Mass Extinction, Soon?

It’s no secret that that an asteroid impact 65 million years ago caused a chain of environmental disasters. Countless species were driven to extinction, evaporated by the impact, suffocated by volcanic ash, eradicated by the rapid climate change. It’s unlikely that we’ll ever have the technology to predict when the next extinction event will happen. Does that mean that humans will just have to deal with the aftermath, if it happens in our species’ lifetime? Or is there a way to create a “back-up drive”, so to speak?

This is one of the biggest reasons why the space industry is so motivated to get us to Mars. In our current generation, we’d like to just explore it, learn more about it, do research on how it was formed and why it turned out to be the way that it is. Even if the idea of colonizing Mars is far, far, far into the future and not feasible within the next few generations, it’s a start. Instead of piling all of our valuable eggs – the human species, our technological advancements, our understanding of physics and the universe – into one basket, we’ll be working our way towards a second basket. So if some sort of mass extinction event were to occur, such as a devastating volcanic eruption or another enormous asteroid impact, we would have a back-up of all of the knowledge and technology that we have here on Earth. We would be set behind significantly in terms of advancement and progress, but we wouldn’t lose everything.

 

 

Life in Our Solar System

One of the biggest questions that philosophers and scientists alike ask: Are we alone in the universe? Is it possible that there’s sentient life outside of our small blue planet? The Fermi Paradox asks us this question. The universe is so big. Using even the most conservative estimations of exoplanets in the habitable zone, calculations show that there millions and millions of Earth-like planets in our galaxy alone. So where is everyone?

Scientists hoped to find evidence of water and other habitable regions on celestial objects within our solar system. It’s theorized that there was once liquid water on Mars’ surface, or that tiny bacteria could survive in Europa’s icy underwater oceans. But what would this mean for us, if we did find evidence of life on these nearby planets and moons?

The implications wouldn’t be good. The idea of a Great Filter explains why we haven’t seen any evidence from other galactic civilizations. In other words, it should be hard for sentient life to evolve. Given that our solar system is a tiny, tiny fraction of the entire universe, finding evidence of life right here in our own backyard implies that life is easy to come across.

This contradicts the Fermi Paradox above! But there’s alternative explanation that satisfies the Paradox: It is easy for life to evolve… but it’s difficult for life to sustain. If it’s easy for life to evolve, but we haven’t heard anything from large civilizations, it’s reasonable to assume that the Great Filter is ahead of us. Humanity will have to make some sort of evolutionary leap in order to ensure our survival into the far future.

So all in all, it would probably be bad news if we were to ever find life on Mars, Europa, Titan, etc. Here’s to hoping that all planets we come across are a barren wasteland!

Footprints on the Moon

Going to the moon – a feat that was never even dreamed by our ancestors. It seems unthinkable. Being able to go to something so far away. Being able to survive the harshness of space, even just momentarily inside a puffy marshmallow suit. It was unthinkable, a few centuries ago. But now we have evidence: the infamous footprints on the moon. And the best part? That evidence is unlikely to go away. In fact, it’s likely that those footprints will still be there as the moon is destroyed by our ever-growing sun.

But how is it possible for such small footprints to survive millions and millions of years? Unlike on Earth, there is no atmosphere, the minuscule amount of water is frozen solid, and there’s no volcanic activity to re-mould the surface. There’s no wind. Nothing gets washed away. Nothing gets folded back inside. It’s a startling type of permanence that we don’t have here on our own planet.

But there’s is a possibility that these footprints will be wiped clean. Also unlike Earth, our moon has no atmosphere, no magnetic field, nothing to protect it from incoming bombardments of meteors. A single large meteor could single-handedly erase the evidence. Over time, small micrometeorites that are estimated to impact at more than 33,000 mph will slowly erode the surface. But this process is slow, and with each passing day, the sun uses up more of its fuel and progresses further along the main sequence. Humans have made a mark on the moon, and that mark is there to stay for a very, very long time.

Walking on Diamonds

At some point in their life, every girl (or guy, I’m not judging!) wants a beautiful diamond on her finger. Not only are they shiny, sparkly, and oh-so-shimmery, but also incredibly expensive and valuable – from a material’s standpoint.

But out there, floating out in the depths of the universe, exists a planet created with diamonds. 55 Cancri e is an exoplanet 40 lightyears away, roughly 10 times the mass of Earth, but only twice as large. It orbits its host star with a staggeringly low period of just 18 hours, and is close enough and hot enough to where the surface can melt iron.

Initially believed to be another water planet, 55 Cancri e was watched carefully and measurements were taken to confirm its composition and density. However, initial observations showed no traces of hydrogen in its Lyman-alpha signature. New speculations regarding its composition arose, and the idea of a Carbon dominated planet gained popularity. Given the intense heat and pressure from its host star and the internal pressures from its core, it’s likely that any carbon inside the planet has taken the molecular form of diamond.

So to answer the statement in the title, you wouldn’t be able to walk on diamonds from this planet… you’d burn alive before you even got close to it! But perhaps, one day in the future, the ability to harvest such resources will be available. The ability to harvest precious jewelry, and the ability to harvest other potential life-enhancing resources.

Venus – Is it Habitable?

When you think about humans moving to other planets, your train of thought probably leads you to think about Mars. Sending spacecrafts to Mars, talks of terraforming Mars, the works.

But another planet that has been a subject of many science fiction stories is none other than Earth’s sister planet: Venus.

Venus’ surface is hostile. So far, we’ve sent more than 20 successful space missions to observe the planet. But because the atmospheric pressure at the surface is over 90 times that of Earth’s, only a few spacecrafts managed to reach the surface. Even then, they survived only an hour before collapsing.

Not only that, the temperature at the equator reaches as high as 500° Celsius – higher than the melting point of lead. This is one of the significant reasons why water is not just scarce, but completely absent in any form.

Despite all of this, there are ideas of colonizing Venus’ atmosphere. One of the main proposals is using a breathable air (a nitrogen / oxygen solution) as a lifting gas. Nitrogen and Oxygen have less density than the lower atmosphere of dense carbon dioxide and sulfuric acid, but not so light such that it escapes Venus’ atmosphere entirely. Calculations show that the breathable, air-filled balloons would hover around a height of 50 kilometers, where the temperature averages around 75° C / 167° F. If there was a way to further decrease density so the balloons hover a mere 5 km higher, the temperatures would further decrease to 27° C / 81° F.

SpaceX has officially created a non-zero chance of a car accident in space.

February 6, 2018.

The Falcon Heavy launched into space with Elon Musk’s own personal Tesla Roadster.

SpaceX has had many successful launches, had several successful landings, and on top of all of that… they can claim themselves to be the first ever company to send a car to space.

 

Yes, that’s a real image. No, it is not photoshoped.

So for the uninitiated, what made this launch so incredible? For starters, the Falcon Heavy has a maximum payload of 63,800 kg (almost 150,000 lb), clocking in as one of the highest capacity rockets ever build in all of history. To be more precise, it’s currently sitting at number 4, right behind Saturn V, Energia and N1.

But the real kicker is: the Falcon Heavy has twice the payload capacity compared to the Delta IV Heavy (one of the few other operational vehicles) at one-third the cost.

Purely by itself, that doesn’t sound too impressive. But once you actually start adding in numbers, that statement becomes pretty freaking mind-boggling. The Delta IV was an incredible invention itself, but it costs almost $435 million dollars to launch.

Falcon Heavy?

$90 million.

And don’t forget, the Falcon Heavy is currently ranked number 4 in the history of all of mankind in terms of high-capacity rockets!

Why Christopher Nolan’s tidal representation in Interstellar makes a terrifying sort of sense.

Note: Spoiler alert for those that haven’t seen the movie!

 

 

Within the Interstellar universe, there exists an enormous black hole in a distant galaxy, named Gargantua by the movie’s characters. Around this black hole orbits several different planets, and the characters are hoping to explore and learn more about them. One of these planets, known as Miller’s Planet, orbits closely around this black hole to the point where the spacetime is warped heavily. A single hour on Miller’s Planet is equal roughly 7 years of Earth time.

Those are scary numbers. Really scary.

But in my opinion, there’s an equally scary implication because of this warped time frame, albeit much more subtle.

As we’ve learned in class, high tides and low tides are caused by the gravitational pull of objects rotating around each other. Earth has 2 major sources that pull on its tides: the sun and the moon. As Earth rotates, any single point on Earth effectively “passes through” the tidal bulges twice in a single rotation of the planet.

 

 

Similarly, in the movie, Miller’s Planet has a single source of enormous gravity: the black hole, Gargantua. Not only does the close proximity to the black hole cause an extreme warping of spacetime… but it also results in a very strong gravitational pull on its tides.

 

 

That gravity pulls nearly all of the water on the planet into two enormous bulges, and those bulges are the “high tide” of the planet. Every time the planet spins on its axis, any one point on the planet’s surface experiences those high tides twice.

And the remember the scary thing that I mentioned earlier?

Miller, the person the planet was named after, had been broadcasting from the planet for the entirety of the characters’ journey – roughly 10 years. Everyone thought she was alive. However, when the characters arrived on the surface of the planet, it was very clear that she had died. All of her equipment was broken and in shambles.

Remember, on this planet, 1 hour = 7 years.

In the scene, you can see a tidal wave receding into the horizon, right as the second tidal wave comes into view from the opposite direction. Miller had only been broadcasting for 10 years. If we do the math, it is very likely that Miller was killed in the tidal wave that we see receding.

She had probably only died a few minutes before the characters arrived at the planet.

Historical Astronomers in Context

Johannes Kepler’s (December 27, 1571 – November 15, 1630) primary contribution to the astronomy field was his laws of planetary motion. Not only are these concepts important to modern day astrophysics (such as when sending satellites to study distant planets), but also lay the foundation for Newton’s work on universal gravitation.

One major astronomical event that happened during Kepler’s lifetime was the Supernova of 1604. It was a supernova that occurred in our galaxy, and was bright enough to be observed with the naked eye. In fact, it is the most recent supernova to have been bright enough for that to happen.

Another major historical event during Kepler’s lifetime was the establishment of Jamestown. Founded in 1607, Jamestown was the first permanent English settlement on the North American continent and was the beginning of American history.

An important figure during the 17th century was Queen Elizabeth I (born 1533 – death 1603). She established the Church of England, allowing Roman Catholicism and Protestantism to exist together. Not only that, she was one of the longest ruling monarchs in all of English history, and through the victory against the Spanish in 1588, established England as one of the most powerful nations in the world at the time.

I thought that it was interesting how many major events happened during this era. Within a century, you have the the foundation for major laws of physics, the defeat of the Spanish Armada, the rise of the English empire, the start of American history, and the brightest supernova for the next few hundred years. Similarly, you can look at modern history and you can see things like the numerous wars, the advancements in technology, all of the discoveries made in the past century. Rarely do people actually stop to think about how many of our actions are written down in history, and how often those things happen.

The Universe in Dots

Let’s say the average human has a lifespan of 80 years. To make it a little easier on our calculations, we’ll bump it up to 100 years. Let’s represent that as a dot.

The species Homo Sapiens has been around for roughly 200,000 years. If the human lifespan is shown as a single dot, the age of mankind would be 2,000 dots.

Dinosaurs walked the Earth until 65 million years ago, when they were quite rudely wiped out by a giant flying rock and the catastrophic environmental disasters that ensued. Things didn’t start settling back down for another few million years, and we enter the Eocene era about 50 million years ago. That’s 500,000 dots.

If I were to keep going with the age of the universe, you’d quickly run out of bandwidth. So let’s take a break here and scale down our dot size. One red dot = 500,000 black dots.

The age of Earth itself is dated to approximately 4.5 billion years old. That means that of Earth’s lifetime, humans have only been around for about 0.004% of that time. If we were to use the dot representation, we would have to use 45 million / 500,000 = 90 red dots.

The age of the universe is estimated to be about 13.82 billion years. 13.82 billion / 500,000 is roughly 140 red dots.

Remember, each red dot is a really, really big block of black dots.

It’s easy to forget just how mind-blowingly large a “billion” really is. Pictured above, those 140 red dots don’t seem like very much, but once you realize that each of those red dots represents one of these…

…you start realizing just how much meaning is packed into the phrase, “13.82 billion”.

The Cosmic Calendar is a long calendar, and the human lifespan is just a blink of an eye when you compare it to the lifetime of the universe. But I think it’s also important to remember that we are an incredible species. Thousands of years ago, humans never would have dreamed of flying across the big blue sky. A few decades ago, humans never would have dreamed of traveling to the moon. Right now, we can’t even dream about floating amongst the stars. But maybe, one day we will.

As Carl Sagan said,

“We are a way, for the cosmos, to know itself.”

Thanks for reading,

Emily

Saying Hello

Quick introduction for Blog 0: My name is Emily Dong. I’m a sophomore at Vanderbilt University majoring in Computer Engineering and minoring in Astronomy. I’ve been interested in astronomy for a while now, as seen in the (very dark) picture above of a night-time astronomy lab.

One of my favorite blogs: Wait but Why. The author has some great articles that really fueled my interest for astronomy, and I still re-read them to this day.