He is more of a great public figure than he is a great scientist. He hasn't really done any significant scientific work besides that.
Neil deGrasse Tyson (born October 5, 1958) is an American astrophysicist, cosmologist, author, and science communicator. Since 1996, he has been the Frederick P. Rose Director of the Hayden Planetarium at the Rose Center for Earth and Space in New York City. The center is part of the American Museum of Natural History, where Tyson founded the Department of Astrophysics in 1997 and has been a research associate in the department since 2003.
From 1995 to 2005, Tyson wrote monthly essays in the "Universe" column for Natural History magazine, some of which were published in his book Death by Black Hole (2007). During the same period, he wrote a monthly column in Star Date magazine, answering questions about the universe under the pen name "Merlin". Material from the column appeared in his books Merlin's Tour of the Universe (1998) and Just Visiting This Planet (1998). Tyson served on a 2001 government commission on the future of the U.S. aerospace industry, and on the 2004 Moon, Mars and Beyond commission. He was awarded the NASA Distinguished Public Service Medal in the same year. From 2006 to 2011, he hosted the television show NOVA ScienceNow on PBS. Since 2009, he has hosted the weekly podcast Star Talk. In 2014, he hosted the television series Cosmos: A Spacetime Odyssey, a reboot of Carl Sagan's 1980 series Cosmos: A Personal Voyage. The U.S. National Academy of Sciences awarded Tyson the Public Welfare Medal in 2015 for his "extraordinary role in exciting the public about the wonders of science". More: en.wikipedia.org.