story, “The extended mission will add about as many.”
Aren’t you smiling? I know I am...
Major gas giants should be the most probable to be detected, “they are the easiest to detect and we know that 10% of solar type stars have them.
Then about 2% of those will have occultations so we will pick up a number in each field.”
Exoplanets like our Earth are rare gems out there, and the time to distinguish a rocky planet like our own from another, let’s say, like Venus, it will still take a while, “for this we will need the Darwin (ESA) or TPF (NASA) missions in the future."
COROT is teaching the way for tomorrow’s misions, “the next step are bigger missions like COROT. NASA has one planned for 2009 called KEPLER which will observe only one field in the sky but for a longer period. The telescope is bigger so the number of stars will be maybe close to what COROT will sample, but fainter (more distant). The main advantage is to pick up planets in longer period orbits. After that will come the direct detection missions like Darwin and TPF which will observe the feeble light from the planet itself and analyse the light for atmospheric content and so-called bio-markers (signs of life as we know it)”.
Regarding scientific results “It will be a few months. I can not give it more exact than that at the moment”.
It is now a question of time to wait and see what the vastness of space has to reveal to COROT's querying vision.