Thursday, November 29, 2012

How do we know what we do?

Do you ever wonder how we are able to know what we do about these objects that are such large distances from us to the point where light takes thousands of years just to travel from these objects to us. Well when visible light can no longer be used to study these objects we use what is called far-infrared which works off the fact that thermal radiation of interstellar dust contained in molecular clouds will begin to glow when infrared light is shined on them. This means that they can be detected long before the visible light ever makes it to the earth from these distant objects and allows us to continue studying objects at the deepest parts of the universe. Just think of how far these distances are. It is truly a remarkable feat.

The Sun

There are billions of stars in the universe, yet there is one that out weighs all the others in importance to us and is studied far more then the others and that one is known to us as the sun. It is pretty obvious why though that one star is responsible for life on this planet and is way closer to us then any other star. This colossal mass is actually considered a pretty average size among stars, but in terms of its importance to us it is larger then all the other stars in the universe. Imagine if this star didn't exist none of us would it's a crazy thing to think about. Isn't it?

Geocentric universe

Have you ever wondered how it was found out that the earth revolves the sun? Well at one time this was unknown until a man named Galileo came along. He was highly criticized for his views especially by the church because they seemed to go against there teachings, but eventually his views were confirmed and now we know how the solar system is arranged and that we are not at the center of the universe and it all started with a man who was willing to challenge the social norm and risk everything in his time.

Monday, November 26, 2012

The Zodiac

The Ecliptic
    Ah, the Zodiac.  A prominent part of astrology, the zodiac is a set of 12 equal divisions along the ecliptic, or path the Sun passes along as the months pass (red line in the diagram to the right).  Each division is associated with a different constellation, even though the constellations vary in size. 

    In order, starting at 0°, the signs are:
    Ares ♈, Taurus ♉, Gemini  ♊, Cancer , Leo ♌, Virgo ♍, Libra ♎, Scorpio ♏, Sagittarius ♐, Capricorn ♑, Aquarius ♒ and Pisces ♓.

     Fun fact:  The divisions are set up such that the spring equinox occurs when the sun enters the sign of Ares.  This is great, until you take into account the precession of the equinoxes, which is slowly moving the signs (the sign Ares is now in the constellation Pisces). 

Monday, November 19, 2012

The Planets: Where are they now?

   A few days ago, I mentioned exoplanets.  While it can be fun looking for new worlds, sometimes it's more fun to look at the worlds closer to home.  So, as per the mnemonic: My Very Educated Mother Just Served Us Nachos, here's where the 8 planets are in the night sky.

    Mercury:  Mercury is currently hidden by the sun, but may be visible in the morning sky later in the week.

    Venus:  Venus is one of the easier planets to spot in the sky, due to being exceptionally bright. It currently rises before the sun, and is visible shortly before dawn.

    Earth:  Look down.

    Mars:  Mars is visible at dusk in the Southwestern sky, but is rather low.

    Jupiter:  Jupiter is high in the sky this month, so look for it in the constellation Taurus.

    Saturn:  Like Venus, rises before the sun, so look for it shortly before dawn.

    Uranus & Neptune:  Due to their distance, these two are difficult to spot without binoculars or a telescope.  That said, they can be found in the constellations Pisces and Aquarius.

Also, when you're out looking:  Saturn and Venus are scheduled to be very close together in the sky soon:  Look for this conjunction on the mornings of November 26th and 27th.

Happy hunting!

Friday, November 16, 2012

Astronomy wants you!

... to go find more exoplanets.

    If you keep tabs on astronomy news today, it feels like every week some headline has to do with the discovery of some new exoplanet.  A few recent finds, in no particular order:
- Possible rogue exoplanet
- Possible habitable planet
- 'Super-Earth' exoplanet

    So, what's an exoplanet and why do we care?  An exoplanet is any planet outside our solar system.  As for why we care?  Exoplanets have the potential for many things, ranging from supporting intelligent extraterrestrial life to being potential mining sites to augment our planet's supply of rare elements.  Somewhere in the middle, of course, are the planets suitable to support human life that we could colonize. 

    While we already know of quite a few exoplanets, very few of them have even a slim chance of being habitable.  By finding more, we increase our odds of finding a habitable planet, and thus finding either extraterrestrial life or a nice new world to colonize.

    Happy hunting!