Live Q&A: Pluto's Identity and the Fate of our Universe!

WE’RE LIVE! Welcome to our first ever live episode notes! (We had a blast)

News:

4G Mobile Coverage on the Moon!

Thanks to European mobile operator Vodafone, eqiptment from Nokia, and lunar rovers from Audi, a 2019 mission is slated to launch a SpaceX Falcon 9 rocket, bringing two lunar landers to the surface of the Moon. Along with them, they will establish 4g Mobile Coverage so the Audi rovers can communicate with eachother and send home the first ever HD video feed from the surface of the Moon.

Enhancing Human Potential

Background: Once a human ventures beyond Earth’s magnetic field, we become vulnerable to cosmic rays that are well, deadly..Causing things like cataracts, circulartory disease, damage to your central nervous system and fatal cancer. This is why getting to Mars, Enceladus (saturns moon, beneath its ice shell is a liquid ocean), and Titan is too dangerous to even consider at this point. However, a group of biologists and NASA’s Ames Research Center have begun researching ways to raise the radioresistance of humans. This is currently a characteristic of tartigrades, microscopic water bears that have survives every mass extinction on Earth.

Live Questions from Audience:

Q1: What happened to Pluto? (Chloe from Aliso Viejo)

In August 2006, The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. So, the three criteria of the IAU for a full-sized planet are:
1. It is in orbit around the Sun.
2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
3. It has "cleared the neighborhood" around its orbit.

Essentially Pluto meets all the criteria except one- it “has not cleared its neighboring region of other objects.” You may wonder what that means, “not clearing its neighboring region of other objects?”  This means that the planet has become gravitationally dominant -- there are no other bodies of comparable size other than its own moons, in its vicinity in space.

Q2: Why is Space Black? (Jenna from Laguna Niguel)

If the the sky is full of stars, why don’t we see a bright sky?

The thing we have to realize is that our universe is only 13.8 billion years old. That means we can only see objects as far away as the distance light can travel in 13.8 billion years. The light from stars further away just hasn't reached us yet.

Another reason that the sky may not be bright is that the far ones are moving further away from you, causing it to become redshifted, lengthening the wavelength even further. Just like getting sucked into black hole, the light may shift so far to the red end of the spectrum that it is no longer visible at all to humans. 

Q3: How fast is it expanding?

The universe is expanding in all directions! No, this does not mean we are the center, but every galaxy is moving away from every galaxy at different rates. Scientists estimate that objects 1 megaparsec apart (or 3.3 million light years, almost 2 quintillion miles (18 zeros)) are moving away from each other at 68 km/s or 42 mi/s.  Similar to the last question, we find that objects further away from us are moving away faster, with light shifted further to red end of the spectrum, meaning objects closer than one megaparsec and moving away at a slower rate.

Q4: Does the first country to the moon claim it as their own?

While Russia launched Sputnik first into space, and Neil Armstrong first walked on the Moon and planted the American flag, no country can hold claim because of the 1967 Outer Space Treaty.

129 countries, including China, Russia, the UK and the US, have committed to this treaty, which "sets out important principles, such as the concept that space should be considered the province of all mankind, that outer space is free for the exploration and use by all states, and that the Moon and other celestial bodies cannot be claimed by a sovereign nation state. Additionally, the Moon and celestial bodies are to be used purely for peaceful purposes, and weapons will not be placed in orbit or in space."

Q5: What is space made of?

Disclaimer, we can tell you more about what we don’t know, than what we know:

Currently estimate:
68% Dark Energy
27% Dark Matter
5% Normal Visible Matter

Dark Energy is the thing we don’t know much about. We named it dark only because we don't know much about it, not because it's too dark to see. All we know is that is behaves as energy and aids in the universe’s expansion. Einstein predicted that even empty space has this energy, that it is embedded in the fabric of space.

Dark Matter, we only know to exist based on it’s gravitational effects. For instance, due to the laws of planetary motion, we know that the further away a planet’s orbit, the slower its speed. That should be true with Galaxies as well but it’s not. Besides a very small portion around the central black hole, the orbital speed near the center of the galaxy is almost equal to the orbital speed at the edge. The problem is that there isn’t enough matter in our galaxy to produce the gravity necessary for this to happen, so we have coined the phenomenon, Dark Matter. Dark, because we don’t know much about it, and we can’t see it!

Now when you look into the black of space, you’re looking at what scientists call the Interstellar Medium. It is so dilute though, that it only contains 1 molecule per cubic centimeter. Our own atmosphere on Earth has a density of about 30 Quintillion molecules per cubic centimeter. When scientists have observed it, they have found the interstellar medium to consist of 90% Hydrogen, 9% Helium, and 1% of all the other elements blasted of into space by the death of massive stars and the big bang.

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Tony DiBernardo

Founder | Space, But Messier!