• Luke

If you have been out at dusk lately You may be noticing the brightest star that appears over the southern horizon just after sunset. This “star” is actually the planet Jupiter!

Infrared view of Jupiter

Jupiter is the largest planet in our solar system at 11.6 times the size of Earth in diameter (86,881 miles), making it 1,322 times the size of earth in volume, you could fit over a thousand earth's inside Jupiter. Being so massive has made Jupiter a solar system within our solar system, as it's extreme gravitational pull captures lots of objects as moons of Jupiter.

Jupiter's size compared to earth, the entirety of earth could fit, with room to spare, in Jupiter's 'great red spot' (an acid hurricane that has been raging on Jupiter for centuries)

Jupiter currently has 79 known moons. This number keeps increasing as recently as July of 2018, we added 10 newly discovered moons to the total. 26 of the moons are so new they are still awaiting official names. We are not done adding to the number of known moons of Jupiter. Astronomers are discovering new moons of Jupiter so frequently the main trick has become making sure the newly observed moons are not the same as a moon we have previously counted.

The number of moons of Jupiter will also be changing further as new moons are likely about to be made and destroyed. Of the known objects going around Jupiter most are going the same direction but, some are going the opposite direction and just like if you go the opposite direction of traffic in a traffic circle collision is likely.

If you look at Jupiter with even just a halfway decent pair of binoculars you will be able to see 4 of Jupiter's moons Io, Europa, Ganymede, and Callisto. These are called the Galilean Moons as they were first observed by Galileo in his small telescope. They are very easy to make out even in small telescopes/binoculars but, telling which one is which takes several observations over a long period of time as they are circling Jupiter and you can only see this movement edge on from Earth. To determine a moon’s true distance from Jupiter you must watch the moons to see when they stop getting further from Jupiter, turn around and get closer. (or you can just cheat and use this web tool)

how Jupiter and it's 4 Galilean Moons appear in a telescope or binoculars (the stripes/spot can be much harder to see than it might look from this picture)to

All of the Galilean Moons are interesting places and studied extensively. Io (the closest) is the most volcanic body in our solar system, Eropa is the smoothest body in our solar system it’s believed to have liquid water and therefore possibly life beneath it’s ice surface. Ganymede is bigger than the planet Mercury, and Callisto (the furthest out) is the most cratered body in our solar system.

Jupiter’s moons served as one of the first standardized clocks. Jupiter’s moons movement is regular and predictable so the Royal Observatory in Greenwich calculated and published their future locations and local time (as would be shown on a sundial or pendulum clock) at Greenwich, forming the foundations for our time zones based around Greenwich Mean Time.

With a good pair of binoculars you can also see red stripes contrasted with white stripes this is Jupiter’s atmosphere. The change in coloration is caused by different compounds in the atmosphere that change color when exposed to the light of the Sun.

A really good set of binoculars or a decent telescope you can see the red spot which is an acid hurricane more than twice the size of earth that has been observed since at least 350 years ago. This has been the only silver lining of stargazing in Colorado thru the smog/haze from the wild fires in the mountains is that the haze has been increasing the contrast on Jupiter making the stripes and spot easier to see (I've actually been able to make out a personal record number of stripes this year seeing 7). A day on Jupiter last about 10 hrs so over the course of a long winter night you can watch Jupiter do a full rotation by watching the great red spot do a lap around the planet.

close up of the spot on Jupiter

Jupiter is currently “in Capricorn ”. Capricorn doesn't look like much unless you have really dark sky, but you will see Sagittarius to the right, right next to it! If you have decently dark skies and some imagination you might see a constellation that resembles a teapot just to the right of Jupiter. A triangular lid atop a trapezoidal body with a trapezoidal handle on the east side and a triangular spout on the west side. Even better if you are in a particularly dark area you can see the milky way appearing as steam coming out of the spout. This “teapot” was originally seen as an archer, and named Sagittarius. The tip of the spout to the two stars that make the top of the handle are the arrow and the top of the lid and the two stars to the right of the base make the bow for the archer.

The archer's arrow is drawn pointing to the west towards a bright star with a red/orange hue. This star is Antares. Antares is not to be confused with mars which is currently rising in the eastern sky around 10pm ~ish (this is such a common mistake it is where Antares name came from, it's Arabic for 'rival of mars'). The star Antares is the heart of the scorpion or Scorpio. and Sagittarius is protecting others from Scorpio by keeping his bow drawn towards it's heart.

Capricorn, Sagittarius, and Scorpio you might be familiar with from the zodiac over the course of 12 years we can watch Jupiter move across every sign in the zodiac. If you read my post on Jupiter two years ago you have been able to watch Jupiter move from the constellation Scorpio to the next constellation in the zodiac Sagittarius and now to Capricorn! Jupiter takes just a little less than 12 years to go around the Sun, there are 12 signs in the zodiac, therefore Jupiter spends a year in each one! so next year we can be sure to find Jupiter in Aquarius!

Come get a closer look at Jupiter seeing it's stripes (this year better than ever with the haze), moons, red spot and more! On an astronomy tour! Book now for an out of this world experience!

The word disaster comes from Greek meaning “Bad star” deriving from the astrology interpretation that catastrophes are caused by the position of the planets. Given the current pandemic making most of the world distance from each other let’s take a step back and look at how bad this ‘star’ really is.

I have thought up a scale to rank disasters and it starts at the Zeroth Degree and getting progressively worse till the Fifth Degree. In this system I would only rank COVID-19 as only maybe a ~0.7 there’s a lot that could be far worse.

Starting with Zeroth Degree, any disaster which causes minor to significant hassle would be in the 0th Degree. This is sort of a bottom end catch all for everything from this current pandemic to burning your dinner. Anything that might make a major impact on civilization but not enough to wipe it out. That’s why I give COVID a .7 it’s definitely worse than a day to day disaster, and being global it ranks higher and localized disasters like volcanoes. However all told COVID might make even a huge impact on civilization but not change our dominance on earth.

NOAA-19 satellite - The satellite fell while it was being worked on by Lockheed Martin Repairs to the satellite cost $135 million.

Making a First degree disaster of course something that threatens human civilization. Humans might continue to live in small pockets and maybe repopulate or be around to see what lifeforms take over earth next but either way we would no longer be the obvious dominant life form on earth. This would be something like an all out nuclear war, depletion of resources, or alien invasion.

passed extinction events - blue bars show the percentage of marine animals apearing to become extinct during given time interval, peaks are evidance of "mass extinction" events.

A Second degree disaster is something that wipes out all human life, but not all life. A scenario where only the hardiest of microbes or the deepest of sea creatures survive. Something like the loss of our atmosphere, meteor strike, or a chain of catastrophic tectonic activity.

The Third would obliterate all life on earth and therefore all known life maybe the sun flares up and boils the oceans off or the earth gets knocked off course and sent out of the solar system to freeze.

The Fourth Degree is where we really start to see some damage. This is where the entire solar system is destroyed there is no hope that any record of humanity or earth survives. This would be where the sun explodes, or we drift too close to a black hole.

The sun expanding to engulf the earth 1AU = the distance to the sun from the earth right now.

Lastly leaving the Fifth Degree one in which the entire universe is destroyed, something fundamental in the laws of physics that lead to a universe where life as we know it is impossible.

The "big crunch" one of the proposed fates of our universe.

Hopefully this helps make the outbreak seem mundane and unremarkable by comparison. For the next few weeks I plan on going down each degree of destruction and talk about how likely it is and what hope if any we have to prevent them. So I’ll see you next week with the maximum destruction, the 5th degree!

  • Luke

My last blog post went over the history of how our current model of the universe came to be. This is not the end of the story by far. We will forever be in this story as it's hard to see our understanding of the universe will ever being complete. I’d also suppose that there are many commonly held beliefs today that are just as wrong as the earth being in the center of the solar system.

Artist's logarithmic scale conception of the observable universe with the Solar System at the center, inner and outer planets, Kuiper belt, Oort cloud, Alpha Centauri, Perseus Arm, Milky Way galaxy, Andromeda galaxy, nearby galaxies, Cosmic Web, Cosmic microwave radiation and Big Bang's invisible plasma on the edge.

I mentioned the observable universe at the very end of my last post. Observable universe is to say we limit our universe down to just what we can see. The basic idea is that if the universe is ~13.8 billion years old, and nothing moves faster than the speed of light, we should only be able to see things that are ~13.8 billion light years away (the distance light travels in a year).

It’s a little more complex the observable universe actually has a radius of ~46 billion light years. This is larger than the what we would expect knowing age of the universe because the universe is also expanding. How I like to think of this is say you are baking bread with raisins in it, when you put the dough in the oven you have raisins spaced out 1cm from each other. If you pick any one raisin you will have the closest raisin is 1 cm away, next one is 2 cm away, next is 3 cm, and so on. Now when you bake the bread it doubles in size so now the closest one is 2 cm away the next one is 4 cm away, next is now 6 cm away, and so on.

As the universe expands things that are farther away move farther away faster. in this picture one raisin is 5cm the other 10cm when baked the bread becomes twice as big moving the near raisin 5cm (to 10cm away) while moving the far raisin 10 cm (to 20cm away) over the same amount of time. The raisins represent galaxies.

We can see ~46 billion light years in every direction because when that light left the most distant objects they were only ~13.8 billion light years away. This gives us a limit to the universe, a horizon ~46 billion light years away (a sphere with a radius of ~46 billion light years). We’ve been able to map this horizon and call it the “Cosmic Microwave Background Radiation”

The Cosmic Microwave Background Radiation (or CMB) is the first light that was able to be released during the big bang. The CMB was discovered by Arno Penzias and Robert Wilson in the 1960s. While working at Bell labs Penzias and Wilson, had noise coming in from a large horn shaped antenna no matter where they pointed it, they evicted some pigeons that were nesting in the antenna, and still had the noise. They determined that the radio signals they were picking up had to be from outside the galaxy but didn’t have an idea of what it could be. Later Penzias heard of the work of Robert H. Dicke who had predicted the CMB and realized it matched the noise he was picking up in his antenna. If you ever pick up static or noise in a radio receiver a small part of it is the background noise is the CMB.

WMAP (Wilkinson Microwave Anisotropy Probe) image of the CMB (Cosmic microwave background radiation). This is a 2D projection of a sphere just like a world map you can imagine this as a globe with the earth as the smallest speck in the core.

I’ve always found it interesting that we started with the ancient Greeks thinking the stars were just on a sphere that was centered on the earth, and today’s understanding has us in the center a much larger sphere called the CMB. This is the edge of the observable universe which makes it always centered on the observer. If we were Observing from Saturn it would be a sphere with Saturn in the center, if we went to a different planet around a different star in a different a galaxy it would still just be a sphere surrounding us. Even you have a different observable universe centered around you that no one else can observe.

There’s no way to see passed this sphere but there’s nothing that would indicate that the universe is somehow different outside of what we can observe. No one thinks of this sphere in the same way the early astronomers thought of the sphere of the stars was the limit of the universe, but the similarity in their geometry is an odd coincidence.

There’s many things we know we don’t understand: dark energy, dark matter, dark flow, or dark fluid. All of these “dark” things describe different phenomenon that we can see the effects off but don’t know the source

I will save talking about each of these in detail for a later post but since I touched on the universe expanding this brings up “dark energy” nicely.

The universe is actually expanding faster and faster (accelerating). You would think gravity which pulls all things together would be slowing the expansion but our observations tell us the expansion is accelerating. For the expansion to over come gravity and to accelerate it needs to be getting energy from somewhere. Dark energy is the unknown energy source that is expanding our universe. If you think back to the raisin bread analogy, dark energy is like the yeast that makes the bubbles that ultimately makes the bread expand.

To accelerate the expansion of our universe at the rate it is there must be a lot of Dark Energy. So much that it's thought to be the majority of what our universe is made of!

Our models of the universe are still limited by our technology and what we can see from where we are in the universe. If you look at a map of all the known galaxies you will notice it’s hourglass shaped, and the bottom is a little more sparse than the top.

The hourglass shape is because we are viewing the universe from within the milky way. It’s kind of like if you think about looking at the world being in the middle of a sheet of glass you can see up and down very well but looking edge on everything is obscure and distorted. Looking edge on in our milky way there’s many stars but if you look at any directions away from the plane of our galaxy we see fewer. If we want to look at other galaxies the best way to do so is in the directions where there’s less nearby stars to get in the way.

There's nothing to indicate the dark areas are different than what we can see. No one thinks this shape represents how our universe looks. The hourglass shape just shows off our cosmic blind zones. This is similar to how we assume what's outside of the CMB horizon is the same as what we can see within it.

Our galaxy like this lends lets us look thru the thin axis easily but it's hard to see anything looking through it edge on.

Why there’s so many more in the top part of the hour glass than the bottom is due to the geography of earth. There’s more land, people, and resources in the northern hemisphere that the sky above North America, Asia, northern Africa and Europe is much better cataloged than the sky above South America, southern Africa, Australia, and Antarctica. All of these factors: only being able to see the observable universe, the vast dark holes in our understanding of our universe, and the limitations in our current technology give us our current understanding of the universe. There are many things waiting to be discovered. I feel everyone has something to add to this story, aiding in development of our understanding of the universe.