January 25, 2014
Using the Herschel Space Observatory, a far infrared and submillimeter (between far infrared and microwave) telescope, astronomers have detected water around Ceres.
Ceres is the dwarf planet that resides in the asteroid belt, making it the largest object in the area. For those of you who just heard about Ceres, it is not new. Back when it was discovered in 1801, it used to be a planet. Then after a slew of discoveries in the asteroid belt like Vesta, Juno, Pallas, they decided that they were different enough to be labeled asteroids. Then came 2006, and due to discovery of an object larger than Pluto, Eris, and other large Kuiper belt objects, they changed the definition. Ceres was upgraded to the status of dwarf planet because it was round, and revolved around the sun, but did not count as a full planet because it failed to clear the orbit, which is clear since Ceres resides in the asteroid belt.
Now the question is, how did the water get there from Ceres? Well, it is thought that whenever Ceres gets somewhat closer to the sun in its orbit, a jet of water is released in certain areas. The reason they believe that is that the four times they observed Ceres, they didn’t see any water signature once. Not only that, as it was rotating and moving along the orbits, the signals changed, and they believe the likely area of emission are dark spots that they have observed on the surface. While they aren’t sure about this a hundred percent, once the space probe Dawn arrives, they will be able to confirm their findings.
The really cool aspect of this discovery is the blurring between asteroids and comets. Comets are icy objects, and they are the ones that release jets of water vapor. While Ceres itself is more asteroid like, more rock like, its mixture with ice gives it a comet like behavior sometimes. So overall, Ceres has a mix of really interesting features. It is large and massive enough to be planet like, it has asteroid like compositions, and it has its icy bits like comets.
January 24, 2014
First of all, yes, 3 planets doesn’t count as a “planet”, singular, I know, but it sounds better this way… Whatever, on to the topic.
While this is not the first time, it is pretty cool that three planets have been found in an open cluster. This one is called the Messier 67. Open clusters are group of stars numbering in the thousands that are born from the same gas cloud. So for example, Orion Nebula may one day be an open cluster! Anyways, these open clusters eventually dissipate and the stars go on on their own. As for why this is important is the fact that crowded open clusters are believed to be planet unfriendly. That doesn’t mean it is impossible, but it does mean that finding some make them quiet special and fascinating to study at.
All three planets are gas giants. They were found by measuring the wobble of the parent star with the Doppler Shift. While we may not exactly know their size, we know their mass. They are 0.34, 0.40, and 1.54 times the mass of Jupiter. Let me remind you, of course, that all scientific measurements have uncertainties, and the one for the third one is particularly large, plus/minus 0.24. Interestingly, two of them orbit around sun like stars, although slightly less luminous than the sun (sun has luminosity 2, these two stars have luminosity 5). The planets themselves, though, orbit too close. They are the hot Jupiter varieties, and there is nothing like them in the Solar System. That similarity and contrast is what makes those planets very interesting. The planet more massive than Jupiter, on the other hand, orbit a giant star, but farther away. This one has what one might say a more reasonable orbit.
Other than that, there is not much more to say. They happen to be pretty cool because they were found in tight open clusters. You can look at the study, if you want all the nitty gritty details. You can also get a good summary from Universe Today here.
January 16, 2014
KOI-314c is a recently discovered Earth massed planet. Its density is also quiet low considering that the planet’s diameter is 1.6 times the Earth. It was discovered using the Kepler telescope, which detects the dimming of a star as the planet orbits in front of it. The press release I linked above has tons of information about it. Badastronomy also has a great general summary here.
Speaking of planets larger than the Earth, but smaller than Neptune, the most common types of planets to be discovered seems to be those. Thanks to Kepler, we are getting a better idea of the size distribution of planets, at least those that orbit close to the star. Of course, the planets are not going all going to be of the same density. Some might be rocky, others could be icy, and it could also be gassy like Neptune. Based on the measurements of the densities, most of them seem to be the gaseous kind. Another noteworthy point about this discovery is that the Solar System has no planet of this kind even though it is extremely common in the universe. Of course, this doesn’t make the Solar System special, it just got the way it is by the laws of physics and chance. Still, it is a cool fact, and it shows how diverse star systems and planets are.
January 8, 2014
I may write mostly about science, and from the look of this blog, you might think that is my only interest. But I also like videogames. I mainly play Nintendo games and occasional PC games like Civ V. Anyways, I have found this fascinating article about the creation and lifetime of Nintendo Gamecube. There are a lot of information of the decisions the company made and the reason behind them. Basically, tons of stuff I didn’t know.
If you don’t know, Gamecube was Nintendo’s least successful console, and was mainly a niche platform for gaming. It had some great games, but like all post SNES Nintendo consoles, it suffered long stretches of time without software releases. In the case of the Gamecube, well, nothing could save it. Despite that, it managed to make a nice profit for Nintendo, even if the profit generated wasn’t exactly mind blowing. A lot of people who owned it look back at it fondly thanks to some excellent exclusive games.
January 7, 2014
Well, looks like they put all three volumes of Feynman’s Lecture on Physics online! Well, volume 1 and 3 have been around for a while, but volume 2 has finally been posted.
What are they about? You might ask if you don’t know about this. Well, they are transcribed version of Feynman’s Caltech undergraduate physics lectures decades ago. Volume one is mechanics and thermodynamics, volume two is electricity/magnetism and matter, and volume three is quantum mechanics. If you want to read them, I suggest a background in algebra, calculus, vectors, differential equations, and linear algebra. You don’t need to know all of those at the same time, it depends on the area of physics you are covering, but at the very least if you don’t have algebra, you are dead if you read these books.
Overall, it covers a large portion of what physics is about nicely. Just remember that just because you read this book doesn’t mean you mastered the material. It takes doing actual problem sets in order to know how to apply these stuff.
January 5, 2014
Have you wondered what Andromeda would look like if it were a lot brighter? Well, most of you probably haven’t, but it certainly would look incredible (credit for the image goes to this person):
Notice how it would look so much larger than the moon? Now think about this. The Andromeda galaxy is around 2.5 million light years away. Imagine how large it has to be in order to look like that even from that unimaginable distance! In a way, this image gives you a sense of how large 100,000 light years (the visible part, there are invisible parts that stretches Andromeda to 220,000 light years) is, well not completely since such sizes are unfathomable, but this will do.