A huge number of comets are hurtling through the solar system at any time for their rendezvous with the Sun. There has been a concerted effort by space agencies to study these celestial visitors, with some of them whizzing close by Earth. One such joint project is the Solar and Heliospheric Observatory (SOHO), a joint project of the European and US space agencies. Recently, SOHO discovered its 3,000th comet, thanks to Worachate Boonplod, a citizen scientist from Thailand. In fact, almost 95 per cent of SOHO comets have been found by volunteers like Boonplod with a passion for astronomy. Through an array of satellites and space-based telescopes, the solar disk and its surrounding environment is observed constantly; the stream of data and images collected by SOHO is then downloaded by its army of amateur astronomers with their internet connections. They scour the data and study the images for signs of a comet, using an online SOHO guide and photo-editing software to alyse the images. Discovery of a comet is at once reported after measuring its position. Thanks to the internet and latest smartphone apps, citizen scientists can help gather and process data, which in turn can be alyzed by professiol researchers. Apart from astronomy, online communities of citizen scientists are collaborating in studies as diverse as search for extra-terrestrial sigls, global warming, tural resource magement, animal and plant studies and D research. In the history of Science, progress came through amateurs before the professiol scientist took over in the 20th century. Science became ‘Big Science’, funded by universities, governments and multi-tiol consortiums. Thanks to information technology, the pendulum is now swinging back in the 21st century, allowing enthusiasts to contribute to scientific progress once again.