Exoplanets : 'To Infinity and Beyond'
Exoplanet is the name given to the planets which are outside our solar system. Yes, we are not alone. We just occupy a very small space in this vast universe, as we float around our familiar solar system. The first evidence as to exoplanets was found way back in 1917, but it was not recognized. The second detection occurred in the year 1988, but it was a couple of years before it was accepted. In 1992, there was valid confirmation, and it initiated devoted scientific research to find out and identify exoplanets, as well as other planetary systems.
1995, and a breakthrough: On October 6, 1995, 51 Pegasi b was discovered. It was a positive confirmation. It was the first exoplanet to be actually confirmed, signalling a scientific breakthrough, and the fact that it was approximately 50 light years away from us, made this discovery all the more exciting. It was only a matter of time before others were discovered, but the remarkable event of 1995 played a significant role in boosting our curiosity to explore the unknown.
TRAPPIST 1 family: On February 22, last year, 7 extraterrestrial planets were discovered orbiting around the cool red star, out of which, 5 were said to be the same size as Earth! This finding is definitely one of a kind, and currently researchers are engaged in gathering information about them. But it must be noted that in 2010, four extrasolar planets, viz. Upsilon Andromedae b, c, d and e, were found to orbit around Ï… Andromedae A. These planets were the size of Jupiter, and the first multiple planet system to be discovered in a multiple star system!
What colour are exoplanets? While exoplanets were discovered back in the nineties, it was only in 2013 that their colour was first determined. HD 189733b was the first exoplanet whose colour was discerned and subsequently confirmed to be deep dark blue. Since then the colours of many were determined, which varied according to their properties.
'Hot Jupiters': Some known exoplanets are massive, and were seen orbiting their suns from a very close distance. While this proximity to their suns defied planetary theories, it was found that the number of such planets were low. In short, the 'hot Jupiters', or as they were called, are a minority.
Kepler 186 f : Let's not forget this exoplanet, which is the first rocky one, in a habitable zone of other star (where the temperature is right for liquid water) to be discovered.
Planets, telescopes and the future: If you are wondering about the number of exoplanets to be discovered, the exact number would be 3797 (as of 1st July, 2018)! And there are more than 2000 candidate planets waiting for some confirmation. It was all possible with aid of the High Accuracy Radial Velocity Planet Searcher or HARPS (2004) which is a planet finding spectrograph, and which helped in finding hundreds of exoplanets. The Kepler space telescope (2009) too has its fine share, as it discovered thousands of them. The recently launched NASA programme (April, 2018) , headed by researchers from the Massachusetts Institute of Technology, called Transitory Exoplanet Survey Satellite (TESS), plans to scan the sky for two years in its bid to find exoplanets. We can hope for more good news, as the area which will be covered by TESS is 400 times larger than that of Kepler!
The universe is still a beautiful mystery, and we are just getting started on our wonderful journey. The discovery of exoplanets definitely fuels our desire to encounter species other than us earthlings, and explore the unknown parts of the universe where there are strange planetary systems, or red suns; here's to all things strange and new!
Post Written by - Lopamudra
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