This is the Milky Way galaxy.
Home to planet Earth.
The Milky Way is part of a large group of galaxies known as the Local Group consisting
of more than 54 gravitationally bound members.
Most of them are quite small with the exception of Andromeda, the Milky Way, and Triangulum.
A few billion years into the future, these larger members will collide and eventually
form a much larger galaxy nicknamed Milkdromeda. I know, very original...
Now, lets go much further into the future, about 100 billion years from now.
Imagine that somewhere within Milkdromeda, a habitable planet gives rise to a civilization
of intelligent beings much like ourselves.
At some point they invent a powerful new telescope
which will allow them to explore space beyond the galaxy.
But as they peek trough the telescope, they find nothing.
Nothing but darkness and empty space.
They come to understand that they exist within a seemingly endless and almost informationless void.
Milkdromeda would appear to be a bastion of light in a sea of darkness.
It may sound like science fiction but it's actually a very plausible future.
As the age of the cosmos approach 100 billion, the expansion of the universe will cause all
other galaxies to vanish beyond the cosmic light horizon.
This means that light from other galaxies will no longer be able to reach us.
Put another way, galaxies will be pushed outside of the
observable universe and can thus no longer be observed.
Everything outside of the Milkdromeda galaxy will be virtually erased from existence.
Just like observers in other galaxies will experience the exact same phenomenon.
If you think about it, we are rather fortunate to exist at a point in time when we have access
to such an abundance of information.
Sure, there are a lot of things about the universe that we do not understand but at
least there's hope that, one day, we will.
The distant future of 100,000,000,000 CE however, would be so information-deprived that when
they aim their equivalent of the Hubble telescope towards a seemingly empty region of space,
the returned image would also be empty.
And even though many questions could still be answered by studying other phenomena, like
hypervelocity stars and cosmic microwave background, so much of the universe
would be out of reach and, consequently, unknowable.
Of course, the same is true today.
We have no way of knowing what lies beyond the observable universe.
So just as we imagine our populated bubble to be a reflection of what
lies beyond, intelligent inhabitants of an isolated Milkdromeda may do the same.
On September 7th, 2016, Earth had a very close call with an asteroid known as 2016 RB1.
The asteroid was between 7-16 meters in diameter and flew
past the Earth above the South Pole at an altitude of 34,000 km.
To give you an idea of how close that truly is, many communications and weather satellites
orbit the Earth at an altitude of 42,000 km.
In other words, it was so close that it flew in between the Earth and our satellites.
But like most asteroids, 2016 RB1 also suck at this astronomical
game of Darts and missed the board entirely.
But even if it had scored a Bullseye, the damages would likely have been minor.
As some of you might remember, back in 2013, an asteroid struck the Earth
above Russia and caused damages to various buildings and windows.
That asteroid/meteor was not only larger at 20 meters wide
but also had a greater impact velocity.
So 2016 RB1 would, at most, have cause minor damages to buildings and windows.
However, it is a bit disconcerting that the asteroid was
only detected 24 hours prior to it's closest approach.
If a future asteroid or comet should pose a threat to the Earth, the glow of the meteor
itself may be our first and final warning.
In 1997 the very first commercial was filmed in space aboard the Russian space station Mir.
A prominent advertisement agency filmed the commercial for an Israeli diary company and
features a cosmonaut aboard the station drinking the company's milk.
In 2001, the American fast food chain Pizza Hut sent a vacuum-sealed pizza to the astronauts
and cosmonauts aboard the ISS as a commercial stunt.
However, something far more interesting happened back in 1993.
A company known as Space Marketing, Inc. announced that they
would launch a giant billboard into low-Earth orbit.
The 1 km² billboard would have been made out of a lightweight polyester film and if it
had been launched it would've appeared to be as large and bright as the Moon.
The project never progressed due to concerns about
space debris and an inability to attract adequate funding.
But more importantly, it was faced by immense opposition from
both the public and the scientific community.
Which is completely understandable as no one wants to have their sunset or astronomical
observations interrupted by a giant floating Coca-Cola sign.
See, the guy in this stock footage couldn't even handle the mere prospect.
People where so opposed to the project that a bill
was later introduced to ban all obtrusive advertising in space.
And for some inexplicable reason. Someone even took the legislation and made it into a flash game.
But..
Why?
US based companies has since been prohibited by law from launching any giant billboards
into space but, then again, the ESA, Russia, China, or anyone else could still do so if they wanted to.
This is the Crab Nebula.
It's a stellar remnant of a star that went supernova in 1054 CE.
Well, the star actually went supernova about 6,500 years before that but the light from
the explosion reached the Earth in 1054 CE.
We know this, in part, thanks to historical records describing the observations of the event.
Here's a quote from an ancient Chinese text:
"I humbly observe that a guest star has appeared; above the star there is a feeble yellow glimmer."
The term "guest star" was used to describe a star that had suddenly appeared before disappearing again.
Of course, we now know the light they observed was that of a distant supernova.
The explosion of the star, located 6,500 ly away, was so bright that it remained visible
for almost two years and even remained visible during the day for the first month of its appearance.
And this is not an isolated incident as quite a few
supernovae have been observed and recorded throughout history.
The first supernova for which records exist is believed to have occurred in 185 CE.
Chinese astronomers of the time wrote:
"A strange star appeared in the middle of Nan Mun, It was like a large bamboo mat."
"It displayed the five colors, both pleasing and otherwise. It gradually lessened."
"In the 6th moon of the succeeding year it disappeared."
The brightest supernova in recorded history was observed in 1006 CE.
Even though the explosion occurred 7,200 ly away it was bright enough to cast noticeable
shadows on the ground and even allowed people to see in the dark of night.
On June 4, 1974, NASA began construction of the very first orbiter of the new Space Shuttle program.
The orbiter carried the designation OV-101 but was later planned to be named Constitution.
However, after NASA received hundreds of thousands of letters from avid fans of the TV-show Star Trek
requesting the Space Shuttle to be named Enterprise, NASA officials decided to seek
the President's approval for the name-change.
Declassified White House documents reveal that President Gerald Ford approved the renaming
of the Space Shuttle for this exact reason and one of his advisors wrote:
"It seems to me 'Enterprise' is an excellent name for the space shuttle."
"It would be personally gratifying to several million followers of the television show 'Star Trek',"
"one of the most dedicated constituencies in the country."
The term Space Shuttle was likely inspired by Star Trek as well.
Prior to the 1960s the title Integrated Launch and Reentry Vehicle, or ILRV, was used to
describe a vehicle for traveling between a planet's surface and space.
However, soon after the Shuttlecraft was introduced in Star Trek, NASA officials began using the
term Space Shuttle to describe such a vehicle.
In any case, in recognition of it's fictional namesake, both the original cast and creator
of Star Trek where invited to attend the dedication ceremony of Space Shuttle Enterprise.
Inside the Eagle Nebula, some 7,000 ly from Earth,
there's a beautiful region known as the Pillars of Creation.
But some astronomers believe that the formation has already been destroyed after a nearby
star went supernova some 9,000 years ago.
So the light from the supernova has already reached the Earth but as the shock-wave is
much slower than the speed of light it only reached and destroyed the Pillars of Creation 6,000 years ago.
And as the nebula is 7,000 ly away, it will be another millennium until the light
from the formations destruction reaches the Earth.
In November of 1969, the crew of Apollo 12 safely landed on the Moon and soon experienced
what it was like to walk around on the Lunar surface.
As the two astronauts conducted their extravehicular activities they followed the instructions
printed on the flip book attached to the wrist of the spacesuit.
Take some measurements, set up equipment, collect some rocks, Playboy magazine...
Playboy magazine?
This is actually what Pete Conrad and Alan Bean saw on their first EVA on the Moon.
They both explained in a 1994 interview that:
"It was about two and a half hours into the EVA, I flipped the page over and there she was."
"I hopped over to where Pete was and showed him mine, and he showed me his."
They revealed that the photos had been added as a joke by the backup crew without anyone's knowledge.
One of the models featured in the flip book is even visible in a photo released by NASA to the public.
In 1910, the Earth passed through the tail of a comet known as Halley's comet.
As astronomers examined the tail of the comet
prior to the fly-by they detected a poisonous gas, known as cyanogen.
The gas posed no threat to the Earth as it was far too rarefied but when they announced
their discovery, the public could only focus on one aspect.
Quite a few people panicked and began to prepare for the incoming attack.
Some purchased gas masks while others capitalized
on the hysteria by selling so called "comet pills" to the less informed.
And in a few extreme cases, people actually committed suicide as they believed the comet
to be a sign of the end of the world.
I even found an article of a man who crucified himself.
But on May 18th, Earth passed through the tail of the comet and absolutely nothing happened.
In August of 2016 astronomers discovered an exoplanet orbiting Proxima Centuari.
At a distance of 4.2 ly it is the closest star to the sun which makes the planet,
Proxima Centuari b, the nearest exoplanet to the Earth.
What's even more exciting is that the planet is within the stars habitable zone which could
allow for liquid water on its surface.
However, much, much more information is needed
for a proper evaluation of its potential for both life and habitability.
But it's exciting nonetheless!
If the planet should turn out to be habitable, it could become a serious candidate for human
colonization at some point in the distant, distant future.
Because, well, space and human lifespans go together about as well as Valve and the number 3.
However, a project known as Breakthrough Starshot is aiming to send a fleet of tiny automated
probes that will travel at 20% the speed of light and thus reach Proxima Centuari in only 20 years time.
A trip that would otherwise take tens of thousands of years using conventional rockets.
And once the probes reach their destination it would only take 4 years before we start
receiving a continuous stream of photos and information.
In 2009, NASA launched the Kepler spacecraft.
Kepler was designed to monitor the luminosity of hundreds of thousands of stars with the
aim of finding Earth-like exoplanets.
It works like this.
Pick a star.
Observe the star over a long period of time.
If the brightness of the star dims, congratulations, you've just found yourself an exoplanet.
Over the course of it's mission, Kepler found thousands of planets using this method
but it also found something strange.
The luminosity of a star known as KIC 8462852 was observed to decrease by as much as 22%.
As a comparison, a Jupiter-sized planet would only have caused about a 1% decrease.
What's more is that the dimming of the star could not have been caused by a spherical
object such as a planet because the dimming exhibited an irregular and asymmetrical pattern.
This is what it normally looks like when a planet transits a star.
A short symmetrical dip that lasts for a few hours at most.
This is what some of the data from KIC 8462852 looks like.
In March of 2011 there's a gradual dimming of the star that lasts for about a week before
returning to normal in a matter of days.
Its luminosity is decreased by up to 15%.
Beginning in February 2013, theres a whole complex of dips that last for over 3 months.
The dips are extremely irregular and varied with some lasting for a couple of days and
others lasting more than a week.
And at one point, the star's luminosity decease by a whole 22%.
Multiple hypotheses have been proposed but none can fully explain all aspects of the observed data.
The leading hypothesis is that the star is surrounded by a swarm of cold and dusty comets.
Another idea is that the star is much younger than previously thought
and could thus be surrounded by a protoplanetary disk.
Then there's the more extreme explanation.
Aliens.
The idea is that an alien mega-structure is blocking the light from the star.
It is highly unlikely but it's still a possibility. Which is exciting by itself.
At least until they inevitably prove that it was just exciting, grey, dusty rocks in space.