aesmael: (it would have been a scale model)

I miss programming. It was the last thing I was good at. Which is not to claim any particular demonstrable level of skill or aptitude. But that one class I took in 2012 I worked hard at, and I got good grades for my hard work. I miss having something I could work at and feel I was making progress in understanding and skill. Unfortunately I keep being too occupied with work and school or otherwise insufficiently self-directed - as well as lacking in inspiration - to pursue further development in learning to program. Or rather, given the long gap of inactivity, re-learning to program.

As one might guess, today I did have some inspiration on a suitably scaled project I might undertake when I am able, and am writing this partially as a reminder to myself that I should do so. In this case I was wondering about where a stationary orbit around Ceres might be located and whether it would be stable.

I realised I could define a succession of more complex versions of the problem which I could automate the solving of. Simplest version would just take mass and rotation period for input and give an orbital radius as output. More complex versions could relate that to the Hill sphere of the synchronous-orbited body and identify whether the radius for a synchronous orbit falls within that range or whether it is outside (and therefore not stable). That would require additional inputs such as the ~planet's semi-major orbital axis and the mass of the star (or other parent body).

Then if getting that working, could add further complexity in trying to get a range of values computed, frex "as the orbited body's rotation is slowed, at what point does the radius of a synchronous orbit fall outside its Hill sphere?" or "at this rotation rate, how near to its parent body can this object orbit and still retain a synchronously orbiting satellite?"

Should be nice sort of project. Fairly simple, already solved problems (I could verify them with pen and paper), well-defined goals that are definitely outside my current skillset. I hope I will manage to get myself the time for working on this. Could feel proud of success.

Originally published at a denizen's entertainment. You can comment here or there.

This is intriguing news.

Am amused by the number of people in comments pointing out Kepler has a selection bias toward detecting multi-planet systems in which the orbital plane is relatively 'flat' compared to our solar system. It certainly does, since the closer planets are to orbiting in the same plane, the better the chance that if one is seen to transit from our perspective, others in the same system will too.

But, the team was expecting to find only a couple of systems where planetary orbits were so closely aligned. So far, they've exceeded that expectation by a factor of 50. That's significant! More than 100 systems with multiple planets observed to transit, when only two or three were expected. Means something new-to-us is going on, because we're seeing a lot more than we expected to even _with_ Kepler's bias toward detecting them.

It is certainly intriguing that these flatter systems have found-planets all sub-Neptune in size. Of course, Kepler wouldn't have detected our Jupiter or Saturn yet, so it may be a bit premature to conclude it's due to a lack of giant planets shaking the systems up. I do wonder if it is true.

Tsk

2011-04-27 22:51

Originally published at a denizen's entertainment. You can comment here or there.

I disagree with the IAU's decision on defining planets, sure. But articles like Should The Cluttered Skies Demote Earth? (and comments of a similar style) make me want to ask people to please stop helping.

Pluto and other 'dwarf planets' have crossed a threshold. Their mass is sufficient that gravity[1] dominates their shape. They are probably all differentiated bodies. So I consider them interesting in ways different to other small bodies, the smaller asteroids, comets, kuiper belt objects, and irregular moons. Besides, in astronomical terms our sun is a dwarf star, but it is still a star.

However. If one looks at the dynamical properties of these bodies, differences between these 'dwarf planets' and the others become sharply apparent. They just don't have the same heft. Looking at the table in that article it is clear that one of the most common arguments against the dwarf planet categorisation - that if you put Earth or some other planet out in the kuiper belt, it would be called a dwarf planet (and that location should not determine what an object is) and thus the whole dwarf planet thing must be nonsense. But according to those figures Earth would have to be moved nearly 3,000 times further from the sun before it would even approach the dynamical insignificance of Pluto or Eris, and that doesn't account for the effect Earth would have had on that region had it been orbiting out there these several billion years - I am pretty sure those figures are derived from the solar system as it is now, not as it might have been.

I do think for planetary bodies a combination of physical and dynamical properties ought to be considered when deciding what to call them. If Ganymede or Titan orbited the sun we'd probably call them planets. If Mercury orbited one of the other planets, we'd probably call it a moon (actually we might call it a double planet if it orbited Earth or anything smaller, but never mind). So I think location matters. Context matters. And arguments like "If we moved X it would / wouldn't be a planet" aren't convincing because they're trivial or false. Nor, to say Earth should be a dwarf planet on account of the stuff around our orbit because the total mass of it is insignificant - in any interaction between them Earth will do the scattering, not be knocked around or much affected. As arguments go, they're pathetic, and I'm embarrassed to see people somewhat on my side using them.

There is an article by S. Alan Stern and Harold F. Levison proposing a planetary classification scheme which meets all of my requirements, and adds some new dimensions I had been hoping for but had not thought of. Although I am partial to major and minor planets rather than über and unter planets the latter set is probably a better choice for not conflicting with our existing use of minor planets. I recommend reading the linked pdf for anyone interested in this topic. It is clear and straightforward, and I doubt I could express it better here. If I were Tyrant of Astronomy I might make that document law and then abdicate. Maybe.

I keep trying to write a description of the proposed scheme here despite what I said immediately above. Probably because I worry people won't follow the link. So, short of copy-pasting large chunks, we simplify: a planet is defined as an object massive enough that its shape is dominated by gravity, but which does not ever sustain fusion. A mathematical test is proposed to decide whether a particular planet is über (dynamically dominant) or unter (not dynamically dominant) in its orbit. Some planetary satellites are considered planetary bodies themselves. Further classification subdivisions are proposed according to composition (rock, ice, or hydrogen) and mass (subdwarf, dwarf, subgiant, giant and supergiant[2]). In this scheme, Earth would for example be a rocky dwarf über planet.

Much of what pleases me about this scheme is its scope for recognising both the variety and the similarities of planets. Pluto is different from Mercury is different from Earth is different from Uranus is different from Jupiter. They're all different from Titan, Triton, Mars and Ceres. But they're all interesting, and have qualities in common which non-planets do not have. Plus, it feeds my sense of wonder and excitement about the universe.

 

 

[1] Along with other details such as their material properties and angular momentum, e.g. 20000 Varuna. Also happens with stars, for example Achernar.

[2] This is fairly directly taken from how we classify stars according to size.

Originally published at a denizen's entertainment. You can comment here or there.

First unequivocally 'solid' extrasolar planet has been confirmed. Others we've found I'm pretty sure qualify, but this is the first pinned well enough it can't be hiding non-terrestrial nature in statistical outlier.

Further details and my news source at Bad Astronomy.

Originally published at a denizen's entertainment. You can comment here or there.

Increasingly less recently I had been discussing with Pazi a game project. I wanted to do something useful so I offered to craft a little program module which could generate 'realistic enough' star systems. Something that would not simulate stellar formation and evolution directly, but which could use information derived from those simulations. I suspect such a tool could find a few uses, all of roughly the same sort, but apart from being useful I mainly think it a pretty nifty idea. Of course I would need to first finish my current project, but that is badly in need of finishing anyway.

Trying to determine what I would consider a 'first finished' version, not the first steps I would take in writing it but what it would need to do for me to consider it getting to completed. That, and some sorting out in my mind of how to approach the workings of this thing.

My thinking is to start with the star itself and build up the system around it in a sort of abbreviated history. Presumably, get it working for single stars before worrying about multiple systems, unless those turn out not really harder to put in. We get a few basic figures for the star, stuff like mass, spectral type, luminosity, then use those to proceed. Stellar mass typically correlates with disk mass available immediately after its formation, determining how much material is available to form planets and potential early migration activity for them. Plus, the distances at which various sorts of planets can form. I think we can relate those figures to get some nice functions for populating planets from. Start by placing giant planets, unless consensus has changed on the order of formation, then the little ones, abstract some pseudo-orbital-evolution and there we have our own impromptu planetary system.

Each planet's numbers - semi-major axis, eccentricity, mass, composition - get to interact with the host star's numbers, and we get a rough guide to the world's likely surface conditions, atmosphere and chemistry of note. There might be more than one class a given world could fall into.

I find the prospect of this fairly daunting. I imagine for an experienced programmer it would fall into the class of 'relatively simple' but for me, it's not. I'm only just barely learning, still. But I look forward to accomplishing this. I suspect the first thing needing doing is collecting papers with relevant modelling statistics to use; been wondering if it might be much harder too to get information for moons and small bodies.

I worry I have somehow done badly by describing my goals in the terms I have, rather than some technical description of coding intentions, but suspect this to be a silly worry. Am expecting to be learning a lot of how in the doing, and believe it is advantageous to have clear ideas on what I want the outcome to be.

Once that 'first finished' version is working I would want to add some fancier abilities, like aging. This would be needed anyway to incorporate giant stars since those again modify their planets as they age and expand and brighten, but also would be useful for incorporating very young stars still in the process of forming planets and details like at what point terrestrial worlds are likely to become tectonically dead. I suppose an approach that might work is to generate values for the whole system's duration (at least, mark points when things change and the values before and after). I suppose it is unlikely this program would get used for anything that depicts time-spans long enough for stars to visibly age, but at least for some sort of manual editing or inspection it would not end up generating a new history every time the age is tweaked. Perhaps too much, but I cannot help but feel it would be a useful approach somehow.

As for populating a larger 3- or 2-dimensional space, I suspect that would be harder to do, maybe want for another tool that talks to this one. Currently I'm thinking finding a good way to place stars in a field would be a more difficult thing to do than getting population kind distributions for various stellar environments. Hopefully by the eventual time I get to attempting that I will know much better.

That's main thoughts and plans on this for now.

[At Systemic can be found an excellent example of why this will likely be difficult to do. At the moment our models aren't reliably predicting the sizes of giant planets in some important situations. And we're still finding situations where our models are in error, which is why I suspect I will have to aim for 'realistic enough' and post refinements as astronomers make refinements. Or as soon after as I am able to.]

aesmael: (haircut)

Originally published at a denizen's entertainment. You can comment here or there.

Large in extent image behind cut )

A new month, so time for a new desktop background. I had been using art shared from other people, but this time chose a screenshot I'd taken in Celestia a few days before.

The perspective is from the surface of Deimos, looking down to Mars below. Much closer than our moon to Earth. If you look along the terminator marking day from night, a white spot is visible. That is Phobos, the other moon, caught in its (less than) 8 hour orbit at a dramatic moment.

Apart from its large crater Stickney (not shown), Phobos is famous for its low and fast orbit, which contrary to that of our moon is decaying lower and faster. When it drops not much lower, tidal forces from Mars will tear it apart and for awhile Mars may be ringed until those fragments rain down upon its surface.

Deimos gets much less love, but perhaps when it is the last moon remaining this will change.

aesmael: (haircut)
Lately have been using this image as my desktop background:

It is an image I took with Celestia two years ago and, coming across again, seemed like good background material.

The main object in the foreground is of course Europa, mostly eclipsing Jupiter in the background. To the left is the Sun, and to the left of that another disk is visible. I recreated this shot in Celestia recently to verify (the time displayed in the image is local to Sydney, so I had to adjust the clock settings in Celestia to get to the right moment, but if you leave them unaltered and enter the time shown you get a shot which is nearly a mirror image of this one) that the other disk visible is indeed Io and not one of the other Galilean moons.

I think it is wonderful that there are places in the solar system we could go and see more than two objects visible in the sky as more than points.

Originally published at a denizen's entertainment. You can comment here or there.

In the past week I have been surprised by two pieces of news concerning Saturn and rings.

First, from the Planetary Society Blog: findings which might be evidence for a posited ring around Rhea. As described in that article, a series of equatorial spots on Rhea bright in ultaviolet light might be evidence of collisions from ring particles orbiting the moon. These particles, if they exist, would occupy a size and distribution which makes them particularly difficult to detect visually directly with the instruments we currently have available.

It seems the idea of rings around Rhea has been around longer than I have been aware of. Apparently they were originally proposed to explain a decreased electron flux in the vicinity of Rhea back in 2005, and I sure didn't realise there was this much evidence already. Would be very exciting indeed to get a direct and definite confirmation about this.

Sadly given how difficult these rings are proving to image, it is unlikely there will ever be beautiful views of the Rhean ringscape. We shall just have to comfort ourselves with the knowledge of something wonderful.

The other news is the discovery of a new ring around Saturn itself. This one, discovered by the Spitzer Space Telescope, is the largest and most diffuse planetary ring yet discovered. The details can be found in this press release. Basically it is very large and very faint, and only detected because of its cool infrared glow. I am concerned that the end of the release specifies this information was gathered before Spitzer ran out of coolant, and whether this means we won't be able to obtain further observations of the ring for a while. It might take us a long time to discover if this ring 'only' spans from six to twelve million kilometres from Saturn, or if that were merely its brightest, densest part.

Apart from the amazement of a whole new feature being discovered, this is particularly intriguing because Saturn's moon Phoebe orbits within this ring and is thought to be the source of its material (via dust knocked off from impacts, most likely). If so, and depending on what else is found, this ring could be a key part of one of astronomy's longer-standing mysteries: the two faces of Iapetus. Although it has long been suspected that material from Phoebe deposited on Iapetus is the reason that moon has one bright hemisphere and one dark (more or less), I think this ring is the first actual detection of a possible mechanism for the transfer of this material.

If that bears out I think I will finally have an answer to a mystery I have been intrigued by since I was a young child; for a long time Iapetus has been one of the solar system bodies I was most fascinated by.

aesmael: (haircut)

Originally published at a denizen's entertainment. You can comment here or there.

Last week seems to have been a good week for news in astronomy. At the least of the sorts that capture my especial interest.

From Universe Today, Spot Discovered On Haumea Rich With Organics And Minerals.

Haumea, one of those planets called dwarfs, is notable for its extremely rapid rotation (a bit less than four hours) distorting its shape well out of spherical and its pair of moons (and the origin of those moons being a probable collision early in Haumea's history which stripped much of its mantle and originated the Haumea collision family). I was thrilled to see such a headline, although on further reading of the article it seems a touch premature:

Possible interpretations of the changes in the light curve are that the spot is richer in minerals and organic compounds, or that it contains a higher fraction of crystalline ice.

So although it appears there is a dark patch on Haumea's surface, we won't know its composition until next year at the earliest. Still, I'm excited to learn just about any new details about these worlds.

Via the Extrasolar Planets Encyclopedia (currently 374 planets and counting), a preprint of a paper submitted to The Astrophysical Journal: The Formation Mechanics of Gas Giants on Wide Orbits.

Presently there are two major theories concerning the formation of giant planets. The core accretion model holds that if a planetesimal can accumulate at least ten Earth masses before the gas of the surrounding protostellar disk dissipates, it will be able to rapidly accumulate a massive envelope of gas. Meanwhile the disk instability model proposes giant planets form when part of the disk becomes unstable and collapses in on itself like a version in miniature of how stars form from giant molecular clouds.

For a while now the core accretion model appears to have prevailed, I think largely because the two models produce different sorts of planets with only a bit of overlap, and most of the planets we have been finding so far suit the core accretion model far better. That is, planets with up to a few times the mass of Jupiter, on orbits less than 10 - 20 AU (Astronomical Units) from their host star.

This paper reminds that there are now planets being found which the disk instability model explains far better than the alternatives - more massive planets approaching the realm of brown dwarves, on orbits too distant for core accretion to have produced them in situ, with orbital dynamics suggesting they were unlikely to have arrived there by scattering from interactions with other planets.

After reading it, I would not be surprised of Fomalhaut b did turn out to originate from core accretion and scattering, but I think they are probably right about the planets of HR 8799 and that there are many more such systems to be found. Would be very interested to learn if there are inner planets to these systems yet undiscovered, and what happens when both planetary formation modes are at work in the same system.

Another quick bit from Universe Today: Smallest Exoplanet Yet Has Rocky Surface. CoRoT-7 b may not turn out to be the smallest planet orbiting an actively fusing star yet discovered, but it is the one with the lowest mass we are currently sure of. The article is definitely worth reading, as some of the details about that planet are amazing.

A picture from Astronomy Picture of the Day, the Andromeda galaxy in UV. Was thrilled to note that in the mouseover comparison, the correlation of UV areas with bright blue starforming areas.

From The Planetary Society, "Richard Kowalski is the first person in history to possess a piece of an object that he discovered in space", an asteroid detected in space and tracked to its impact in Sudan last year. I don't know how I managed not to hear of this at the time it happened, but here is an account from shortly after it happened.

aesmael: (nervous)
Phil Plait has put together a fun list of Ten Things You Didn't Know About Pluto. I still had fun reading it even knowing the items on it already, so definitely recommending people take a look if they want a bit of astronomy for the day.

Going now to look at the other such lists he has done.
aesmael: (sudden sailor)
I wonder very much about continuing these. If I did not, then I would say nothing of most of what I read, and give it less thought than if I attempted to find words for each. If I did not, I would read more, and quicker. I cannot quite shake the feeling that posting these is a pointless mechanical activity, a task continued because it was once set.

These links do not form an entirely honest record. There are items I have read and not noted because I did not wish to give the tacit approval of a link and did not know how to express or form criticism of the content in question.

The reason the majority of these are from shared items is, of course, that I have resolved to first become current with those before reading material of my own subscription.

About.com: Agnosticism / Atheism
  1. Bias and Vested Interest: Interpreting Facts Unreasonably [Well, yes. I strive to avoid this but on good days do not pretend I achieve it.]

Dispatches from the Culture Wars
  1. Even More Political Chutzpah [I suspect most people do not investigate such claims - I know I tend not to, and rely on information provided by those who do.]

Google Reader shared items
  1. Mysterious White Rock Fingers on Mars [via [livejournal.com profile] gentle_gamer. Mars may not be my favourite planet (which is? none, really, the overexposure of Mars or any other location seen as a prospect for life grates on me) but areology is fascinating!]
  2. Because I can't help but make a LIAR out of myself [via [livejournal.com profile] soltice. I agree with this post. That photo is far too pretty for me to quite believe. Really, flower-filled meadows? Wild grass is brown, not green, and never contains flowers. This sort of scene is about as fantastical to me as the elves and snow I read of in stories.]
  3. Inflation Theory Takes a Little Kick in the Pants [via [livejournal.com profile] soltice. The people commenting (at least at first) do not seem have understood what they read - the main claim is that a previously thought clear test for inflation has been found to produced by other sources too, and thus detection of this gravitational radiation cannot easily be taken as confirmation of the theory.]
  4. Industry execs sound IPv6 alarm - is the sky really falling? [via [livejournal.com profile] soltice. Mm. I tend to be wary of people saying we have plenty of time to deal with a foreseen problem. Often, it seems solving it takes longer than projected.]
  5. HP Mini-Note gets unboxed, causes extreme jealousy [via [livejournal.com profile] soltice. Presumably this computer is a big deal.]
  6. Let's all pack up and move to Great Britain [via [livejournal.com profile] soltice. Odd seeing posts from feeds I have subscribed to shared by other people, and not reading them more directly. this comment sort of seems on the nose to me:

    "Us Brits aren't precisely an areligious lot - most of us have some sort of faith, but it's so vague and noncommittal that it passes for atheism.

    You know the kind of thing - "I believe there's something comforting out there but I don't know what it is and whatever it is I'm not going to let it affect my life. It's just nice to believe sometimes."

    So, when Brits say they're afraid of "religion", what they're really afraid of is passionate religion. And seeing as Anglicanism is by definition almost never passionate, they're afraid of other religions being passionate. And in practice that means...Islam.

    When my countryfolk talk about the evils of religion, they're talking about mosques, the Quran and ramadan. But what they're thinking about is bombs.

    So you see we're not so elightened after all."
    ]

    Pam's House Blend
    1. NYT article on convention bloggers features Pam's House Blend


    theinferior4+1
    1. Border Crossings
aesmael: (tricicat)
Although the galaxies depicted in Stargate: SG1 and Stargate: Atlantis exhibit a remarkable frequency of terrestrial, habitable planets, it is also notable that such worlds in each galaxy exhibit generally a distinct, consistent terrain.

Specifically, nearly every world on each show is a forest, and the same forest within the show, but a different one between shows. Clearly significant - this researcher thinks the Atlantis forest looks greener and has higher resolution leaves than the SG1 forest, and possibly indicative of seeding by a hitherto unknown precursor species separate to the Ancients, or possibly merely a shift in Ancient aesthetic.
aesmael: (it would have been a scale model)
If it did not taste so good with every drop, surely we would stop drinking it.

Since it was not visible from here, I am going to watch the lunar eclipse via Celestia. Celestia is being finicky in GNOME and KDE. Going to try installing the GNOME frontend, see if that helps. Also xorsa because it looks fun.
aesmael: (haircut)
    From this post I learn there is a small chance of a recently discovered asteroid colliding with Mars. Naturally I went to my own favoured sources to get more information.
    Anyway, there is news here. Numbers are all there. The object is about the same size as the one that exploded over Tunguska in 1908 but since Mars has a thinner atmosphere than Earth, if it hits it is expected to make a crater roughly 1 km in diameter.
    There have not been many observed impacts, however, so if this object (2007 WDS) does hit
 it will be a good opportunity to test the models that have been developed in the past. Previous impact possibilities (aimed at Earth usually because that is where we are and where we look to guard) have on further observation negligible chance of impact (with one possible exception). It is likely that further observations and refined orbital predictions will also lead to the conclusion 2007 WDS is going to miss Mars but from what I have been reading most scientists are hoping it will hit.
    It seems odd to me at first thought, to be hoping for catastrophic change to a planet's surface, but then I am quite preservationist in instinct. There is no conscious agency behind the asteroid's movement, which would be one of a few more momentous discoveries than an impact and a large part of my initial concern over such an event comes from my perspective in time, I think.
    Humans are ephemeral creatures, our culture barely less so. There have likely been several such impacts on Mars - indeed, on Earth too - since the beginning of recorded history, but not since we have been able to detect them in advance. Over longer timescales this is insignificant, a commonplace and minor occurrence, but possibly a fascinating opportunity for us to learn from.
    This post suggests that the impact flash would not be visible from Earth, but fortunately we have a number of probes available to collect data on-site. The projected impact site is even near to the area being explored by the Opportunity rover, although not so near that the rover itself is in danger. I wonder if it would be able to return any images of the event.

    Perhaps seeing the creation of a crater roughly this size by an object only 50 m across would remind governments of the importance of funding projects to survey the sky for objection which might impact Earth, such as the one which discovered 2007 WDS.
    I should note that 2007 WDS was discovered after its closest approach to Earth, as is often the case.

Spin

2007-08-25 02:08
aesmael: (sudden sailor)
    After my lab this afternoon I was unwinding by catching up on this paper. The short of it is, the authors have looked at the distribution of angular momentum in planetary systems with only one known planet and found a correlation with mass - those planets with mass greater than twice Jupiter's also have high specific angular momentum and vice versa.
    They also found a correlation with the semi-major axis of the planet's orbit, which would be expected since planets with smaller orbits also tend to have lower mass. The hypothesis offered is that lower mass planets lose angular momentum more easily than higher mass planets and thus are more likely to migrate inwards.
    Well, that is mostly summary. The graphs at the end of the paper illustrate the trend quite strongly. Of course, this paper does not look at multiple planet systems, but they promise to examine those in a future paper. I look forward to seeing if this finding persists.

    And right now I have no idea what mechanism might be responsible, nor is one proposed. I wonder if it extends all the way down the mass scale and how many terrestrial worlds could have been swallowed by their sun?

    A few other interesting looking papers were referenced in this one Hopefully I will have time to check them out too.
aesmael: (sudden sailor)
    Planetquest reports on the discovery of the largest known extrasolar planet. TrES-4's mass was found to be only 0.84+/- 0.10 that of Jupiter but its radius is 1.674+/-0.094 Jupiter's. That is, well, large. It works out to ~119,680km (radius, not diameter) if I am lazy and use Wikipedia and Jupiter's equatorial radius.

    Aaaanyway, for a long while Jupiter was thought to be about as large as a non-stellar object could get because as mass is piled onto it (pretend you are an advanced alien civilisation that puts stuff on other stuff for fun), the increase in its gravitational field balances its tendency to expand, so that even brown dwarfs many times Jupiter's mass are nearly the same size. It is only when the object is sufficiently massive for fusion to occur that hydrostatic equilibrium shifts again and the object 9star, now, or young massive brown dwarf) expands to much larger size.

    Well, this is what was thought when the prevailing opinion was that all gas giants exist comfortably far from any stars, much as Jupiter does. Then we discovered the solar system is not as ordinary as we thought and a great many giant planets orbit their stars with suicidal closeness. External heat sources can do the job of internal ones in a pinch, so many of these 'hot jupiters' (yes, that is what they are being called these days, those wacky astronomers - I can imagine people in the distant future talking about jupiter this and jupiter that and not knowing where that particular technical term came from) are larger in size than our Jupiter, even though they tend to be lower in mass.

    Of course in the years since models have been developed to explain the expansion of superheated giant planets, but one of the things that make TrES-4 so interesting is that it is actually larger even than those models predict, so I am very much looking forward to finding out why.

    ...

    People like facts and figures, right? TrES-4 has a density of ~0.2g/cubic cm, roughly the same as balsa wood. It and its host star - which is more massive than Sol and thus entering its giant phase despite being about the same age* - are around 1400  light years distant and its temperature is about 1600 K. Its orbit is only about 4,500,000 km from the surface of its sun and its period is roughly three and a half days.

    Happy now? ^_^

    Love,
          Tricia Fakename

*This world, the same age as our own, is at the end of its natural lifespan. Superheated and boiling away, it will soon be swallowed up and blasted out existence by the death throes of the star which gave birth to it.
aesmael: (sudden sailor)
    Lots of instrumentation information here as probes study Mars during one of its famous dust storms. The rovers, however, are in an endurance race. Will battery power be sufficient for them to continue operating until the sky clears?

    I did not know the HiRISE team has a blog until I read that article. Now I am wondering how many other missions and instruments have blogs I could be reading to keep updated.
aesmael: (haircut)
    Emily Lakdawalla reports on the recent discovery of four (as yet unnamed) moons orbiting Saturn. So far that makes 60, none of which can make a decent cocktail.
    These new moons, like many of Saturn's, are about half the size of Deimos, which is pretty small. The curious should click through if they wish to see an animation of the discovery images for one of the newly found satellites.
aesmael: (Electric Waves)
Religious belief in Australia is falling, sadly more from apathy than anything else, I think. Our local media seemed not so excited about it but PZ Myers is positively emerald. ^_^

Steinn Sigurðsson|Dynamics of Cats has been to a conference and oh how I envy him. I mean, he has to endure terrible hardships, but just look at the conference highlights he has posted so far here (+!), here (amongst other things, Barnard's Star appears not to have any candidates so far so no Barnardian eels, alas, while Proxima Centauri may with further inspection) and here.

I won't say much because, really, all I have to go on are the quick bullet points he has posted so far, but I have not been so hungry since the last time I was in a really good bookshop. A lot of this is amazing and fascinating and the more information we get on the population of planets out there the more wonders we know.

If I were to go into academia this is what I would study, but alas I lack the skills and the dedication, so I will just sit here on the sidelines. :-P

And now it is off to sleep for me. Keep well, people.

Love,
    Tricia Fakename

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