In the past century or so, astronomy has been broadly split into two camps — observational astronomy (using telescopes and cameras to collect data about the night sky) and theoretical astronomy (using that data to analyze, model and theorize about how objects and phenomena work)..
In the most rigid sense: Astrophysics creates physical theories of small to medium-size objects and structures in the universe.
Astronomy measures the positions, luminosities, motions and other characteristics of celestial objects.
Cosmology covers the cosmos' largest structures and the universe as a whole..
You can read more about cosmology and the foundations of the Big Bang model in Wilkinson Microwave Anisotropy Probe's Introduction to Cosmology by NASA.
For more answers to common cosmology questions, go to NASA's Ask an Astrophysicist page.
What came before the Big Bang.
Because of the enclosed and finite nature of the universe, we cannot see "outside" of our own universe.
Space and time began with the Big Bang.
While there are a number of speculations about the existence of other universes, there is no practical way to observe them, and as such there will never be any evidence for (o.
Launched in November 1989, NASA's Cosmic Background Explorer(COBE) took precise measurements of radiation across the sky.
The mission operated until 1993.
Although NASA's Hubble Space Telescope is probably best known for its astounding images, a primary missionwas cosmological.
By more accurately measuring the distances to Cepheid variables, stars .
Humanity's understanding of the universe has evolved significantly over time.
In the early history of astronomy, Earth was regarded as the center of all things, with planets and stars orbiting it.
In the 16th century, Polish scientist Nicolaus Copernicus suggested that Earth and the other planets in the solar system in fact orbited the sun, creatin.
Cosmology studies the universe on a larger scale.
It studies the universe as a whole.
Cosmology differs from astronomy in that the former is concerned with the Universe as a whole while the latter deals with individual celestial objects.
So this makes clear the difference between Astronomy, Astrophysics, and Cosmology.
Cosmology tends to be concerned with scales between the size of the universe and the largest strucutres in it.
Astrophysics looks a bit more at galaxies and smaller.
A second difference I've noticed is that Cosmology is largely concerned with the dark sector (Dark Matter & Dark Energy) whereas Astrophysics predominantly (but not exclusively ..
is that cosmology is the study of the physical universe, its structure, dynamics, origin and evolution, and fate while cosmogony is the study of the origin, and sometimes the development, of the universe or the solar system, in astrophysics, religion, and other fields.
