I've had a telescope only six months, and the first object I looked at was the Orion nebula. I've been obsessed since, and I spend a lot of time thinking about what I am learning.
1. Chemistry is the same throughout the Universe. The visible matter in the universe is mostly H and He, and everything else was built by fusion within stars. Our planet and our bodies are built from star dust. The periodic table is the same everywhere.
2. Consequently, any other planet with photosynthetically-based life is going to have an atmosphere similar to ours – Mostly N2 gas (because it is a super stable molecule and will be plentiful on a planet with materials to support life), a good bit of O2, water (because as far as we can tell, water will be necessary to support complex life and ecosystems, noble gases if available (on Earth, Argon comprises 1% of the atmosphere), and trace gases from volcanic activity, respiration, and plant exudates. With the exception of the trace gases, the atmospheres on other living planets will seem like very much like ours.
3. We can tell how much and what kinds of atoms are in a star by examining the spectra of light emitted.
4. Extra-terrestrial biology – here we know nothing. What will their version of the DNA and RNA molecules look like? Will we make each other sick, or will our biochemistry be so different that we can’t make each other sick?
5. Dark matter and dark energy reveal that there are still a lot of physics to understand. That’s good. Honestly, we seem to have no handle on dark matter and dark energy whatsoever. We just know it’s out there, because the visible matter and the energy that we understand can’t explain a lot of things about galactic behavior.
6. A lot of visible matter is essentially invisible – brown dwarves. Our understanding of star and planet formation strongly indicates that galaxies are home to a huge number of brown dwarves, but they put out so little electromagnetic radiation, we have “seen” only a few of them.
7. Visible matter takes the same forms everywhere. Galaxies may differ in their sizes and beautiful details, but they really only come in three main flavors: elliptical/spherical blobs, flattened spirals, and dwarf galaxies that often lack much structure. They were all formed from large clouds of hydrogen and helium. They all have halos populated by globular clusters formed early in the galaxy’s development. The galaxies that are 10 billion light years away (Hubble telescope) look just like the ones that are 2.5 million light years away. Galaxies tend to occur in filamentous clumpy groups. Between these filaments of galaxies, there are vast regions of largely empty space. Space is like soap bubbles – a little bit of soap around large empty spaces.
8. As beautiful as the night sky is, there are really only a few types of things to observe in telescope. The universe contains galaxies, gas, dust, stars, groups of stars, star remnants, planets, and moons plus asteroids and comets. Everywhere you go, it’s the same stuff, made by the same processes. It's beautiful and fascinating, but there isn’t a lot of diversity in what physics and chemistry have made at the grand scale.
9. Stars are the same in all galaxies. Stars come in many different sizes, but their behavior and lifespans are very predictable, and these behaviors are the same in all observed galaxies. We love our sun, but it is nothing special. Eventually it will burn out most of its hydrogen, expand and become a red giant, swallow the Earth, die in spasms that release a huge gas/dust shell that will sweep out the entire solar system and Oort cloud, collapse into a white dwarf, and leave behind a beautiful ghostly gas/dust shell larger than the present solar system. Intelligent life elsewhere in the Milky Way will enjoy the pretty planetary nebula that was our solar system. The gas and dust will eventually be pulled apart by the gravity of other stars in the Milky Way galaxy and possibly become part of new stars.
10. A telescope looks back in time. Light travels at 300,000 km/s. The distance to the sun is 150 million kilometers, so it takes 500 seconds (about 8.33 minutes) for the sun’s light to reach Earth. A light-year is the distance light travels in a year. The closest star to our sun is Proxima Centauri, with is about 4.25 light-years away, so when we look at Proxima Centauri and its companion stars, we are looking back 4 years in time. When we look at the galaxies in the Virgo Cluster, we are looking back 50 to 65 million years. The light we see from those galaxies was emitted shortly after the dinosaurs went extinct and long before our human forebears began walking upright. The Hubble Telescope can photograph galaxies that are 13 billion years old, formed early in the development of the observable universe.
11. The moon is simultaneously cool and boring. The same side of the moon is always facing Earth, so the moon looks the same every month. It has no atmosphere, no wind, no rain, no running water, no life, no plate tectonics, and no active volcanism. If you went back in time two billion years ago, the moon would look nearly identical to how it looks now, except it would have a few less impact craters. It is just a very large pock-marked rock going around the Earth with negligible change over time.
12. While the moon may be boring in some ways, if you want to geta sure "wow" or an "Oh my God" from someone who hasn't looked through a telescope, your best bets are the moon, the Orion Nebula, Saturn, and Jupiter. Appreciation of dim galaxies must be acquired through knowledge and experience.
13. I had never heard of a globular cluster before I got a telescope, and it seems very few people have.
14. Astronomy has seasons. On Earth, spring is galaxy season. Summer is globular cluster and Milky Way season. I was sad when I first realized Orion and M42 were going away for six months.
15. The more observers you have waiting on you, the longer it will take to set up and align the scope.
16. Due to the humidity, there are very few summer nights in the southeast with good transparency and seeing. Don’t miss any decent skies.
17. Life is rare and precious. Everything we’ve been able to observe in the sky is just physics and chemistry, not biology. We don’t appreciate life enough, and we are oddly greedy and obsessed with possessions.
18. Astronomy hobbyists are often obsessive!
19. Speaking of obsession, aperture fever is a real and serious disease.
20. Magic is merely that which we don’t understand. The sky is full of well-understood physics and chemistry, but there is still magic out there – dark energy, dark matter, and extra-terrestrial life.
Edited by rjacks, 08 August 2021 - 12:58 PM.