Sunday, May 31, 2009
Moon, Venus and Mars - a nice lineup
Not a bad little lineup.
Saturday, May 30, 2009
Don't Forget the "Blue" First Quarter Moon!
3 Quarks daily has a science blogging prize
- The nominating process is hereby declared open. Please nominate your favorite blog entry in the field of the natural and social sciences by placing the URL for the blogpost (the permalink) in the comments section of this post. You may also add a brief comment describing the entry and saying why you think it should win.
- The editors of 3QD reserve the right to reject entries that we feel are not appropriate.
- The blog entry may not be more than a year old from today. In other words, it must have been written after May 24, 2008.
Thursday, May 28, 2009
Watching Things Crash on the Moon
The Lunar Crater Observation and Sensing Satellite (LCROSS) Mission will slam a large impactor into a permanently shadowed crater of the Moon, while its dedicated satellite and a bevy of Earth and ground based telescopes watch, looking for signs of water in the impact ejecta. Earth bound observers won't see the impact, but very well may see the plume of dust and gas that will be blasted out by the impact.
the LCROSS team are calling for amateur observers to watch the impact site as well. I love it when they say:
...the Centaur impact plume may be visible through amateur-class telescopes with apertures as small as 10 to 12 inches.
(Looks at 8" scope, sighs). If you are interested, the current launch and impact times are in a June 17-21 window.
A launch on June 17 results in an impact on October 8 at 10:30 UT.
A launch on June 18 results in an impact on October 9 at 11:30 UT.
A launch on June 19 results in an impact on October 10 at 12:30 UT.
A launch on June 21 results in an impact on October 11 at 13:30 UT.
There is an LCROSS Wiki with more information on observing this impact, maps and impact geometries, and you can stay up yo date with the discussion group.
Wednesday, May 27, 2009
Lecture: "From Earth to Mars: Steps Toward the First Human Mission to Mars"
Dr Pascal Lee, NASA scientist and co-founder of the Mars Institute, will deliver the 2009 American Institute of Aeronautics and Astronautics Distinguished Lecture, "From Earth to Mars: Steps Toward The First Human Mission to Mars," at several locations around Australia from Monday, May 25 through Monday, June 1. These events are free and everyone is welcome.
From the press release:
Dr Lee will examine the what, why, when, and how of a human mission to Mars, with special emphasis on the how. "The first steps towards a human journey to the Red Planet are already underway, as we continue to explore extreme environments on Earth and prepare for our return to the Moon," Dr Lee has said. "Human journeys to near-Earth asteroids and to Mars' moons, Phobos and Deimos, will also help pave the way. In time, humans will be ready for their first missions to the Red Planet."
The times and locations of the lectures are:
- Brisbane: Thursday, May 28, 6:00 p.m. - Raybould Lecture Theatre, Hawken Engineering Building, Cooper Road, University of Queensland, St Lucia (doors open at 5:30 p.m.)
- Canberra: Friday, May 29, 6:00 p.m. - Menzies Theatre, National Convention Centre, Constitution Avenue, Canberra (doors open at 5:45 p.m.)
- Melbourne: Monday, June 1, 6:30 p.m. - Casey Plaza Lecture Theatre, Level 4, Building #10, Bowen Street, RMIT University, Melbourne (doors open at 6:00 p.m.)
Flyers for the appropriate capital city with contacts etc. can be accessed at the bottom of this page.
Sorry, Sydneyites and Adelaidieans, those lectures have already been given, we missed out.
Tuesday, May 26, 2009
Carnival of Space #104 is here.
Labels: carnival of space
Sunday, May 24, 2009
Best Jupiter Yet!
Have to wait for the rain to stop.
Saturday, May 23, 2009
Carnival Of Space #103
Labels: carnival of space
Friday, May 22, 2009
Comet C/2008 Q3 Garrad with globular cluster
Comet C/2008 Q3 Garrad is in outburst, but until recently I haven't been able to look for it due to cloud and rain. I had a go with binoculars last night, but couldn't see a thing, on the other hand the light pollution is worst to the south where I am, and I couldn't pick up anything in the 7.5-8.0 magnitude range near midnight (also, turbulence was really bad, stars twinkling almost to the zenith!). If you want to look, see the spotters maps here.
So I turned to the Global-Rent-a-Scope system (which had also been clouded out until tonight), and got this very nice image of C/2008 not far from the 8th magnitude globular cluster NGC 6362. Image taken with the widefield G12 using a 90 second 1x1 binned exposure with luminance filtering.
Thursday, May 21, 2009
Wednesday, May 20, 2009
I took this image using GRAS-13 from Global Rent-a-Scope.
Tuesday, May 19, 2009
A Moon Hiding in Clouds
Monday, May 18, 2009
Climate Futures Seminar, Wednesday May 20.
Join us this Wednesday for the tenth instalment of the Climate Futures Seminar Series entitled ‘The Carbon Economy’ convened by Professor Christopher Findlay.
This seminar will explore what has to change in Australia’s economy to get to or near the global per capita average emissions needed under ‘ambitious’ mitigation. Policy options and recent changes in climate change policy in Australia will then be discussed , followed by a review of the international context of national policy making, likely events at the Copenhagen meeting, interaction between China and the US on climate change, and the gains from international linking of emissions trading schemes.
‘The carbon economy’ will be presented on Wednesday 20 May at 5-7pm in the Horace Lamb Lecture Theatre, University of Adelaide North Terrace campus. The entrance to the venue is indicated on the first attached flyer. We plan to commence by 5:15pm but doors will be open throughout the event. Registration for this event is preferred.
enquires to: email@example.com
Labels: Climate Change
Moon, Venus and Mars, Thursday 21 May
There will be a beautiful arrangement of Venus, Mars and the crescent Moon on the morning of Thursday May 21 (pictured above). On the Following day Friday May 22, the thin crescent will make another, shallower triangle with Mars and Venus. A good reason to get up in the morning.
Sunday, May 17, 2009
Stunning Image of Space Shuttle Atlantis and Hubble
Taken by Thierry Legault in Florida, you can see the original image here (and the shuttle itself here). You can also catch up on the posts at Astronomy Post of the Day, SpaceWeather, The Bad Astronomer and Dynamics of Cats.
Cosmic Diary - The Origin Of Elements
Making chemicals in the Universe is almost like following a recipe, which is the theme of this feature. Condensing quarks, getting the right temperature for protons and then cooking up elements are all studied. Everything has to be just right to get high quality results and the timings have to be spot on, otherwise you may end up with some very unexpected results...
Labels: International Year of Astronomy
Friday, May 15, 2009
The Moon Again
Thursday, May 14, 2009
The Hunt for Planet X – Book Review
It all started with Uranus. Before Herschel found Uranus lurking amongst the stars, people were quite content with the idea that the solar system contained 6 planets (and an increasing number of Moons, once the shock of Galileo’s discovery of the Medicean Stars had abated). But with Uranus swimming into view, people began to wonder if there were more worlds lurking out there, and hunt them.
So the hunt for “planet X” began, X the unknown, for every discovery of a new world, where X became known and named, there was always another X to take its place in the minds eye, and so the search continues on.
For a subject that evolves over years and in the slow watches of the night, Govert Schilling gives us a rollicking, fast-paced and information packed guide to this never-ending quest in his book “The Hunt for Planet X” (ISBN: 978-0-387-77804-4). I am also envious of his wonderful way with words. One of the big bugbears with communicating scientific information to the general public is how to make it accessible, without dumbing down or oversimplifying. I think he succeeds admirably, generating some memorable images along the way. I have to steal his image of comets as icypoles melting on a footpath.
Almost every aspect of the search for for Planet X is here, from the supposed sun-hugging Vulcanoids, to the discovery of Ceres (briefly a planet before it was demoted), to Nemesis (and Nibiru) the discovery of the Kuiper belt and the giant ice dwarfs, to the the discovery of Pluto and the controversy over Pluto being a planet, it’s all here. Govert Schilling brings it all to life too, the excitement of discovery, the frustration of searching, the personalities of the researchers. People I have known for years as dry names on the mastheads of scientific publications come alive and hope, dream and exult over photographic plates and digital images.
And you learn a lot too, I’ve been reading out this sort of work for ages, following popularisations and scientific papers, but Govert Schilling bought out new aspects for me to understand (I think I finally “get” planetary migration mechanisms now as a result of his explanation). The demolition of the Nibiru myth is masterful too. There are some bits that could do with a bit more detail. Having read “The Neptune File”, his exposition of the controversy over Neptune’s discovery is quite good, but I would have liked more than an assertion that Tom Standage overstates his case.
There is a climax to this book, rather than just a list of (exciting) discoveries. And that is the demotion of Pluto. This thread is masterfully woven into the story; the origin of the solar system and its evolution, the origin of comets, the hunt for ice dwarfs all lead up to the powerful story of the meeting that demoted Pluto. By the end of the book, you can understand why that happened (although you still may not agree with it), and what it means in our new understanding of the solar system.
A fantastic book, get a hold of a copy soon.
Comet C/2008 Q3 Garrad in Binoculars
Comet C/2008 Q3 Garrad is in outburst. It should be about magnitude 13, but is currently magnitude 7.6, easily in binocular reach (although best under dark skies). You will have to look for the comet before moonrise.
The comet is moving quickly, and is in some beautiful territory. The click on the spotters map on the left to embiggen and print. A binocular map is here in PDF format.
Orbital elements and an ephemeris can be found here.
And here's an IceInSpace thread.
Wednesday, May 13, 2009
Speaking of the Hubble Telescope ...
Where do meteors come from?
Where do meteors come from? Mostly in the northern sky, it looks like. This astounding image is a map of meteor images complied by meteor enthusiasts in Japan. Go over to Astronomy post of the day for for the full story.
Tuesday, May 12, 2009
On This Day ....
.... Today, the space shuttle Atlantis blasted off to deliver the final service mission to the Hubble Space Telescope. This service should extend the telescopes life to about 2014, and provide significant upgrade in its functioning. Check Heavens Above to see if you can see the shuttle and the ISS together.
Carnival of Space #102 is here.
Labels: carnival of space
The Mars Hoax Rides Again
No it won't, it's a hoax. See "The Zombie Mars Hoax That will Not Die"
Stereo - Two Comets in One Field
Watching these two is a pleasant diversion while I'm waiting for the Moon to wane and clouds to go away so I can catch C/2009 G1 again.
Hat tip to Comet Al and Wentao Xu.
Monday, May 11, 2009
Climate Futures Seminar, Wednesday May 13.
Have you ever wondered how climate change is impacting rural communities? To discover more join us for the ninth instalment of the Climate Futures Seminar Series and hear from three speakers who will discuss the research being undertaken in this area and its application.
In this lecture Dr Peter Hayman, Principal Scientist, Climate Applications with the South Australian Research and Development Institute (SARDI) will be joined by Barry Mudge a farmer and consultant from Port Germain (north of Goyder’s Line) and Dr Paul Peitrie chief viticulturist with Fosters to talk about risk and resilience in the face of climate change.
This seminar will be presented on Wednesday 13 May at 5-7pm in the Horace Lamb Lecture Theatre, University of Adelaide North Terrace campus. The entrance to the venue is indicated on the first attached flyer. We plan to commence by 5:15pm but doors will be open throughout the event. Registration for this event is preferred.
enquires to: firstname.lastname@example.org
Labels: Climate Change
The Australians War on Science Update and Ian Pilmer's Book
I don't know what to make of Ian Pilmer. A while ago he was involved in the fight against creationism, but by all accounts his latest book "Heaven and Earth" uses the same creationist tactics, misleading, outdate or just plain flase information, again, Deltoid has a good review (and here and here), as does Barry Brook.
Labels: Climate Change
Registrax Multialign feature
Registax, the software I use to stack individual frames from the AVI's I take when astroimaging with my Philips ToUCam, has a "multipoint" registration format. The image on the left was stacked using single point registration, the one on the right using multi-point.
Not a lot between them, although the lava rills are clearer in multipoint.
Sunday, May 10, 2009
Ganymede occulted by Europa
Saturday, May 09, 2009
I took this image using GRAS-13 from Global Rent-a-Scope. Nice.
Thursday, May 07, 2009
Where do comets come from?
Where do comets come from? They scream in from the outer dark, briefly flash across the skies to our wonder then return to the dark. Actually, there are multiple answers to this question. We can divide comets into two basic types, long period comets and short period comets. Long period comets have their origin deep within the outer reaches of the solar system, they will return to the warm embrace of the Sun on geological time scales, if at all. Short period comets come from within the solar system, and can be further divided into Jupiter Family comets, with an orbital period of 20 years or less whose orbits extend not much further than that of Jupiter, and Halley Family comets, with periods of between 20 to 200 years.
Source Hubble Space Telescope:
But this is only part of the answer to “where do comets come from?” Comets are basically dirty snowballs, and as the Jupiter Family comets swing close to the Sun, a little bit of them evaporates. The spectacular (or not so spectacular) tails that awe us are composed of comet material boiling away into space . It’s obvious that comets can’t last forever, and eventually the ice will evaporate away, leaving an inert core of rubble and dust which can no longer be called a comet (or in extreme cases disintegrate into a stream of rubble).
We have examples of comet death in the spectacular decay of comets such as 73P/Schwassmann-Wachmann 3 and the asteroid/comets with feeble tails. The time for a Jupiter family comet to melt away is much shorter than the age of the solar system (around 300,000 years compared to the age of the solar system, around 5 billion years, Earth is around 4.5 billion years old). Any comets present in short period orbits at the formation of the solar system will be long gone by now, but we obviously have active short period comets. Where do they come from?
Source: Wikipedia One of the first proposals was that the short period comets, like the long period comets, come from the icy dark that surrounds the solar system, and represent long period comets captured into short period orbits by interactions with the planets. However, while some short period comets may come from this source, it’s unlikely that most of them do.
Firstly the short period comets are more or less confined to the orbital plane of the solar system (but not as much as the planets), where as long period comets come from all over. Secondly, simulations showed that too few comets could be captured this way to explain the number of comets we see.
On the basis of dynamic simulations, it was predicted that there was a band of icy objects lying beyond the orbit of Neptune, and comets were the results of small icy bodies being bounced into the inner solar system by gravitational interactions with the planets and other icy bodies. A hunt for these objects soon found them , and the discovery of the Kuiper Belt a spectacular vindication of cometary theory. Now, cometary objects at that size are too small to be seen, even by the Hubble telescope, but counts of larger objects found that the size distribution followed a power law (with of course, more objects at smaller sizes than at larger sizes), and extrapolation of the best surveys indicated there was more than enough objects in the Kuiper Belt to account for the number of comets we see today.
Which brings us to this paper by Volk and Malhotra. They have done one of the most exhaustive simulations of cometary dynamics to date, to estimate the necessary population of Kuiper Belt objects needed to produce the number of comets we see today, with some of the best estimates of the actually Kuiper Belt population.
And they come up with a shortfall, there appears to be too few small icy objects in the Kupier Belt to account for the number of comets we see. Now, I’ve been simplifying things a bit. The cometary group they were studying is a subset of the short period comets, the Jupiter family comets. These are the most numerous short period comets. Also, the Kuiper belt is not homogeneous, being made up of the classic Kuiper Belt, the Scattered Disk and various bodies in orbital resonance, such as the Plutinos. The work of Volk and Malhotra refers to the origin of Jupiter Family Comets from the Scattered Disk. Anyway, they concluded that there is over two order of magnitude fewer objects in the scattered disk than is needed to provide the number of comets we see today. The creationists have seized upon this, if we have too many comets they say, and comets cannot survive a long time, therefore the soar system must be young. Lets leave aside the numerous problems with this argument and look at the actual paper for a moment.
Source: NASA and A. Feild
The authors calculate that around 1 x108 objects are required to provide the number of comets we see today, but they estimate that there are only 3x105 comet-sized objects in the Scattered Disk of the Kuiper Belt. This is a fairly large discrepancy, but then we come to the confidence interval. The 95% confidence interval, that is the region where we are statistically confident there is a 95% chance the true number of comet sized objects lies in that region, runs from 1x105 to 2x108.
In other words, our degree of uncertainly about the true number of Kuiper belt objects is so large, that it may very well be sufficient to explain the number of comets we see. Now, I am not a professional astronomer, nor do I play one on TV. But I do do a heck of a lot of curve fitting and statistics, so I am qualified to comment on this.
Why it's hard to count faint Kuiper belt objects Source: Fig1 Bernsetin et al., 2004.
Why is there such a large error range? As I mentioned before, we can’t actually see comet sized objects in the Kuiper Belt, even with Hubble. We have to estimate their number by extrapolating from the size distribution of objects we can see. Early estimates gave lots of objects, later surveys, looking at dimmer objects, gave a smaller estimate. The Volk and Malhotra article uses a Hubble survey estimate, which looked at the faintest objects yet. However, it is very easy to miss objects, as the history of astronomy shows when we have missed very large icy objects (automated systems may miss faint objects, the survey may be looking where objects aren’t etc.). So the Hubble estimates come with very large error bars. Other deep surveys (although not as deep as Hubble) find more objects.
Estimates of small Kuiper belt objects from one of the most recent surveys ( Source: Fig6, Fraser et al., 2008). Note the large error bars.
The very best we can say is that we do not have enough data to make a definitive estimate of the number of comet-like Kupier objects, and we will have to wait until better, deeper surveys are done.
The creationist says
“The simplest explanation as to why we can still see short-period comets is that the solar system is young.”
No. Making the solar system young does not solve this (non)issue. Apart from requiring physics (the kind that allows our digital watches to run, mobile phones and car GPS’s to work) to be badly broken (we would have notice d by now if physics was that badly wrong), it explains nothing about comets that we would like to know. Why is the median age of Jupiter family comets 300,000 years, (not possible in a 6-10,000 year old solar system) and where do the nearly exhausted comets come from if the solar system is much younger than the median comet lifetime? Why are there 2:3 and other resonances in the Kuiper belt, resonances that will take millions of years to form? If the solar syetm is only 6-10,000 years old, why are comets in the inner solar system at all (and why do comets have the chemical composition of Kuiper Belt objects?)
There are a number of ways we can resolve the comet “problem”. Better estimates of Kuiper belt objects may show there are enough objects, other parts of the Kuiper Belt may supply comets, comet fragmentation (as seen with 73P/Schwassmann-Wachmann 3), as the objects move from the Kuiper Belt to the inner solar system, may provide more objects. There are a number of different ways which we can resolve this, none of which break normal physics, and you can bet that astronomers will investigate them.
Now, let’s have a look at how science operates. The Kuiper belt was a prediction bsed on our knowledge of comets, and that prediction was spectacularly confirmed. Instead of resting on their laurels, astronomers tried to estimate the numbers of Kuiper Belt objects, to see if it fit with their theories. Despite early agreement, they kept on refining their estimates. And when their estimates seemed problematical, did they hide them? No, they are published in open forums so that people can understand and work on the problem.
On the other hand, creationists only prediction was that the Kupier Belt was a figment of “evolutionists” imagination, when found, they did nothing but carp about it. Creationism has yet to give up on any of its theories, does no original work, and basically acts as a reaction to the findings of researchers.
Whatever the resolution to the Kuiper Belt conundrum, you can bet it will be scientists, not creationists, who will work it out Cand that creationists won’t like the answers)
 It doesn’t actually boil, but rather sublimes, vigorously.
 “soon” involving hundreds of person hours, years of patient watching and poring over plates and digital media, but “soon” in the context of how long it took to discover Pluto, for example.
Wednesday, May 06, 2009
Oh well, tomorrow morning may be clear, there will still be plenty of Aquairds then according to the meteor flux estimator.
Tuesday, May 05, 2009
Eta Aquarids, Tuesday 6 May 2009.
The maximum of the Eta Aquarid meteor shower occurs on the morning of May 6th. This is a fairly reliable shower or modest numbers. This year it has a predicted Zenithal Hourly Rate of 85, which for Australians, as the radiant never gets very high above the horizon, translates to a rate for around a meteor every 3 minutes or so.
The sky will be fairly Moon free this year, so viewing conditions should be good. The Meteor radiant (the place where they appear to come from in the sky) rises around 2:00 am, and best viewing time is between 4:00 am and 5:00 am.
The sky will look particularly nice, With Scorpio arcing above, and the radiant being between the glowing lamps of Venus and Jupiter. You might even see some satellites. So it's worth getting up and having a look.
Monday, May 04, 2009
Another Go at Saturn
I'm not having much luck imaging Saturn. After some weeks waiting, I had a nice calm (apparently), cool night, no cloud, I cooled the scope down a good hour beforehand and Saturn was near the Zenith. STILL the image bounced all over the place. My Moon shots weren't sterling either. At least I'm improving. I'm using a Philips ToUCam at 320x240 (left) and 640x480 (right) mode with Don the 8" reflector. I used a faster shutter speed and lower frame rate, and I think things came out a little better than before. One day I'll get a decent image.
Sunday, May 03, 2009
Carnival of Space #101 is here.
Labels: carnival of space
Cosmic Diary - Other Planets in Our Galaxy
"Are we alone in the Universe?" is a question we all wonder. We now know that there are no other planets like the Earth in our Solar System, so astronomers have extended their search to stars other than the Sun. These planets are called exoplanets.
Labels: International Year of Astronomy
Saturday, May 02, 2009
Images from the Occultation of Venus, April, 22 2009
Back in April 22, the Moon was pretty close to Venus from here in Australia, but in America the crescent Moon went in front of crescent Venus, a truly amazing sight. The YouTube Video embedded is from Kritirichards, using a a 70CM telescope in south central New Mexico (the visible crescent is Venus, not the moon). There is also a series of amazing videos at Astrophoto, as well as some great still images. Astroprof has some good images too, as does mom is a verb. Finally, there is an online article from Sky&Telescope about the occultation.
A Non-opposable Anniversary Missed
Friday, May 01, 2009
The Moon and the Beehive, 1 May 2009
Tonight, Friday May 1, the Moon will be very close to the Beehive cluster. Well worth a look and lovely in binoculars.