Friday, March 18, 2011

Super Moon Tomorrow Night!

Get your cameras, telescopes, eyes and coffee ready…. You're going to be doing some moon gazing this weekend! This month's full moon occurs tomorrow night, and this one is extra special. The moon is going to appear 14% larger and 30% brighter than it has in almost 20 years!

Why is this happening? Well, as you probably know, the moon orbits around the Earth in an almost circular shape called an ellipse (fancy word for oval). The moon makes one complete orbit around earth every 27 days, and since the orbit is an ellipse, it reaches a closest point to earth once every 27 days. The moon goes through a phase cycle as well, and we see a full moon once every 29 days.Every 18 years or so, the timing is just right so that the moon is full and it's at its closest point to Earth. Tomorrow is that day! So don't miss the spectacular super-moon tomorrow, because you won't get a chance to see this for another 18 years!

Thanks to Angelica Rodriguez for this post idea!

Next topic: Next Topic: Halley's Comet

Image credit: Michael Richmond, Valerie Rapson, Marcus Freeman; WIYN 0.9m telescope at Kitt Peak, Az

Wednesday, March 16, 2011

The Habitable Zone

As the search for extraterrestrials continues, astronomers have tried to narrow down the best places to look for Earth like planets and human life. To do this they've defined a region in space called the habitable zone.



The habitable zone is defined as the distance from a star at which an Earth like planet can harvest liquid water (and potentially life).  It's often referred to as the Goldilocks Region, because it's "not too hot and not too cold".  Lucky for us, Earth is at just the right distance from the sun to form life. The other planets in our solar system are too hot or too cold to have liquid water, so it's not such a big surprise that we haven't found life elsewhere in our solar system. 

You can define a habitable zone around size of star. Stars bigger and hotter than the sun have a habitable zone farther away from it, while small cooler stars have a closer habitable zone (blue shading on the graph). Astronomers have actually found a few planets that are in the habitable zone around other stars in our galaxy! The problem with most of them is that they are big and gaseous, like Jupiter, and therefore don't have a solid surface for life to live on. There is high hope, though, that  the Kepler Space Telescope (launched last year I believe) will discover Earth like planets in the habitable zone in the next few years!

Next Topic: Halley's Comet

Monday, March 14, 2011

NASA Discovered An "Alien"!


Back in December, NASA announced that they had discovered an alien life form! (pictured above) And guess where they found this alien….. not on another planet, but rather in the good old state of CA. Not exactly what you were expecting huh? Yeah me either, but still this is a huge breakthrough in science.

NASA may not have found a green human like creature walking around on another planet, but what they did find is evidence that makes it seem more likely that such creatures exists. The microorganism in the picture was found in Mono Lake, CA. The lake has a high concentration of arsenic and extremely high acidity, making it a very toxic place for human beings. If you went swimming your skin would melt off in a matter of minutes! But this creature fares much better. What's alien about it you might ask? Well, it has a DNA structure just like ours, but instead of using the element Phosphorus as the backbone which holds it together, it uses Arsenic. (In the picture below replace the phosphate group with arsenic)


Scientists think this is so because the environment it lives in is deprived of phosphorus, and believe it or not arsenic is the closest thing in nature that can replace phosphorus (from a chemistry standpoint).

So what does this tell scientists? Well, it proves that conditions on other planets don't need to be exactly like those on Earth for life to form! It probes the possibility that a planet with arsenic in its atmosphere instead of phosphorus, for example, may still be able to harvest life.Whereas until this discovery was made, any planet that didn't have conditions exactly like those of Earth would have been immediately crossed off the list of planets that may harvest life. 


Next Topic: The Habitable Zone

Image credit: NASA (top)