Transcript Astronomy

EARLY ASTRONOMY
Early cultures identified celestial objects
with gods and spirits. They related these
objects (and their movements) to phenomena
such as rain, drought, seasons, tides, and
food.
It is generally believed that the first
"professional" astronomers were
priests, and that their understanding
of the "heavens" was seen as "divine".
Ancient constructions with
astronomical alienations (such as
Stonehenge) probably fulfilled both
astronomical and religious functions.
The study of celestial bodies also served as
Navigational guides.
Astrologers studied the relative position of the
Planets and stars to make predictions concerning
a persons destiny.
Astronomy is not to be confused with
astrology, a pseudoscience that attempts to
predict a person's destiny by tracking the
paths of astronomical objects. Although the
two fields share a common origin, they are
quite different; astronomers embrace the
scientific method, while astrologers do not.
Astronomy, which etymologically means "law of
the stars", (from Greek: αστρονομία = άστρον +
νόμος) is a science involving the observation and
explanation of events occurring outside Earth
and its atmosphere. It studies the origins,
evolution, physical and chemical properties of
objects that can be observed in the sky (and are
outside the earth), as well as the processes
involving them.
Astronomy is one of the few sciences where
amateurs can still play an active role, especially in
the discovery and monitoring of transient
phenomena
In its earliest days, going back to ancient Greece
and other ancient civilizations, astronomy consisted
largely of astrometry, measuring positions of stars
and planets in the sky
Later, the work of Kepler and Newton paved the way
for celestial mechanics, mathematically predicting
the motions of celestial bodies interacting under
gravity, and solar system objects in particular. Much
of the effort in these two areas, once done largely
by hand, is highly automated nowadays, to the
extent that they are rarely considered as
independent disciplines anymore.
Ever since the twentieth century the field
of professional astronomy has tended to
split into observational astronomy and
theoretical astrophysics.
A. Observational astronomy is concerned mostly with getting data,
which involves building and maintaining instruments and processing the
resulting data; this branch is at times referred to as "astrometry" or
simply as "astronomy."
B. Theoretical astrophysics is concerned mainly with
figuring out the observational implications of different
models, and involves working with computer or analytic
models.
The fields of study are also categorized in
another two ways: by "subject", usually according
to the region of space (e.g. Galactic astronomy) or
"problems addressed" (such as star formation or
cosmology); or by the way used for obtaining
information.
•Astrobiology: the study of the advent and
evolution of biological systems in the universe.
•Astrometry: the study of the position of objects in
the sky and their changes of position. Defines the
system of coordinates used and the kinematics of
objects in our galaxy.
•Cosmology: the study of the
universe as a whole and its
evolution.
Galactic astronomy: the study of the structure and
components of our galaxy and of other galaxies
•Extragalactic astronomy: the study of
objects (mainly galaxies) outside our galaxy.
Some topics include:
Supernovae
Quasars
Radio galaxies
Groups and clusters of galaxies
•Planetary Sciences: the
study of the planets of the
solar system.
Stellar astronomy: the study of the stars
Stellar evolution: the study of the evolution of stars from
their formation to their end as a stellar remnant.
•Star formation: the study of the condition
and processes that led to the formation of
stars in the interior of gas clouds, and the
process of formation itself.
Archaeoastronomy (also spelled Archeoastronomy)
is, as the name implies, the combination of
astronomical and archaeological studies.
Astrochemistry is the study of the chemicals
found in outer space, usually in molecular gas
clouds, and their formation, interaction and
destruction. As such, it represents an overlap
of the disciplines of astronomy and
chemistry.