The article "How
Common Are Habitable Planets? One in Five Sun-Like Stars May Have Earth-Size,
Potentially Habitable Planets” by Robert Sanders talked about how he and his
team at Berkeley in California were able to approximate how many possibly
habitable planets there are. This research was done in order to answer the
question of how many lukewarm Earth-sized planets there are that will not freeze or
vaporize, but remain with liquid, which is pristine for life. The spacecraft
Kepler was launched in 2009, and has been used to look for planets outside of
our solar system that cross in front of their stars. Out of 150,000 plants that
were photographed, a mere 3,000 are candidates; many of them happen to be much
larger than Earth with thick atmospheres, or come to close to the sun, getting “baked.”
Now the scientists began to look at the stars, checking for brightness and also
to calculate the planets’ diameters that cross in front of the sun. They looked
at 42,000 stars, many of which were smaller than the Earth as well as cooler,
where 603 candidate planets were found. Out of these planets only 10 were found
to be Earth-size. These were the planets that had suitable temperatures for
life meaning that the planets receive up to four times Earth’s sunlight or a
quarter of the Earth’s sunlight at least. Although this gave them a good idea of
the number of planets, it was missing the fact that they could have missed
planets due to the fact that not all planets cross in front of their stars, a
small portion in fact! Using a software, they were able to estimate that 22% of
sun-like stars in the galaxy have Earth-sized planets that are habitable. All
of the candidate planets are located around smaller stars known as K stars, but
they can grow into larger G stars like our sun. Unfortunately, Kepler didn't
survive for an extended mission and couldn't track habitable Earth-sized
planets near G type stars. This research team believes that the nearest
Earth-sized planet may only be 12 light years away.
This
article shows how planets like Earth that could be habitable may not be so far
away and that there is a good percentage of possible planets. This could mean
possible life nearby to Earth. Unfortunately, many of these planets are located
around smaller stars, and not all have the same temperature as Earth varying
from 4 times to 0.25 times Earth’s light. This also shows how unique Earth is
and how it is very hard to find an exact match for Earth with conditions habitable
for human life. This article shows how only 22 percent of sun-like stars in the
galaxy have Earth-like stars. This may end up being a really small number
considering there are lots of different sized stars, so only some will be
sun-like stars, and on top of that, less than a quarter of these stars have
Earth-like planets. On top of that there is a large range of what “Earth-like
planets” are; they have to be one to two times the size, and receives 4 times to
0.25 times the amount of light that Earth does. These numbers and percentages
show how the planets could differ greatly from Earth in both size and
temperature, so it can be assumed that there is a much smaller percent that are
around the same exact size and temperature as Earth.
I think
that the author did a very good job or presenting the data from the research. I
really liked how all the steps to calculating the percentage of planets was determined.
I would have liked to know why astronomers and scientists haven’t discovered
one of these planets yet, if one is supposed to be only 12 light years away,
since we are already looking farther into space than that. One thing the author
did that I didn't like was that he included a lot of quotes from people without
explaining who they are, or the significance of the information quoted. I also
think that although the numbers helped, some were unnecessary, and didn't
really need to be put in, or were repeated. Overall, I thought the information
was well presented and very informative.
Sanders, Robert. "How Common Are Habitable Planets? One in Five Sun-Like Stars May Have Earth-Size, Potentially Habitable Planets." ScienceDaily. ScienceDaily, 04 Nov. 2013. Web. 06 Nov. 2013. <http://www.sciencedaily.com/releases/2013/11/131104152720.htm>.
I believe that this review was generally extremely well written. You incorporated many of the facts given throughout the article, while at the same time making it interesting to read. The points you made were very detailed and clear. Your review was also very easy to understand, allowing it to be more enjoyable to the reader. Besides that, your connections to life were great. Your review made me think about the possibility of one day finding a planet that will be able to support life. I never knew how many planets were out there in our galaxy alone. I found it especially interesting that 22 percent of sun-like stars in our galaxy may have Earth-like, habitable planets around them. I found this fact amazing. I never thought about how somewhere not to far off from Earth, it is suspected that tons of other Earth-like planets exist, and maybe one day could be able to support human life. Another fact that you mentioned in your review that I was intrigued by was the difference between the total numbers of planets to the planets that were Earth-sized. This started at a mind-blowing number but then shrunk down to only 10 Earth-sized planets. Overall, your review was amazing and I can’t think of anything you could change to make it better. The only one comment I have for you is throughout the review there were little mistakes, like missing an apostrophe in contractions. But I could not find anything really significant to the quality of this review. Amazing job!
ReplyDeleteThis sounds like a very interesting article! You did a very good job in explaining what a habitable planet is. You talked about how its size, distance from the sun, and atmosphere have to be in such a way that liquids will stay liquids, and the planets will not freeze nor vaporize. This information is crucial to help understand the rest of the article. Also, it was a good choice to start off with this information so the reader would have an easier time understanding the rest of the article. Another aspect of this article that you did a good job in presenting is that fact that of the 150,000 planets photographed by the Kepler spacecraft, a very small number of planets have what it talks to allow life. Instead of going straight to the fact that only 10 planets photographed were Earth size and have suitable temperatures for life, you started by stating the number of stars that had possible planets, and slowly narrowing it down to the final ten. By doing this you gave the reader a good perspective about how special conditions have to be to have life. A third aspect you did a great job of presenting was how the Kepler spacecraft’s data had room for error. You explained how it could only count the planets that passed in front of their stars, and that it did not survive long enough for an extended mission. I was impressed by the fact that we can build technology advanced enough to look that far into space and have accurate calculations. I also learned that the nearest Earth-like planet can be a close as 12 light years away. This is a very far distance, but in the future, many scientists hope to be able to travel this distance in a short time. You did a great job on this review, but one recommendation I have is that when you are talking about the “K stars” and “G stars” to try and go a little more in depth as to what the system is for measuring the size of a star.
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