Orphan Planets?

Orphan planets? What a sad thought. A planet all alone floating through space, no "parent" star and no "brother or sister" planets in a nice "home" of a solar system. For a long time astronomers didn't think many orphan planets existed, but new research suggests that Orphan planets may be even more common than stars! (There's 400+ BILLION stars in just our galaxy!) 

 

Artist's conception of an orphan planet

Orphan planets, or planets in general outside our solar system, are not something we can point a telescope at and directly observe. Astronomers have to get crafty and find other ways of detecting these bodies. To find normal planets, astronomers watch a star for a long time, and if they see a periodic dimming of the star then they assume there is a planet orbiting around it (even though we can't directly see the planet.) Finding orphan planets is a bit more difficult though, because these planets are dark and cold and not orbiting a star. We can, however, use a trick I've discussed before, called gravitational lensing, to find such planets. Long story short, if you have a planet floating through space, lets say 20 light years away, and it passes in front of a cluster of stars say 100 light years behind it, instead of dimming the stars, the planet will bend the stars light around it and the cluster will actually look brighter! So if we suddenly see a short brightening of a star cluster, or other distant object, and there is no real explanation for it, an orphan planet may have crossed our path. Astronomers have just announced the discovery of 10 Jupiter sized orphan planets ~15,000 light years away!

Where did these orphan planets come from? The leading theory is that they formed around a star with other planets, but were kicked out of the system soon after forming by gravitational forces of the host star and other planets. So they're pretty much planet rejects that are given up at birth and become orphan…. Wow that's dark. I promise the next post will have a happier vibe to it!

Image credit: NASA/JPL-Caltech

Volcanism On Io

 

Io, one of the Galilean moons of Jupiter, is the most volcanically active body in our solar system. Its surface is littered with volcanoes that produce 100 times more lava each year than those n Earth do. Many of the circular shaped plateaus in the image above are volcanoes, and the dark one just left of center is currently erupting! Io does not have tectonic plates like that crack or get forced upward and cause volcanoes like Earth does. Instead, Io's volcanoes are formed because Jupiter tugs and squeezes the moon as it orbits. It squeezes so hard that the surface essentially pops like a zit and spews out lava (gross!).

Until recently, astronomers were unsure exactly where the magma was coming from. The magma could have originated at the very center of the moon, just under the surface, or anywhere in between. Astronomers used magnetic field data from the Galileo mission (a satellite that orbited Jupiter from 1995-2003) to discover that the magma sits just under Io's surface. The only way that Io could have produced the strange magnetic field signature observed by Galileo is if it has liquid ultramafic rocks directly below the surface. Ultramafic rocks are special rocks that when in liquid form can conduct high amounts of electricity. Earth's mantle is thought to contain a lot of these types of rocks. This magma ocean on Io is probably over 2200 degrees F! I sure wouldn't want to live anywhere near one of those volcanoes!

Image Credit: Galileo/JPL/NASA

Can Aliens Watch TV?

Assume you're an alien civilization flying through space in your fancy high-tech rocket ship, and you stumble upon the solar system. You decide to cruise through, passing each planet searching for signs of "alien life". Your space ship is equipped with a radio telescope, and you point it at all the planets as you fly by. You figure that radio waves are good at carrying information, so any sort of advanced civilization would have figured out how to use them to transmit signals and therefore their planet would glow with radio waves. As you fly by Earth, you point your telescope towards the atmosphere and change any incoming signal to sound waves. What do you hear?

You would probably get a jumbled noisy message of clips from your favorite TV show  mixed with blips from songs on XM radio and search results from Google. Right? Wrong! (Even I though you'd get some radio signals from Earth, so don't feel bad!) The reason Aliens won't be able to listen to XM radio and watch TV is because of Earth's Ionosphere. The ionosphere is the very upper layer of Earth's atmosphere , and is basically a mixture of molecules in a gaseous/plasma state.  When the sun's rays and the solar wind hit the Earth, it ionizes molecules in the ionosphere. When this happens, radio signal is emitted, and the northern lights are created. This happens so often that the amount of radio signal emitted way overpowers any signal produced by humans that leaks out into space. So if you turned this radio signal into sound waves, you wouldn't hear beautiful music…. you'd hear some pretty awful screeching. Astronomers have actually recorded the noise Earth makes. You can listen to it here: http://www.space.com/10296-earth-alien-sounds.html

Einstein's Theory of General Relativity Proved True!

A huge breakthrough in theoretical astrophysics was announced last week, proving Einstein's theory of general relativity true! In a nutshell, Einstein said that the 3-D space we live in plus a fourth dimension of time is linked together as one entity called spacetime. Heavy objects such as stars, planets and galaxies distort spacetime; basically space bends around these objects. Think about putting a bowling ball on a trampoline. The Sun is the bowling ball and the trampoline is spacetime. The bowling ball is so heavy that sapcetime bends around it. Now roll a marble, which signifies the Earth, around the outside of the trampoline. The Earth revolves around the sun because it's essentially trapped in the funnel of spacetime caused by the Sun. That's why all the planets revolve around the Sun.

 

Artist conception of frame dragging due to a black hole

The big discovery that was made was the proof of what Einstein called frame dragging. The theory of frame dragging can be understood using the following example. The sun rotates on it's axis and as it does so, it drags spacetime with it. This slight dragging of spacetime causes the precession of planets. So instead of the Earth following the exact same oval every time it orbits the sun, the oval moves slightly. (Kind of like how you make a flowery pattern using the old spirograph toys.) Until very recently, scientists did not know the origin of this precession, and frame dragging was one of many theories behind it. With the help of a telescope called Gravity Probe B, they were able to prove that large objects like the sun do drag spacetime with them as they rotate, and this causes the precession of other small objects that orbit it.  The details about this experiment are a bit over my head, but the fact that we observationally proved general relativity true is a big step forward in astronomy!

Alcohol in Outer Space?!

 

Sure there is alcohol in outer space! But those of you who are already brainstorming  a marketing scheme for a new drink called "intergalactic buzz" and a practical way of retrieving your new million dollar idea are going to be sadly disappointed. Alcohol exists in both liquid and gaseous state in space, but a majority of what we find is methanol, which unlike is cousin ethanol (found in alcoholic drinks), is not safe to consume.

Pictured above is a region of outer space that contains methanol masers. The masers are the bluish white dots and basically jets of liquid alcohol flying towards us. Titan, Saturn's largest moon, also contains a good amount of methanol (and a little liquid ethanol) on it's surface. It's thought that this moon may have liquid alcohol lakes but the alcohols are mixed together and also cause acid rain.  There is a possibility that some sort of life exists on Titan, and it may be alcohol dependant because of its environment. Maybe if we humans travel to titan someday we will find a thriving civilization of drunk people. Hey, you never know!

Contacting Aliens: The Arecibo Message

For those of you that were around back in 1974, you might remember the sending of the famous Arecibo Message. The Arecibo telescope is a huge radio telescope locate in Puerto Rico. In 1974, the telescope was remodeled, and to celebrate this, Astronomers decided to send a message into outer space! The message was written in binary code (1's and 0's) and sent into space using radio frequency waves. Astronomers used one frequency for the number 1, and another for the number 0. The message is shown in picture form above. It was aimed at a really big and bright cluster of 300,000 stars called M13. The thought was that if there is an alien planet around one of those stars, they would receive the radio message, be able to decode it (since binary is the simplest mathematical language that exists), and maybe send us one back! The bad news about all this is that it will take 25,000 years for the message to reach the cluster, and take another 25,000 years for their response to reach us. So maybe our very distant ancestors will receive a message from M13 one day!

Astro Trivia: Can you guess what the colored pictures in the image are supposed to represent? Leave your guesses in the comment section below! (And don't Google it, that's cheating!) I'll give you a hint, that stick figure in the middle is supposed to represent the human body shape…. Your turn!

SETI: The Search For Aliens!

 

  

The Search for Extra-Terrestrial Intelligence (SETI) is a collaboration of people and activities whose goal is to search for and contact extra-terrestrial (ET) life. When you hear SETI, most people think of the Allen Telescope Array, a collections of 42 twenty foot wide radio dishes that are constantly searching for radio signals emitted by ET (pictured above). Astronomers figure that if ET is at least as smart as we human are, they would have figured out that radio waves can travel very far distances without being disrupted by buildings (or stars, from an outer space point of view). This is why radio waves are used to transmit music to your car. They can hold data and travel far distances without being disrupted. Astronomers think that if ET wants to communicate with us, they will send radio signals into space. In theory, we would receive these radio signals at earth, and be able to decode whatever message was contained in them. Hopefully they are friendly!

It's not quite as easy as it sounds because there are many things in the universe, besides aliens, that emit radio waves. So removing all the "noise" and discovering an alien signal is no easy task. But SETI has been working on this since the 1970's.

Sadly they are currently lacking the funding to continue running their telescopes, and are desperately looking for rich people to donate money…. Too bad I'm not rich!  Hopefully someone will come along and assist with the funds so we can continue to search for aliens!

Stay tuned to learn about messages we've sent to aliens into space, what SETI has found, and how you can help SETI find aliens, without shelling out millions of dollars!

Image credit: SETI