|The Milky Way Galaxy. Public domain image. SOURCE.|
It differs from cosmology (which is Tuesday's subject for the A-Z Challenge) in that it usually focuses on physical and chemical properties of the universe, while cosmology deals more with the nature and laws of the universe. The line between the two is not that great, however, and they're both part of astronomy, which is an even larger field that includes the study of everything outside of Earth's atmosphere.
A few current research subjects in astrophysics are black holes (points where gravity is so powerful that light, traveling at its tremendous 299,792,458 meters per second, cannot escape), planet, galaxy, and star formation, the interstellar medium (gas, dust, charged particles, and anything else between stars), dark matter and energy (dark energy is thought to constitute 70% of the universe and dark matter 25%), and the possibility of life in the universe beyond Earth (in addition to how it may have arrived here on Earth, if it did so).
Neil deGrasse Tyson
|Public domain image. SOURCE.|
He is the host of StarTalk Radio, NOVA ScienceNOW, and the two NOVA programs The Pluto Files and Origins (both based on his books) and was given the NASA Distinguished Public Service Medal. In addition, he has written many scientific papers. He is also the host of an upcoming 13-part sequel to Carl Sagan's Cosmos: A Personal Voyage, due to air in 2013.
On a less scientific note, People declared Neil deGrasse Tyson the Sexiest Astrophysicist Alive in 2000, and the International Astronomical Union named an asteroid after him--13123 Tyson.
Video narrated by Neil deGrasse Tyson about the most astounding fact to the universe:
What do you think of astrophysics? And as today is the kickoff of the A-Z Challenge: how is the Challenge starting off for you?
-----The Golden Eagle