Scientists have learned a lot about the universe over the past few centuries due to the diligent work of thinkers like Nicolaus Copernicus, Albert Einstein and Steven Hawking. With every new discovery, however, we are reminded how little we actually know about the mysteries of the cosmos. Copernicus explained that he understood this better than most: “To know that we know what we know, and to know what we do not know what we do not know, that is true knowledge.” What would he have made of our efforts to understand the implications of dark energy and dark matter? Dark matter has helped to shed light on some questions about the rate of expansion of the universe scientists have struggled with for decades. Dark energy, discovered by accident in 1929, is still poorly understood, but some researchers believe it could actually be a property of space itself. As unmanned probes and sophisticated telescopes continue to penetrate the abyss of interstellar space we are sure to be confronted with strange planets, bizarre nebulas and many more weird facts about the universe.
15. Going Rogue
We learn that planets orbit stars just as the Earth orbits our sun, but this isn’t always the case. Lurking in the frozen reaches of deep space are planets that have escaped the gravitation pull any star. A potentially vast, but unknown number of these rogue planets are hurtling through the universe and could potentially enter our solar system or even collide with one of our planets.
14. The Planet X Conspiracy
It sounds like a pulp fiction title from the fifties, but many people think the outer reaches of our solar system may harbor a rogue planet of its own called Planet X. The idea of a “missing” planet in our solar system goes back to at least the middle of the 19th century and most mainstream astronomers have tried to debunk it ever since. However, the idea of a mysterious, rogue planet in such close proximity remaining undiscovered is apparently too intriguing to completely abandon.
13. Density + Infinity = Flat
According to scientists, it is density that determines the shape of the universe. Add up all the planets, stars, asteroids and comets in all the galaxies and divide by the volume of the universe and you get its density. The critical density is the value at which the universe achieves an equilibrium of sorts so it won’t collapse on itself. Even if it won’t literally expand forever, our universe will continue to expand indefinitely. This continuing expansion in every direction results in a flat universe.
12. Who’s Calling? (Can you hear me now?)
Periodically observatories on Earth receive unexplained signals emanating from deep space. Where are they from? and what’s causing them? are two questions the many people are trying to answer. These signals, known as Fast Radio Bursts, (FRB) were noticed about ten years ago and they have since been confirmed to be coming from some very distant and as yet, unknown source. Most intriguing of all perhaps, is that they appear to come from one specific spot in the universe. This has led some researchers to speculate the signals could be from an extraterrestrial intelligence.
11. Mars’ Once and Future Ring
A new theory suggests Mars’ two moons could be all that’s left of a ring system from the planet’s distant past. Named Phobos and Demos, their orbital paths and locations near Mars’ equator could mean they were formed there by violent collisions instead of having been pulled in from the asteroid belt of Mar’s gravity. The theory also suggests that ring formation and destruction is an ongoing process and Mars could in the future once again have a ring.
10. What No One Has Smelled Before (Space, smell you later!)
Astronauts have given us a lot of firsts such as the first man on the moon and the first walk in space. Astronauts are also the first to describe what space smells like. They have variously described it as smelling similar to a cooking steak, hot metal and gunpowder. The thinking is that astronauts bring back certain cosmic particles on their suits and equipment when they reenter their spaceships. The high-energy vibration of the particles interacts with the air causing the distinct odor.
9. Diamonds are a Planet’s Best Friend
In this case, the diamond is actually a planet. There is a planet known as 55 Cancri e that consists entirely of this hard, shiny material. Diamonds are formed from a crystalline structure of pure carbon and make up as much as a third of the entire planet, which is twice the size of the Earth. The dazzling 55 Cancri e is only 40 light years away, but we probably won’t be sending miners any time soon because its surface temperature is about 3,900 degrees Fahrenheit.
8. Fast as a Speeding Star
We all know that stars, like our own sun, are huge balls of hydrogen and are at the center of solar systems. But did you know some stars are racing through deep space all alone at 2 million mph? These hypervelocity stars have likely been kicked out into deep space by the supermassive black hole believed to be at the center of the Milky Way. One theory says these lone stars result when a binary star system gets too close to the supermassive black hole and one star manages to escape, but the other crosses over the event horizon.
7. Proof of Life
While life on other planets has not yet been proven, there is plenty of complicated math to show that it may in fact be a common occurrence. According to estimates, there could be 400 billion stars in the Milky Way galaxy and 50 billion planets. If only 1 percent of these planets are in the habitable or Goldilocks zone of their solar systems, it could mean there are 500 million planets in our galaxy alone with the potential to support life.
6. We Could all be Extraterrestrials
We don’t know how life began on Earth or even if it did begin on Earth at all. A theory known as panspermia suggests that interstellar bodies like meteors and comets randomly seeded planets like Earth with microorganisms. These simple alien life forms eventually evolved into all of the life forms on our planet including us. One version of this theory known as directed panspermia goes on to further state that some advanced civilization intentionally seeded planets with life.
5. Galactic Death Star
The Death Stars in the Star Wars movies are planet killing battle stations. These seem rather silly and insignificant compared to the real “death star” thought to be at the center of our galaxy A supermassive black hole of impossible size and power might be swirling at the center of the Milky Way. This incredible structure pulls in anything that gets too close to its event horizon including entire solar systems.
4. Sounds from the Void
Space is completely silent because sound can’t travel through a vacuum. However, in 2013 NASA studied data sent back by the Voyager I probe launched in 1977. The probe had flown through waves of ionized gas or plasma that envelopes our solar system. Voyager has something called the Plasma Wave Science Instrument that can sense waves of electrons in the plasma. These waves occur at audio frequencies so we can listen to them through a speaker.
3. That’s Gonna Leave a Mark
NASA astronauts last visited the moon in December 1972; this was the culmination of the storied Apollo program. They left rover track footprints and assorted pieces of equipment. There is no atmosphere on the moon so there is no erosion and this means that these artifacts of human exploration could remain undisturbed for as long as 100 million years. Eventually, however, dust will cover the tracks. Large pieces of discarded equipment could remain undisturbed indefinitely including several landing crafts and the rover vehicles from the last three Apollo missions.
2. A Darker Shade of Black
Almost three quarters of the universe is made up of dark energy and experts don’t know what it is. Its presence was discovered by accident in 1929 after astronomer Edwin Hubble realized something was countering the force of gravity – that something turned out to be dark energy. Dark energy is a sort of cosmological constant, but instead of keeping the universe static as Einstein asserted, dark energy allows the universe to continue to expand by providing enough mass to overcome gravity. As much as a quarter of the universe is made up of the equally mysterious dark matter, which means everything else in the universe accounts for only 4-5 percent of its total mass.
1. Introducing Ourselves
The Voyager I spacecraft was launched in 1977 and ever since then has been racing through space at 35,000 mph. In 2012, it left our solar system and continues into interstellar space. Along with the many instruments and sensors, Voyager I is carrying a 12 inch gold plated copper disk referred to as the Golden Record. This disk contains examples of Earth’s diverse cultures and life including selections of various languages and music, sounds of waves and wind as well as depictions of humans and animals. A committee headed by famed scientist Carl Sagan decided what to include on the record. Of course, NASA provided a needle and instructions on how to play the record.