How Planets are discovered ?

We listen to a lot of news regarding discovery of new planets time to time. Ever wondered how so many planets are discovered ? How do we determine their sizes even though they are so far away?

Well, there are two methods that are used popularly. The most common one that a lot of astronomers use is the Transit Method. Long gone are the days of Galileo or William Herschel method of using a telescope and sitting for hours and hours to possibly observe a planet. Nowadays, the integration of telescope with data science has made it much more easier. So, let's see how it works ..

But before further diving in, a common question that our mind is provoked by is why do we need to even waste our time looking at sky to discover random planets? Well, the main reason is to find a possibility of life on other planets and to study their effects on other celestial beings. Yes, there is still a slight chance that there is some life out there and honestly, the discovery of even one such life could change the entire course of human history. 

 

         Picture of the beautiful Gas Giant named GJ 504b (2013)

Onto the transit method, A transit occurs when a planet comes in between the star and the observer. So, when a planet passes in front of the star, it blocks out some of the light and the telescope instantly picks up the brief decrease in brightness. The brief decrease in brightness, also known as depth can be further plotted with time to determine the size of the planet in relation to the stars.

The above picture signifies the thing I discussed above. Furthermore, besides determining the depth it can also be used to determine the distance of the exoplanet's orbit. But the main problem that scientists face is determining the actual size as the picture only gives us the size with respect to the Star. To solve this issue, the telescope have a catalog which contain information about almost millions of stars. One of the properties of this catalog is Stellar Radius which is used to further find the actual size of the planet. Besides this, we can also learn more about the exoplanet's atmosphere and it contents. As the planet passes the star, the light that passes through it can also be analyzed to find details about the atmospheric contents that caused the dispersion. The data received from this can be further used to analyze habitability of the planet. The size of the planet, distance from the stars and the atmospheric contents help us the answer the big question is life possible on that planet? 

There is also another method named Wobble method which is used to determine the size of the very huge planets orbiting real close to the stars. The concept of doppler effect is used to find the exact details about it. I will discuss this in another of my blog. 

Well finally, what's the use of data science here ? It's pretty obvious, the huge catalog of millions of stars which is used to determine the size of different planets, the plotting of graph, the exact value of the depth time and finally archiving the data. Everything is related to data science. Pretty much ignored but the beautiful combination of astronomy and data science really has helped the scientist to properly discover more than 5000 exoplanets till now. That's it for this blog! Hope you gained an insight on this wonderful concept.

Stay tuned and THANK YOU..