Oh No! It's An Alien!

Dear Readers,

Here's another article review I did for an astronomy class a while back. I'm not sure why I'm putting all this stuff on my blog. It might be boring. Whatever.

Oh No! It's An Alien!

Recently I read "Quest for a living universe," an article in the April 2005 issue of Astronomy magazine. The article is about the search for extra terrestial life in our universe. It interested me because everything I've seen before about extra-terrestial life has been in science fiction movies, episodes of the X-files, and I even remember visiting the UFO museum in Roswell, New Mexico. However, this article was written scientifically by a scientist. It's actually a scientific approach to the possiblilty of life beyond our earth.

First of all, the article asks if we will even recognize alien life if we find it. Perhaps it is so radically different than life here on earth or than our Hollywood notions that we wont recognize it. So, this article is not just talking about bug-eyed humanoids with ray guns, in fact, this article mostly talks about microscopic life.

Astrobiologists (scientists who combine the disciplines of astronomy and biology) say that there are 3 properties of life that must be universal.

1) life is a complex chemical system that adapts to survive in its surroundings

2) life is carbon based.

3) Life needs liquid because liquid causes molecules to collide in the right time and way, thus starting life.

Where would this life live? This article says that over 120 extra solar planets have been found arbiting 105 stars. So we look to those planets for life. A we understand life now, a star or empty space is not hospitable.

Scientists study our earth to figure out the secret of life, (ie how it gets started, and what conditions must exsist for life to survive) and then apply the secret of life to other planets to see if it matches.

In our own solar sytem, two possible homes for extraterrestial life have been identified as Europa, a moon of Jupiter, and Mars. Both these places, "have- or once had- liquid water as a biological solvent." The article says further that water once flowed on Mars. In fact it would be a great idea to dig deep into the surface of Mars to see if there was water deep down there or fossils or other hints that there was once life there. But we have neither the technology nor the finances to perform such a mission currently. One interesting idea mentioned in the article is that some people believe that life in this solar system began on Mars, not Earth. Somehow, with a big collision or something, that life travled from Mars to Earth and set up camp. Maybe wer'e really Martians!!

In Europa, astrononmers are pretty sure that water was once there and that life could have been there.

But how do we identify life outside the solar system- the places we cannot physically reach with a space ship?

The answer: look for signs in the light they give off. The article says, " Living organisims mess up the chemistry of their enviornment." So somehow, in a complicated way, scientists could get a glimpse of life through the chemicals being put off by a planet. But unusual chemistry from a planet does not necsescarilly mean life has been discovered; there are other situations that can account for unusual chemistry.

Most agree that temperature is the most important element for deciding whether or not a planet is capable of providing a habitat for life. If it is extremely too hot or too cold, chances are that it is an inhospitable planet. Also, if a planet undergoes a rapid change in temperature, organisms probaly couldn’t adapt quickly enough to survive.

In conclusion, this article was'nt about UFO sightings, and it didn't really give any scientific evidence that there is life out there, probably because there isn't any scientific evidence for that yet. The article simply asked and answered the question: "what conditions are needed for life to be on other planets?" Right now the data is inconclusive, so there's no need to yell "Oh No! It's An Alien!"

1) This sort of relates to what we are studying because it's a scientific approach to answering a question that I'm sure many of us as human beings have asked, and it invloves astronomy. The question is: Are we alone in the universe? Just like we can tell what a star is made up of by observing the light that comes off of it, we can guess as to whether a planet is hospitable by the light that comes off it.

2) I learned that Europa and Mars might have had life on them.

3) An unanswered question is: So are there aliens or not?

4) Yes, I would recommend this article to my classmates because I thought it was very interseting and well-written.