A future collision billions of years in the making

Although the universe is expanding, collisions happen all over. Planets collide, stars collide, meteors and comets hit planets, etc. However, sometimes larger "collisions" occur where no objects actually hit each other, but it's more of a merger. This can occur between galaxies and we have observed it occurring in different parts of the universe. Our galaxy, the Milky Way, is currently on a collision course with another galaxy called Andromeda. We know this because of the method of measurement used to determine how far away galaxies are from us. Edwin Hubble and other scientists in the 1920's, using the Doppler-shift method, observed many of these galaxies moving away from us at very quick speeds. They were able to deduce from this that the universe is expanding. This also became known as Hubble's law. However, Andromeda looked different in the observation.

Using this method of measurement, it was discovered that Andromeda is headed right for our galaxy. This collision, or merger, will not occur for another four billion years. However, if the earth is still here, it will drastically change what our night sky looks like.

It is unlikely that the stars in each galaxy will collide as they are very spaced out since these are two massive galaxies. I wish I could be here to see it because a night sky like that would be even more incredible than what ours looks like now!

Our Nearest Stellar Neighbor: Proxima Centauri

Let's take a moment to try to understand how vast the universe we live in truly is. Our earth is 24,901 miles in circumference. It is one planet of eight in our solar system. Our solar system is part of one star system. This star is known as our sun. Its gravitational pull causes all of the celestial objects in near proximity to orbit around it. This, along with the rotation of the earth, gives us our days and our nights. However, the sun is not the only light-bringer to the universe. We are surrounded by many of these stars yet they are too far away to really get the effects of their existence. This blog post tries to put that into perspective. Our nearest neighboring star, otherwise known as Proxima Centauri, is 4.243 light years away. As I have stated in my previous blog and many of you already know, a light year is how far light travels in one year. Considering that light travels exceptionally fast (almost 300 million meters per second), that is a great distance. But in the vastness of the universe, 4.243 light years is a stones throw away. We hope that one day, if the earth is uninhabitable and that the planets in our solar system cannot sustain life, that we can travel to this star system and inhabit it.

This may seem completely unattainable at this point in human existence, but it does not put it out of the realm of possibility. Scientists have studied our universe for decades and it seems that it is just under 14 billion years old. It is also 93 billion light years across, the observable universe, that is. So, when talking about distances this great, 4.243 light years doesn't seem that far away. Right now, Voyager I is on a path to a star system. It is travelling at 38,000 mph and is 11.7 billion miles away from us after 40 years since its launch. However, it will not reach this star system for another 40,000 years. The hope is that we can advance our space travel capabilities to the point where 40,000 years can turn into 20-40 years. This rate of travel would still be slow for intergalactic travel, yet would make it viable for expanding our species to other planets outside of our "mini" system of planets.

The use of SETI and the question of 'if aliens are trying to contact us as well, are they using the same method?'

The Search for extraterrestrial intelligence (SETI) has been occurring since the late 1800s. In as early as 1896, Nikola Tesla used his new wireless electrical transmission system to try to contact "beings" on Mars. This is basically how it all started in terms of the search. Even though his search failed, his curiosity using the radio technology has expanded the search greatly in the last 100 years. We now have radio telescopes all over the world that are beaming at hundreds of thousands of stars searching for radio signals that could be coming from an intelligent life-form. Radio signals penetrate the Earth's atmosphere very well, which means that we can beam those signals very far out into space and receive signals from very far away as well. This is why they believe it to be the most effective method in searching for intelligent life in the cosmos.

Now, the only thing that we do not know in the hunt for intelligent life is that if an intelligent civilization that is looking to make contact is using the same technology or not. It could be possible that other potential life-forms out there are using a different kind of technology to send messages that we have not discovered yet. This poses a problem because we could be looking right through potential habitable planets with intelligent life. However, many scientists believe that since they would be governed by the same principles (laws of physics), they should be utilizing radio waves as a means of long distance communication as it is very effective at long distances. The search continues and we will not be giving up anytime soon. However, I just hope that if we do make contact, it is not us giving away our location to a violent civilization that is way more advanced than we are (see movie Independence Day).

The ninth planet

As many of you probably know, Pluto has been declared a dwarf planet. This was declared by the International Astronomical Union (IAU) in August of 2006. The reason for this is because other celestial bodies of similar size have been found in farther reaches than Pluto's orbit. This made the IAU decide that instead of continually adding new official planets to our solar system, we would have a subclass of dwarf planets instead.

Now, this brings me to the point of this blog post. In 2014, researchers stumbled upon this find by accident. They were viewing different dwarf planets farther out than Pluto's orbit and discovered something odd. Each orbit had a strange wobble to it that couldn't be explained. The probability that all of the orbits are doing this naturally without any other mass affecting it is about .007. This is a very small probability. So what scientists and researchers have determined, is there must be a large planet out there affecting the dwarf planets' orbits. This planet would be roughly ten times the mass of earth or about three times larger in overall size. Now before we get too excited about this discovery, it is still just a speculation since it hasn't been viewed directly. However, the evidence is definitely pointing towards this being a true ninth planet in our solar system even though it's way, way out there. The estimation is that this super-earth or super-neptune, depending on it's physical makeup, takes 20,000 years to orbit the sun. It also never gets closer than 300 to 600 astronomical units (distance between the sun and earth) to the sun. This is a massive orbit considering the earth only takes one year to do a full revolution around the sun. I'm hoping to hear more on this discovery and a confirmation that we do indeed have a true ninth planet lurking way out in our solar system.

The discovery of gravitational waves and what it means for science

As many of you have probably heard over the last week, scientists were able to confirm the existence of gravitational waves. These waves were theorized by Albert Einstein over 100 years ago in his relativity theory although he didn't have a way to prove it. The gravitational waves are created when two massive objects (eg. black holes) collide. Right before they merge, they send out a massive wave of energy that is greater than all of the stars in the universe combined. That is an amazing amount of energy dispersed which is almost impossible to fathom. That wave is sent out at the speed of light, but it differs from photons (light particles) since it does not interact with physical matter. This also makes them very hard to detect and why even Einstein wasn't fully confident in their existence. That is where LIGOs comes in. LIGOs (Laser Interferometer Gravitational-Wave Observatory) is a large scale physics experiment in which a laser is split by a mirror and then sent down two tunnels that are two and a half miles long. The split lasers are then bounced back to the original starting point and their light wavelengths are measured. If there is any difference between the two, that shows a detection of a gravitational wave. The reason is because the wave is actually warping everything in such a tiny amount that it actually changes the length of the one tunnel before the other even though it's a minuscule amount.  Now, in order to prove that it truly is a gravitational wave and not some unknown interference on earth, two of these facilities have been built. One is in Washington state and the other is in Louisiana. They are thousands of miles apart because it cuts down on any possible interference or a random anomaly. Since both detected the same disturbance within a fraction of a second, it confirmed a gravitational wave. More of these facilities are going to be built in the near future around the world to make them even more accurate and pinpoint exactly where these waves originate. This wave originated approximately 1.3 billion lightyears away where two black holes around 30 times the mass of the sun merged together.

So, now that I've tried to explain what a gravitational wave is to the best of my abilities, I'll tell you what this discovery means for science. When we look through a telescope, we are viewing the photons coming off of the object we are viewing. Either the object is creating the light (stars) or is having light reflected off of it (moons, planets, etc.). The problem with only using this method to view celestial objects is that light interacts with matter. It can be clouded by gases or dust by the milky way galaxy which keeps us from viewing very distant objects. Since gravitational waves do not interact with matter, we can detect waves that originated from all over the universe. This should allow us to look even farther back in time and help us try to understand the origin of the universe. This is one of the greatest discoveries in science in the modern era. I hope you guys enjoyed my blog and hopefully I can answer any questions you may have in the comments.

The James Webb telescope

The James Webb telescope is the next greatest piece in the viewing of space and celestial objects. It is a telescope that will be launched into space in October of 2018. The Hubble telescope was launched in 1990 and is still being used today. The James Webb telescope is the next generation of telescopes in space. It will be up to 100 times more powerful than the Hubble. This will allow scientists to look even farther into the universe and make more discoveries. The James Webb telescope uses large hexagon shaped mirrors to focus on faraway galaxies and stars. Once completed, the mirrors will be 21.4 feet in diameter. This is much larger than the Hubble's mirror and is made of different material since a Hubble-style mirror would be too heavy to launch into space. NASA's site keeps track of the progress and as of February 4th, 2016, the mirror segments have been fully completed. However, the launch date is still 2 years and 8 months away. I am excited for the pictures it will beam back.


Source: http://www.jwst.nasa.gov/

Kepler mission and the hunt for habitable exoplanets

Human curiosity plays a major role in all of our discoveries. One thing humans are very curious about is if there are other worlds out there like our own. That is where the Kepler mission comes in. In March of 2009, NASA sent off a spacecraft that would be capable of detecting such planets if they do indeed exist. The craft beams back data from 150,000 different stars in our galaxy. The way we know if there is a planet is based on the changes in light beaming towards the craft from the star. If there is a periodic change in light, we know that it is a planet traversing in front of that star. To date, there have been 1,039 confirmed exoplanets. 12 of these planets have been confirmed to be less than twice Earth-size and within the habitable zone. The habitable zone is the section in a solar system where liquid water could potentially exist. Basically, it's in the location where it's not too hot and not too cold in its orbit of the parent star. We cannot view these planets directly, but the light traversing method has been proven to be accurate. It also allows us to understand the atmospheric makeup of the planet which can help determine if the planet is suitable for life. NASA scientists hope to one day develop telescopes powerful enough to view these planets directly.

Sources: https://www.nasa.gov/kepler/discoveries

http://kepler.nasa.gov/Mission/QuickGuide/