Having just declared my intention not to cover astronomy,
here I start right in with it! Well, I want to make a few abstract generalizations
about the subject. The first is a commentary on the idea of an observational
science in a Quantum Mechanical millieu. Until recently, all
astronomical observations were made by detecting light emitted
by distant objects a long time ago. Nowadays Astronomers detect the full
range of the electromagnetic spectrum, from long-wavelength radio waves
to gamma rays, as well as the odd neutrino,
but the qualitative picture hasn't changed: a virtual quantum is emitted
at a distant source and absorbed here on Earth; by measuring the relative
intensity of such quanta arriving from different directions, we get a picture
(literally) of the Universe around us. On the one hand, we cannot detect
the photons without annihilating them; in this sense the act of measurement
interferes with the system being measured, as Quantum Mechanics has taught
us to expect. On the other hand, it is reasonable to expect that our interference
is only with the photons themselves, not with their distant emitters; and
in this sense the Astronomer is an awfully good approximation to the classical
observer.
The next philosophical point is that the photons we detect on Earth may have been "in transit" for millions or even billions of years, depending upon how far away their source was when they were emitted. Thus as we look outward to the distant galaxies we are also looking backward in time. Sort of. So if we see the same sort of spectrum (including, for instance, the ubiquitous hydrogen atom emission lines) from a star in another galaxy as we do from Sol, it means that the "Laws of Physics" are pretty much the same here and now as they were there and then. This gives a comforting sense of stability and permanence, even if our individual destinies are short and unknown.
In recent decades humans have developed the technical ability to go and have a closer look at other bodies in our own Solar System; this is absolutely delightful and has rekindled interest in Astronomy among the people who end up paying for it, better yet! However, it probably will come to be known by a different name ( e.g. planetology) simply because of the increased scope of the Experimenter's capacity to interfere with the Observed. Ultimately, humans will again set foot on other worlds [as we did back in 1969 and the early 1970's - doesn't anyone remember?!] and carry the Laboratory to the stars where whole new categories of information can be gathered. However, the sheer distance of other stars makes patience a virtue in such plans....