Planetarium at sea

I have just discovered that the Queen Mary II cruise ship has a planetarium on board. How cool is that?! It also doubles as a cinema/lecture hall. It apparently uses DigialSky and SkyVision to display 3D planetarium shows to the people on board. This is the system used in Western Australia's SciTech planetarium. I must admit that I am just a bit jealous of all this fancy stuff.

Posted in astro blog by Stuart on Monday 31st Jan 2005 (00:18 UTC) | Permalink

Einstein Questionnaire

While browsing some of WarickWarwick University's physics blogs, I found an Einstein questionnaire which seems to be part of a final year project. Hopefully, after the amount of exposure that Einstein has had in the last few weeks, most people could now get quite a few of these questions right. Watch out for Einstein fatigue disorder coming soon.

Posted in astro blog by Stuart on Sunday 30th Jan 2005 (16:08 UTC) | Permalink

Poetry of the Universe

The British Association (BA) have launched a poetry competition to promote Einstein year. It was launched at the Chilbolton Observatory by projecting a poem onto a radio telescope. They have got some astronomy celebrities (?!?) to write some poems to start the ball rolling. The celebrity poems aren't that good; Monica Grady really should stick to the day job ;-) If you can do better (surely anyone could) send in an entry.

Posted in astro blog by Stuart on Sunday 23rd Jan 2005 (01:07 UTC) | Permalink

An Opportunity to explore

The Opportunity rover has been exploring Mars for around one Earth year. That is incredibly impressive when you realise that the two rovers - Spirit and Opportunity - were originally designed to explore for 90 days. NASA engineers usually build these things to last a bit longer than we are initially told as it looks good when you tell people it is working better than expected, but I'm sure they didn't really plan for it to work this long.

A couple of weeks ago, Opportunity drove to the the site where one of the lander's heatshields had landed. It took pictures of the twisted metal of the heatshield that was littering the surface. It also spotted an ancient metallic meteorite nearby which has been called Heat Shield Rock. It is pitted with holes and, according to the spectrometers, it is mostly made of iron and nickel. Opportunity will apparently travel to a circular feature called "Vostok" within the next week.

Posted in astro blog by Stuart on Saturday 22nd Jan 2005 (22:40 UTC) | Permalink

Space in school

What a week I have had. One of the local primary schools has been coordinating a space fortnight exhibition which I have helped to staff. It seems that they organise this sort of thing once a year and this year they had chosen a space theme. They make sure that there are lots of activities such as making a rocket, 3D glasses, moon rocks from PPARC etc. and then invite other schools from around Cheshire to attend for half a day each.

The inflatable planetarium has been up for the whole of the two weeks and we have given tours to probably well over 700 primary school kids. They have been good fun to do and my familiarity with the constellations has definitly improved; my arm can now point out most northern constellations all by itself! I have also tried to add some stories from cultures other than the Greeks and Romans to add some variety. My favourite of the last few days was the story told by Thebe Medupe in this month's New Scientist about the hunter and the three zebra.

We have also had use of the Faulkes telescopes in Hawaii and Australia which was absolutely amazing. The Faulkes telescopes are copies of the Liverpool Robotic Telescope and were built for use by school kids (and amateur astronomy groups) in the UK to use during the daytime. Obviously, when it is day the UK, it is night in Hawaii so it is possible to take images live. Apart from the fact that last week was cloudy on Hawaii, we have managed to get some clear sessions (the aim was to do two half hour sessions per day) and take some really great images of Saturn, Jupiter, M82, M42, and quite a few other Messier and NGC objects. We even got to be the first people (other than the FT team) to use the Australia telescope which was pretty cool. As I said, the pictures were great but unfortunately I can't post them here as I haven't got copyright clearance - pity.

There were some great questions from some of the kids that attended. We managed to answer most of the questions but I went blank when one boy asked me how big the Sun was (about 1.4 million km which I managed to work out later). Doh! Still it was a great, if tiring, week.

Posted in astro blog by Stuart on Saturday 22nd Jan 2005 (19:06 UTC) | Permalink

Candles in microgravity

What happens to a candle burning in microgravity, say aboard the International Space Station (ISS)? On the Earth, the flame 'points' upwards because the hotter, less dense combustion products in the flame rise. Fresh oxygen is then drawn in at the bottom of the flame keeping the process going. In microgravity, things are a bit different. There is no buoyant convection so the products of the burning candle remain around the candle, slowly moving away in all directions. This also means that there is less draw on the oxygen which only gets to the flame by molecular diffusion. This is a slower process so it is quite possible for the flame to die out.

Are the flames really spherical and self-extinguishing? Back in 1996, investigators from NASA Lewis performed 79 candle burns in an experiment aboard the MIR space station. What they found was that the candles didn't quite go out, as had been expected, but showed "spontaneous and prolonged flame oscillations" near extinction. Flames in microgravity are pretty strange.

Posted in astro blog by Stuart on Saturday 22nd Jan 2005 (17:49 UTC) | Permalink

Huygens Lands

It seems as though Huygens has landed successfully on the surface of Titan. There seem to be some issues with receiving data on one of the two data channels though. Although the 'A' channel doesn't seem to be transmitting, apparently the 'B' channel didn't lose a single packet of data. The data has yet to be processed so we should expect images later on tonight, possibly around 19:45 GMT, although as the press conference this afternoon started over 15 minutes late, it might be 20:00 GMT. The NASA TV footage has mostly worked although there are obviously bandwidth problems as so many people try to watch at the same time.

Posted in astro blog by Stuart on Friday 14th Jan 2005 (17:34 UTC) | Permalink

Huygens descent

This Friday, the Huygens lander begins descent onto Titan, one of the moons of Saturn. The craft wakes up at 5.44 (CET) and finally deploys its parachute at 10.10. During the descent, which will take around 137 minutes, the sensors will be operational. They will sample the atmosphere and take images of the surface. Touchdown occurs at 12.27 at about 5 metres per second. What it lands on is unknown. Will it splash, crash or squelch? Assuming it survives, it will keep collecting data until 14.37 when it can no longer see the Cassini craft. Finally at 15.07, Cassini sends the data back to Earth with its high-gain antenna. We will have to wait a full 67 minutes for the radio waves to get from Saturn back to the Earth; it takes some time even at the speed of light. Perhaps, at 16.14 you might see some celebrations on the webcam at ESA's Operations Centre.

Posted in astro blog by Stuart on Wednesday 12th Jan 2005 (19:47 UTC) | Permalink

Einstein Year - part 2

I think the Institute of Physics deserves some kind of award for the amount of publicity they have been getting for the World Year of Physics (known as Einstein Year in the UK). It seems as though Einstein has made it into the news (papers/TV/radio) every day since 1st January. We have had BMX stunts, a theory of relativity inpired ballet and an Einstein rap ("Yo yo yo! Give it up for the main man from da IoP"). I wonder if the IoP have a press release lined up for every week until the end of the year.

Posted in astro blog by Stuart on Wednesday 12th Jan 2005 (19:33 UTC) | Permalink

Shrinking Earth

According to NASA, it seems the earthquake which occured when the edge of the Indian plate slid under part of the Burma plate on boxing day and caused such devastation around the Indian Ocean has shortened the Earth's day by 2.68 microseconds and moved the north pole by 2.5 centimetres. That may not sound like a lot, but just think of how much rock had to move in order for that to happen.

The two plates in question sit next to each other, gradually pushing up against each other as movements of other plates around them force them together. Over long periods of time this causes stresses to develop along the edge (also known as the interface). An earthquake is often the result of these stresses finally being released in one, or more often a series of, violent plate movements. Thankfully, events of this magnitude are very rare.

Posted in astro blog by Megan on Monday 10th Jan 2005 (22:48 UTC) | Permalink

Galileo lecture

Dr. Allan Chapman, a history of science scholar - especially astronomy - from Oxford, is giving a lecture to the Macclesfield Astronomical Society this coming Saturday. The talk is titled "Galileo - the Martyr who brought his own Firewood" and starts at 8pm in the lecture room at Jodrell Bank. It should be good as Dr. Chapman is an animated and eloquent speaker who can talk for a full lecture without stopping to look at any notes. I first saw him doing the Channel 4 programme Gods in the Sky which, perhaps suprisingly these days, had virtually no computer graphics. Oxford University has a webcast of a lecture he gave on "Science at Oxford in the 17th Century" so you can get an idea of his lecture style.

Posted in astro blog by Stuart on Thursday 06th Jan 2005 (11:40 UTC) | Permalink

First light for Swift

The Swift mission, launched back in November last year, had first light just before Christmas. One of their first images was of Cassiopeia A, a remnant of a supernovae that happened around 1680. Radio astronomers know Cassiopeia A (or Cas A to its friends) as the brightest source in the sky outside of the solar system. However this is just a calibration image as the missions primary goal is to observe gamma ray bursts (GRB).

GRBs are thought to be the most powerful explosions known in the universe although they only last a short time. Rapid observations are essential, once a burst happens, if astrophysicists are to work out the physics behind the processes that causes them. One of the instruments on board, the XRT, obtained an accurate position, spectrum and decay light curve of a gamma-ray burst 'afterglow' for the first time on 23 December.

Posted in astro blog by Stuart on Thursday 06th Jan 2005 (11:10 UTC) | Permalink

A new calendar?

With a new year how about a new calendar? No, not a nice new HST images calendar from Amazon but an entirely new system of dates. A strange suggestion I know but it was discussed in an article on EurekaAlert just before Christmas.

It seems that Prof. Richard Henry has proposed a new system that would mean that month days would always fall on the same day of the week. So if your birthday falls on a Tuesday it will always fall on a Tuesday. My immediate thought is to feel sorry for those born during the week as you wouldn't get a weekend birthday again. The point of all this is that we would never need to buy a new calendar again as they would remain the same from year to year.

If it is such a great system why has nobody done this before? The answer lies in the details. The system will have either 30 or 31 days in every calendar month and leap years will be abolished. There are 365.242199 days in a year so this system - like all the others - needs to add extra days every so often to stop the calendar getting out of sync with the seasons. To do this, Prof. Henry adds a short, extra month (currently called Newton) every five or six years. Here we run into practical problems as this means every year will not be identical as suggested. Prof. Henry's hope is that we will all be given the whole of Newton as a holiday, but I don't think this is very realistic? The other problems are practical ones related to birthdays for those born during Newton or those whose birth dates would no longer exist.

What about the practical implemenation of this new system? Every date function on every computer around the world will need to use a large lookup table of years to find out when to include the extra month and to work out the time between two dates. At the moment there are well defined formulae to work out the number of days in a year so to me this is a step backwards. When changing our calendar we need to stop to think if we will really benefit so much from the change. This calendar doesn't really get rid of the problems we have with the current calendar such as the unequal length of the months and the addition of leap days.

There is also a suggestion that we adopt Universal Time (UT) as the standard for our clocks. This would remove the need to work out time differences between different locations around the world; if it was 10 am in Manchester it would be 10 am in Tokyo. This may seem great but is only of benefit to those that work across time zones and most of them (e.g. astronomers) use UT already. For most practical purposes it would cause confusion over when to go to sleep or wake up; if you went to a different part of the world you would have to find out what the local working hours were - New York might be 14:00 until 22:00 for instance.

Calendars should only be changed when they produce a significant improvement over the existing system. What next, a calendar based on Sidereal Time? Actually, come to think of it, I wouldn't mind a wrist watch that shows sidereal time as well as local time.

Posted in astro blog by Stuart on Wednesday 05th Jan 2005 (17:55 UTC) | Permalink
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