October 24, 2008

Whole Universe In a Magazine

I don't usually buy magazines at newsstands but this one got the better of me. Discover's Whole Universe magazine is by far the most exoplanetology-centric magazine I've come across so far.
The articles are truly educational and the pictures are amazing. Two of its pages even shows the same image I selected for my past post "Extrasolarise" four months ago.
The only thing I can notice is the inconsistent naming convention of the exoplanet names. I was reminded of the cumbersome process of straightening out the exoplanet duplicates at wikipedia and freebase due to naming convention discrepancies where the space was absent between the star name and exoplanet index. For example, in the article - Forbidden Planets on page 36, Gliese 581d should've been Gliese 581 d.
It's quite trivial I know, and Freebase has now so wonderfully remedied this issue. But leniency to naming conventions would make it difficult to catalog the growing number of exoplanets in the long run.
But still, the magazine is splendid. I would love to come across such a kind of magazine in the newsstands once again.

October 10, 2008

An Exoplanet, its Moon, and Gas Clouds

ExoplanetThis is what hapens when I look too much at exoplanet paintings. Having recently purchased two books that feature the illustrations of Lynette Cook--one of which is Infinite Worlds--I was then inspired to let my imagination run wild, and mess around with Photoshop. What came up was this picture of a terrestrial exoplanet and it's moon with a glowing interstellar cloud in the background.
Both the exoplanet and it's moon is inhabited by alien civilizations. However, the lifeforms on each of them started almost simultaneously, evolved independently and in parallel. Therefore, their ecosystems differ significantly.
The difference in color between the exoplanet and its moon are caused by the distinct chemicals in their atmospheres that are caused by life's unique metabolisms.
The glow in the background is caused by cosmic rays bombarding a giant interstellar gas which cause it to become energetic.
It might be possible that life on both rocks were jump-started and sustained by the energy from the gas cloud.
Basking in an unlikely source of energy, life in this alien planetary system would be so much different than life on earth.
Different. But not impossible.

October 1, 2008

Pluto, Plutoids and Exoplutoids

At first I was saddened when Pluto was demoted from planethood. Then I was amused by the new classification called "plutoids". I love playing with words, but plutoid sounded too funny to me. Why not have Jupiteroid, or even Earthoid? And all the debate that ensued about pluto's demotion just prompted me to call Pluto as the Great Hemorrhoid of Astronomy, because it was painful to "lose" such a planet.
However, we are given a consolation by the fact that Pluto is still a planet in some way, eventhough the IAU denies it being so. Yes, it is actually a dwarf planet, and a first in its class called "plutoids".
So let us examine the heirarchy of these 3 terms: Planet, Dwarf Planet, and Plutoid.
A planet is a round object that orbits the sun. Its large enough for its gravity to clear out the rocks and other debris within its orbital path.
A dwarf planet is also a round object that orbits the sun. But it is too small to have anough gravity to clear out debris in its path. Hence there are other objects sharing its orbital path.
A plutoid in turn, is any dwarf planet that orbits farther out than neptune (a trans-neptunian object or TNO).
Ceres is an example of a dwarf planet. It is round and it orbits the sun in the asteroid belt, along with millions of other smaller objects. Pluto and Makemake are also dwarf planets since they also share their orbital path with other objects , but they are also plutoids, as is Eris. They are plutoids because they orbit farther from the sun than the farthest planet, Neptune.
So currently, some established members of the plutoid class are Pluto, Makemake, Haumea, and Eris. But it could well grow to more than 70 in a few years time as more dwarf planets fall into the class of plutoids.
Unlearning is also part of learning. And this is what progress in Science is all about. Painful and controversial as it may have seemed, the IAU's decision to "demote" pluto was necessary to for a better classification of a bewildering array of celestial objects orbiting our sun. To a certain extent, I support the IAU on their decision (even though it still needs a little tweaking). Most often than not, collective intelligence is smarter than emotions, and I believe it will sway one final tweak to simply put dwarf planets as a subset of the broader term "planet" to settle the debate.
Now what does it hold for Exoplanetology? As it will turn out, the term plutoids would actually make it easier to categorize "extrasolar dwarf planets" that fit in place: Exoplutoids! But it will be decades AFTER planet-hunting capabilities resolve to discovering earth-like planets. Then we may actually discover exoplutoids next.