Glossary

Minor planets revolve around the Sun, just like the planets but their masses are much lesser than that of planets. They are much smaller and their shapes need not be spherical. The first minor planet, Ceres was discovered in 1801. You might know that Pluto, which was earlier considered as planet was recently (in 2006) classified as a minor planet. There are more than 7 lakh minor planets, usually they are identified by combination of numbers and alphabets but  21,009 have names. Many of them being named after people who do interesting work. So far nine Indians have the honor of a minor planet being named after them! It includes the chess grandmaster Viswanathan Anand; physicist Hansa Padmanabhan; zoologist Sainudeen Pattazhy; computer scientist Akshat Singhal; inventors, Vishnu Jayaprakash, Anish Mukherjee, Debarghya Sarkar, Hetal Vaishnav and Madhav Pathak. Their discoveries and innovations are very interesting. Try to find out about their discoveries! Many of them were very young, just finishing school or in college when they got the planets named after them! If you work hard, you too have a chance of getting your name on a celestial object!

The bigger minor planets, which are almost spherical in the shape are called dwarf planets. Both Ceres and Pluto are dwarf planets (Figure 3). Pluto even has a moon named Charon.
 

Figure 3: Dwarf planets
 

Figure 3a: Ceres
(Credit: By Justin Cowart - Ceres - RC3 - Haulani Crater, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=49700320)

Figure 3b: Pluto and its moon Charon
(Credit: By NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute - https://www.nasa.gov/mission_pages/newhorizons/images/index.html?id=371389 (see also http://photojournal.jpl.nasa.gov/catalog/PIA19966), Public Domain, https://commons.wikimedia.org/w/index.php?curid=44378681)