Category Archives: science

Free space images from the web

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I just looked at a few sites providing space related images for download. All images – except the logo’s from these three sites are freely useable for non-commercial purposes, including personal web sites – of course with a clear attribution of the source.

The three sites I looked up here are

NASA (of course)for general space travel and some astronomical images.

The Spitzer Space Telescope for images taken in infrared

and of course The Hubble Space Telescope with some of the most stunning astronomical images made

If you like images, maybe using them part of your web pages these are three very good sources.

Do not forget that many observatories and universities have images available. These include very old images from the classical telescopes in the world. I believe there is a project to scan all those ancient images before they are lost forever due to the deterioration pf the photographic material.

The old images *could* become important  for detecting transient events or variable phenomena, like recurring nova outbursts, so we can not afford to lose these images.

Planets detected around Epsilon Eridani

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This is exciting for me as  a science fiction fan and as someone interested in space science in general.

Epsilon Eridani is a star a bit smaller than our own Sun – and quite young – only 800 million years old, located about 10.5 light years away.  Recently the Spitzer Telescope has detected a double asteroid belt around the star. The inner belt is located at a distance similar to the asteroid belt in our own solar system. Furthermore what looks like a cometary ring similar to the Kuyper Belt and indications of a planet at a distance similar to Jupiter’s. The Epsilon Eridani system looks more and more like our own solar system.

For more information take a look at these websites :

From the Spitzer Telescope site

From Discover Magazine

In the 1960’s I remember the scientific programs on the radio talking about SETI (Search for Extra Terrestrial Intelligence) and mentioning this star as a likely candidate. At the time the young age of the system was not known, but it gave rise to the use of many science fiction writers using it as a home for intelligence.

In “Star Trek” the Mr. Spock’s home world Vulcan is located in the Epsilon Eridani system. and in “Babylon 5” the space station is in orbit around a planet in the same system.

Of course the star is featured in many other science fiction stories, too many to mention here.

Interesting stuff…

Fantasticon2008, Copenhagen, 26 – 27 April

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This is a small Danish convention with a few hundred people attending. Only foreign Guest was Norman Spinrad. The con was held in the “Vanloese Kulturhus” (cultural house) in nice large rooms and a terrace. Even the weather cooperated and we could sit outside chatting along between the programmed events. I arrived there after a long (12 hour) drive and a few hours of sleep.

On Saturday I went to the interview with Niels Brunse who has translated a large amount of English language books into Danish, and also written stories of his own. He was, among other subjects, talking about the difficulty of making a good translation, something I can relate to in a limited capacity, having attempted translation in both directions between Danish and English. Some elegant words or phrases in one language translate *very* poorly into the other.

Sunday had a surprise guest speaker, the Danish physicist Holger Bech Nielsen, giving a presentation of his version of the “theory of everything” : “Random Dynamics”. He is a *very* lively lecturer, and it is always fun to see him, his enthusiasm for the subject is just radiating from him. This was the first time I saw him “live”, the other times were just on television.

Arthur C. Clarke :

For me the best part of the programme on Sunday was the panel discussion about Arthur C. Clarke, the panel consisting of 3 Danish fans and the guest speaker Norman Spinrad. Spinrad had sopme cooperation with Clarke in the 1960’s and could tell us that the final scene of the movie “2001 – A Space Odyssey” was in fact not the one we saw in the movie. Clarke had envisioned a scene with very beautiful aliens, but it was not technically possible to do to his satisfaction – meaning the scene had to be rewritten.

Clarke’s relatively optimistic view of the future has by some been regarded as naive, but it most probably is an expression of his dream about the future.

Finally there was a discussion of Clarke’s unusual combination of hard science fiction and the “mystical” (for lack of a better word), something very prominent in “2001”, but it is in much of his other work.

Of course, you cannot mention Arthur C. Clarke without talking about his strong influence on science and technology (as well as science fiction), interesting to see how many of his early thoughts have come true already.

All in all a very nice week end , I will try to make it again next year.

More real life space communications (2)

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The Soyuz spacecraft has successfully docked to the ISS today.

Yesterday I listened for radio communications from the Soyuz, and was rewarded with hearing a few exchanges in Russian. They were likely talking to the ground station in Moscow. The frequency for Soyuz is 121.750 MHz, if any of you should have a scanner receiver. The signal was quite strong, even with a wrong sized antenna, so it should not be too difficult to hear.

Good hunting if you try – They will probably be radio-active for a day or two when they leave the ISS and return to Earth.

In the meantime , if you are in Europe, you can listen for the ISS , in the rare cases when they talk back to Moscow, on the frequency 143.625 MHz.

More real life space communications

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When STS122 had just been launched, I went out to see if I could spot it and the ISS. The ISS arrived right on time and was *very* bright and easy to see (I missed the Shuttle, though). I had also brought my scanner radio receiver with me, and just before the ISS went into the Earth’s shadow , I heard a carrier wave for a few seconds , followed by [chorosho] (Russian for “good”) and a few more words in Russian, since they were communicating with a ground station in Russia.

In the first few orbits after launch of the space shuttle(s) and the last few orbits before the re-entry (landing) the shuttle uses the frequency 259.700 MHz (AM) for clear voice communications.

A few weeks later, when the STS-123 was launched, I joined a group listening for the Shuttle “Endeavour”. but since the high power (10 Watts) transmitter of the spacecraft was out, they were only transmitting with the low power (0.25 watts) transmitter. with my simple antenna and a long cable in to the receiver the signal was lost here, but a few other people around in Europe did hear them.

Since then I have had a preamplifier mounted at the antenna , so the loss in the cable has been compensated.

In the last few orbits before re-entry I listened for Endavour again – and even with their low power transmitter it was audible here. Signals were weak and noisy, but a few sentences were clearly heard here. Next time I will have to do some recordings.

Arthur C. Clarke died at 90

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I know this happened last week, but the preparations for going to the Eastercon/Orbital2008 have overshadowed most other things. See also previous post.

I first became aware of Atrhur C. Clarke through the movie/novel “2001 – A Space Oddyssey” which made a considreable impression on my young self.

One of my favorite longer stories by Clarke is “Rendezvous With Rama”.

I have on my shelf a brick of a book with about 100 short stories by Clarke , I think I will slowly work my way through those.

At the convention I found a signed copy of “Tales From the White Hart”, and despite the (understandably rather high) price I just had to get it. Should read the short stories in that one, too.

I see Arthur C. Clark as one of the giants in science fiction, and a very influential science writer – one of the few science fiction writers with a scientific writer’s background.

It was good to see a last minute addition to the Eastercon programme of a panel discussion about Clarke’s influence in science as well as science fiction. On top of that, one of the panelists had been the secretary for Arthur C. Clarke for about a year, and he could bring light on theless public sides of the author. Nicely done.

He will be missed in the scifi community.

Real Life Space Communications

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As we all know, a lot of science fiction involves space travel. We sometimes tend to forget that real life space travel already takes place, albeit on a somewhat limited scale.

This week end I did a little listening to spacecrafts on the radio. You may not believe it, but space communications is not as difficult as many people would think.

I was finding out when the ISS came over the horizon here and started listening to a relay station for ham (amateur) radio situated on the ISS. If there is not any spacewalks going on, the relay station is active listening on the 435MHz (uplink) band (70cm) and transmitting on the 145MHz (downlink) band (2m).
The downlink on 145.800MHz was clearly audible with a scanner radio and a simple whip antenna, as soon as I went out on the balcony of my apartment. On average the period with audible signals is 10 minutes per pass, shorter when the pass is near the horizon and longer when the station comes over my head.

Many years ago I sometimes set my receiver to 143.625MHz in order to listen for the MIR space station (yes – the Russian one), and have heard that one talking to the Earth station.

On some occasions it is possible to have a contact with one of the astronauts on the ISS, if they have the free time and interest. Almost all the astronauts have the license to transmit from up there.

In fact, the radio hams have several satellite relays orbiting the Earth, giving them the opportunity to try out space communications. Most of those are in a low Earth orbit, and therefore they are only useable for a short time. Some have a very elongated orbit (not really any right now), giving the opportunity for longer communication periods.

Most of us know about TV and communications satellites in the geostationary orbit (the satellite follows the Earth’s rotation and seems to be stationary over a certain point on the Earth). The dream of some radio hams is getting their satellite out there, giving 24/7 communications.

Just a dream … but maybe not any longer. There seems to be negociations going on between the AMSAT (Amateur Satellite) organisation and Inmarsat, about getting a lift with one of their satellites, and even sharing the power from the solar panels. We never know if this will come true, but I sure hope so.

Do not forget that the Space Station is a rather big satellite and is very easy to see when above the horizon. So – even if you cannot receive it on the radio you can go outside and observe a *real life* manned spacecraft. if you want to know when it can be observed at your place , go to Heavens Above and find out. it is a good idea to register, so you can have your location recognised when you log on.

Comet hunt …. Success tonight.

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After what feels like an eternity of cloudy weather I got to see comet Holmes.

A bit of clear sky appeared , and the comet was just visible to the unaided eye here (the sky is heavily light polluted where I live).

Without any optical instruments it looks like a star to me – maybe it would be fuzzy in a darker sky.

Using a pair of binoculars at 15x magnification the comet is much like the pictures as seen here , with the exception of the faint green haze outside the brighter disk.

It looked bigger than I expected, and I noticed thet in order to get the most from the view, I had to use “averted vision” that is focusing the view a bit away from the comet. The brighter core is a little elliptic looking and a little offset from the centre of the disk.

If you have a pair of binoculars, you should go out and take a look. The Sky and Telescope link above gives you what you need to find the comet.

This is the third comet I have seen, only Hale-Bopp in April 1997 was bright enough to be clearly seen in the heavily light polluted skies of the western Netherlands, but this unexpected view is much better with a pair of binoculars , or better a telescope using a not too high magnification 20 – 50x should be fine.

Good luck comet hunting.

Comet bursting into the sky.

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Two days ago Comet 17P/Holmes was an insignificant piece of ice barely visible in amateur telescopes under dark skies.

Yesterday all that changed . If you have a clear sky, take a look in the constellation Perseus, there you will find an extra “fuzzy star” – visible to the unaided eye. With a visual magnitude og between 2.5 and 3 it should be about as strong as the stars in the “Big Dipper”, “The Plough”, “The big Wagon” or whatever you may call the most well known constellation in the Northern sky. The increase in brightness is about a million times in about 24 hours – quite amazing.

Take a look at Spaceweather.com for more information – and a star map to find the comet, and Cometography for a bit of history of this comet.

Stop Press: Latest estimates are now magnitude 2 …. even brighter … so the outburst is still in progress.

Here’s hoping for a little clear sky at my place i The Netherlands …

Good luck with comet hunting.

Radio Astronomy and SETI

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On 11 october a new radio telescope started operation. The Allen Telescope Array (ATA) in Hat Creek, CA is planned to be extended to an array of 350 dish antennas with a diameter of 6m (20ft) The inauguration was done with the first 42 of these dishes.

The ATA is built to do simultaneous radio astronmical observations and SETI work.

More detail can be found at the website for the SETI institute ATA ppress release.

I am quite excited, since the data collected from the ATA is *much* more than from traditional single dish telescopes , and more than will come from the VLA (Very Large Array) – and for a cost much loser than for older (traditional) radio telescopes.

For more about SETI (Search for ExtraTerrestrial Intelligence), take a look at at the websites :

SETI Institute

SETI League

SETI@home