An exoplanet is a planet that orbits a star other than our Sun.  Even the largest exoplanets are invisible to our mightiest telescopes.  So how do we find them?  Watch and find out:

I’ve known about the solar transit trick for finding exoplanets for some time, but the ability to identify atmospheres had always left me a little perplexed.  After watching the video, I was like,well, duh.  That doesn’t make it any less amazing, though.  Think about it, we have the ability to not only find exoplanets but get a fairly good idea as to what the composition of the exoplanet’s atmosphere and physical makeup are.  And all of it by simply measuring the change in light patterns as the exoplanet traverses its star.

It turns out that exoplanets are much more abundant than ever thought.  It was thought that the norm would be a star without a planetary system, but we’ve discovered the exact opposite.  We’ve found gas giants orbiting their star closer than Mercury orbits our Sun.  We’ve found planets that are almost all water with a solid ice core and a vast ocean and a steam atmosphere.  We’ve even found a few exoplanets that are tantalizing Earth-like.  In fact, around 20% of stars are now thought to contain Earth-sized planets in the Goldilocks zone of its star where it may support life.  That doesn’t mean they’re all habitable, but it’s an enticing promise that there could be a habitable planet circling a star fairly close by.

Of course, there’s a big fat asterisk on the Goldilocks planets.  A lot of this data is extrapolation from what we’ve found so far.  Exoplanets that orbit quickly close to their star are much easier to detect than exoplanets the size of Earth as far away from their star as the Goldilocks zone.  From what I understand, we’ve only found a few actual exoplanets from direct (or I guess indirect) observation.  Regardless, we’re still in the infancy of exoplanetary exploration and detection methods are bound to get better if we can devote more time and resources to this exciting field.

NASA does a lot of work with a little money.  They send rovers to Mars, they launch satellites into space, they observer distant stars and galaxies and they look at the moon.  We often forget about them moon perhaps because of its ubiquitousness in the sky.  That is until NASA informs us that they have recorded the largest explosion ever recorded on the moon.  If you happened to be looking at the moon at the time of impact, you would have been able to see it with the naked eye.  No telescope required.  40 kilograms at 90,000 kilometers per hour.  KER-SPLAT!

Even a casual observer will notice that the moon gets hit a lot.  It’s surface is more cratered than a teenager’s face with acne.  With no atmosphere, the moon takes the full force of any impact from rogue meteoroids.  Any colonization that we do on the moon would almost certainly be required to be underground as a result.

Earth, on the other hand, has a nice atmosphere of various gases that not only allows us to breath and live, but also protects us from the potentially deadly flying rocks that are strewn across our  solar floating in mathematically precise orbits around the Sun just like Earth.  Any of those rocks that try hitting the Earth are met by billions of molecules joyously bouncing off of each other but mostly spread impossibly far apart.  The plunging rock changes this dynamic.  It pushes those molecules closer and closer together where they start bouncing off of each other more and more frequently.  All of this bouncing around causes pressure and temperature to rise quickly.  The higher pressure and temperature start picking away at the death spiraling rock until it breaks apart into fine dust and tiny pebbles that fall harmlessly to Earth.  Well, most of the time.

So, thank you atmosphere!  Your praises cannot be sung enough.  Ballads should be written and stories told of all of your invisible, silent, never ending works.

Commander Chris Hadfield recorded a pretty awesome version of “Space Oddity” while on the International Space Station.  Check it out:

There is a guitar in space!  That got me to thinking.  Your average acoustic guitar weighs about 7 lbs (3 kg).  The cost per kilogram to get an object to orbit is around $10,000.  That means that the guitar cost $30,000 to get to the ISS!

This isn’t meant as a knock on wasteful government spending.  It’s more putting into perspective how expensive space travel is.  A guitar is certainly worth the investment for the astronauts of the ISS.  It provides needed entertainment during their downtime hours.  It’s not like these guys can go out for a walk in their free time.  Not to mention that a guitar in space has brought us this stunning music video!  Well played, NASA.  Well played.

It also got me to thinking about how much modern technology has likely saved us.  You have to assume that a fairly common personal item brought by the astronauts is a book.  Books are made of paper and paper is pretty heavy.  Now, thought, they can just keep a Kindle or two up there to share and have hundreds of books at the cost of only $2,500 (250 g) per Kindle.  And they can just beam new books to the ISS for free!

That’s the beautiful thing about space travel.  Even the most mundane thing as a guitar becomes infinitely fascinating.