10 Must-Know Things to Convince Anyone You Know Astronomy

Warnings: 1. You might get addicted to astronomy. 2. Others might notice and accuse you of being a geek/nerd/whatever. Just remember… this stuff has always been cool, and the rest of the world is finally figuring that out.

Why should anyone care a lick about astronomy? Well, it affects our daily lives in many not-so obvious ways. The fact that the sun rises in the east, the amount of daylight we have, the seasons… the tides…. all of this relates to astronomical influence.

Presented here are 10 basic things to know. These aren’t necessarily the weird things, but the basics if you want to start somewhere and claim to be at the beginnings of astronomy geekdom. For mind-blowing weird things, check out this article: https://seedscientific.com/astronomy-statistics/

If you think I should have included an 11 or 12, or want additional clarification on any of these 10, please comment all the way at the bottom of the post. I think anyone who walks into a party and can talk about these 10 things like they just came out of science class will have anyone convinced that you know your stuff. The cosmos is cool. Knowing this stuff will make you cool, too.

1. What phase of the moon is it?

Most people only know full vs new if at all. That’s okay. I put this one first on the list because it’s probably the item most relevant to our daily lives. The moon is responsible for the tides, and the phase of the moon also affects the tides: During the full and new moon phases, high tides are highest and low tides are lowest.

If you recreate near an ocean, tides are going to be relevant. I remember waiting as a kid for the tide to go out to see what fun seashells got left behind. Ok, not world-shattering stuff and yeah, you might never go near an ocean, but your life probably depends (at least a little) on someone else navigating the oceans to bring goods into your country. If you eat fish, those folks care, too.

Beyond new and full, the remaining phases are just fun to talk about and say. Try pronouncing the word “Gibbous.”

Too much? Then just know you can divide the phases into four primary ones: New Moon, First Quarter, Full Moon, and Last Quarter. It’s the secondary phases that are the weird ones to say (and remember): Waxing Crescent, Waxing Gibbous, Waning Gibbous, and Waning Crescent.**

There’s a neat mnemonic trick that I won’t try to explain… I’m just going to send you to the website with the cool visual: https://www.mnemonic-device.com/astronomy/moon/lunar-phases/

(with my own brief note: remember that the dog waxes, and the cat wanes. See that website and my note should make more sense!)

https://oceanservice.noaa.gov/facts/tidestudy.html

(** My hubby, who is not an astronomy geek, wonderfully puts up with all my geek and nerd-doms and always reads my blog posts before I post. When he read this section, he asked, “But what about the half moon?” I must have looked at him like he sprouted a second head or morphed into the Terminator or something.

Turns out, “normal people” (as he refers to himself) often call both the First and Last quarter a “half moon.” The difference is which side the half is on. First quarter is lit on the right side from the vantage point of Earth—the “D” if you watched the mnemonic cool video visual and the Last Quarter is lit on the left.)

2. Be able to look up and point out a constellation or two.

Like Orion in the winter.

This really only serves as a method to continue to help build your Astronomy geek cred. Knowing the constellations doesn’t have a lot of practical use today, although back in the day—the really long-ago day—knowledge of constellations was required to navigate anywhere. (Today, we all navigate with GPS in our phones—thanks to satellites, something we’ll talk about in another post.)

Yes, this was more practical in ancient times when stars were used for navigation and keeping track of the calendar (like when to plant crops). Today, this is more for historical knowledge and fun than anything else.

If you can walk out on a starry night, and pick out some constellations and stars, it will certainly help your astro geek cred!

3. Any Astronomy geek should be able to name all the planets.

(And some moons, major asteroids, and dwarf planets (besides Pluto) – but we’ll get to those later)

Why? In a few decades, we might visit our grandkids or great-grandkids there for the holidays. Again, this is a little more about building that geek cred.

Having problems remembering the names of the planets? Mnemonics to the rescue!!

“My Very Excellent Mom Just Served Us Noodles.”
(Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune)

..and while researching links for this blog post, I learned a new mnemonic myself to remember the order of the planets by size (Largest to smallest).

“Just Sit Up Now Each Monday Morning.”

Of course, with two planets beginning with “M” you’ll have to know which is which. Hopefully, it isn’t too taxing on the brain to remember that Mercury is the smallest planet, closest to the Sun.

4. Speaking of moons… it’s good to know which planets have moons and which don’t.

Since someday, we might rely on those moons for resources!

Mercury and Venus have no moons. Earth, our home and the 3rd planet, has one. Mars, the 4th planet, has two. See a pattern emerging? Further out in the solar system, the larger planets have a whole pile of moons. Why is that?

Smaller planets don’t have as much gravitational influence, for one. And the Sun’s gravitational influence this close to it plays a role, as well.

Remember that Phobos and Deimos are the two moons of Mars.

“I Eat Green Carrots” is a nice mnemonic to remember the 4 Galilean moons of Jupiter: Io, Europa, Ganymede, Callisto

“Met Dr. Thip” is one for the moons of Saturn: Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Iapetus, and Phoebe.

5. Don’t forget about the dwarf planets!

Yeah, I know some people don’t like that Pluto was “demoted.” But think of it this way… Pluto’s demotion brought to light the fact other fantastically interesting objects exist: the dwarf planets. You might not know about Makemake or Haumea otherwise!

While we’ve known about the largest asteroids in the asteroid belt, like Ceres, their elevation to dwarf planet makes them even more popular! The spacecraft Dawn even visited Ceres (and Vesta… a former dwarf planet that was demoted).

6. It’s only been in relatively recent times that we know about galaxies…

They were thought to be individual stars or nebula prior to the early 20th century.

Before that, they classified a lot of these galaxies as “nebulae.” They were fuzzier than stars. Some are indeed what we currently know now as nebulas, but the term “nebulae” was used to describe all nebula-like objects back in the day.

In the very early 1900s, as telescopes were improving, these “nebulae” objects were studied in more detail. Edwin Hubble is the one who officially gets credit for proving that there are other galaxies beyond our Milky Way. What does he get in return? A fancy space telescope named after him.

7. Only a small fraction of the energy that the Sun generates and emits gets to us on Earth.

Talk about waste! (And talk about how we could harness that if we only had the engineering skills….)

On a beautiful day, with no clouds, and the sun shining, it’s hard to remember that the sun is only a small circle in our sky. That small circle is really a ginormous sphere, and the energy it produces is radiating out equally in all directions. Here on Earth, we’re only receiving a small portion of that energy!

The sun is essentially a massive fusion reactor. Trying to put the numbers into perspectives that make sense… the sun produces the equivalent of 38,460 septillion watts (3.846×10^26 W) per second. (What’s a septillion? I’ll assume you’re familiar with million, billion, and trillion. Then there’s quadrillion, quintillion, sextillion and THEN comes septillion. It’s a REALLY large number.)

Approximately one one-billionth of that total energy reaches Earth. A lot of that energy doesn’t get used… the clouds reflect a bunch back into space. The Earth itself reflects even more back into space.

So we can use what we can here… and maybe someday we’ll be technologically advanced enough to build a Dyson’s sphere to harness the rest.

https://energyeducation.ca/encyclopedia/Solar_energy_to_the_Earth

8. Comets and asteroids are our best chance for figuring out what happened in the beginning…

They brought Earth carbon and water when the Earth was formed, two important items necessary for all life as we know it! Scientists think that in Earth’s earliest days, asteroids and comets rained down like crazy on Earth, delivering these needed materials. In fact, we think that a substantial part of Earth’s water came from a large number of small comets. Therefore, studying comets and asteroids is like studying the early days of life.

Plus, the materials of the asteroids and comets were the materials that formed the building blocks of our planets. And… we might use some of that material as we go out and explore the rest of the solar system some day.

9. Speaking of which… know about the next upcoming meteor shower.

And know what they are and why they happen at the same time every year.

Meteor showers occur when dust particles, not big rocks, left over from the tails of comets or asteroids enter the Earth’s atmosphere at a very high speed.

It happens at about the same time each year because Earth passes through dust trails left by asteroids or comets as Earth moves through the same location each year.

Here’s a list specifically for 2021:
https://www.go-astronomy.com/solar-system/meteors.php

And Wikipedia has a longer list:
https://en.wikipedia.org/wiki/List_of_meteor_showers

10. We’re not even close to the center of our Galaxy… and that’s probably a good thing!

Because at the center is a supermassive black hole! We’re about 25,000 light-years away in what is known as the Orion Arm. If we were an observer looking from outside our galaxy, we’d see that the Milky Way is a spiral galaxy with several arms rotating around it.

That supermassive black hole is part of the central bulge and that’s where all the old stars hang out. Out here in the arms are where new stars are formed. Besides our Orion arm, there is also the Cygnus arm, the Perseus arm, and the Sagittarius arm. I think there are other arms, too, but I don’t know if they’re named.

But let’s talk more about that very center… that supermassive black hole is super massive because it has the mass of 1 million stars! It also has a name: Sagittarius A*.

The James Webb Space Telescope, launching sometime later this year, will study it among other things!

Other general references:

https://www.universetoday.com/15959/interesting-facts-about-the-solar-system/

https://sciencetrek.org/sciencetrek/topics/astronomy/facts.cfm