Iridium flares December 31, 2003
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The night sky is full of magnificent natural sights, but there are also quite a few interesting man-made objects. When I was young, many of the orbiting satellites were clearly visible to the naked eye and some, like the Echo series of satellites, were very bright. The Echo satellites were no more than balloons which could be used to reflect radio signals but, owing to their large size and low orbits, they appeared as brilliant objects which raced across the sky. At one time there were so many low-orbit satellites that you could just stand under the night sky and wait for one to appear.

Advances in technology have reduced the number of visible objects; most low-orbit satellites are too small to be visible, while the large communication satellites now hang in stationary orbit some 36,000 km above the surface of the earth, too high to be seen with the naked eye.

Another space fan in the ChessBase team, Jeroen van den Belt, is experimenting with plotting the position of the International Space Station on our Playchess.com server globe display. Maybe soon you will be able to locate your opponent on the globe and check when the ISS is visible in your current location.

Of the objects which are actually visible, the ISS (International Space Station) is worth watching out for. It looks like a bright star, but has a fairly low orbit and so moves at a fair pace across the sky. You might also be able to spot some pieces of space junk, such as spent booster rockets, which have ended up orbiting the Earth. Although there is no doubt that today’s technology is far superior to that of the 1960s, I still miss the simple pleasure of lying on my back under a starry sky and watching the moving lights that indicated man’s presence in space.

However, these days there is one sight which is so spectacular that nobody should go through life without having seen it. Imagine looking up at the night sky. Suddenly you see a faint moving point. You assume, correctly, that it is a satellite. Then, unexpectedly, the point starts to become brighter. In a matter of seconds it is as bright as the brightest star, but it doesn’t stop there. The light becomes more and more intense until it is a dazzling point far brighter that the brightest planet. It remains at maximum intensity for about five seconds and then fades again.

Doubtless this unusual phenomenon, called an ‘Iridium flare’, has been the cause of many UFO reports, but the explanation is more prosaic. Its cause lies in the network of 66 Iridium satellites which form a communications network covering the whole planet. You can buy a satellite phone (like the one on the right) and make use of it yourself, although this might make a hole in your bank account. Find out more at Iridium site.

The satellites themselves, which orbit about 800 km up, are usually a little too faint to be seen with the naked eye, but each one is equipped with three antennas. These antennas are flat surfaces covered with highly reflective material. When the sun shines on the satellite and the orientation of an antenna is correct, it acts as a mirror casting a beam of reflected sunlight onto the surface of the earth. It is the two antennas at the left which act as mirrors and not the solar panels on the right.

As the satellite orbits the Earth, the beam traces a path across the surface of the planet. When you are standing directly in this path, you first see a relatively faint reflection as the edge of the beam reaches your location. The reflection becomes brighter until the beam is centered on you, and then fades away again as the beam moves on from you across the planet. The beam is about 40 km wide on the surface of the Earth, but for the most spectacular results you should be within 3 km of the centre of the beam. Given the size of Earth, it might seem very unlikely that a beam would pass within a few kilometres of your location, but there are so many Iridium satellites and they orbit the Earth so frequently that you can expect at least one good flare each week.

In order to find out when to expect a flare (and where to look for it in the sky) go to the excellent Heavens Above web site, which will do all the calculations for you. If you live in a city you can choose it from a list, but otherwise you will need to know your exact geographical coordinates (either consult a map, or use a GPS receiver).

The Heavens Above site will calculate which Iridium flares are visible for the next seven days and you can print this list out. Anything of magnitude -7 or brighter will be spectacular (the smaller the number, the brighter the object, so -8 is brighter than -7). When observing a flare, I have found it helpful to have an accurate clock (use either a radio-controlled clock or a GPS receiver). Heavens Above gives the time accurate to the second and you should start observing about 30 seconds before the indicated time. You really can’t miss a flare if you are looking even vaguely in the right direction.

There are quite a few amateur photographs of Iridium flares on the web. The long exposure turns the flare into a streak, but this image clearly shows how the satellite brightens and then fades away again as it crosses the sky.

The above is an Iridium flare, shown on the Prime Focus website. Here's another spectacular one. The satellite grows in brightness by a factor of 10,000 in less than half a minute. Many more excellent flare pictures can be found at Timo Leponiemi's "Satelliitit" site.

I am sure that if you take a good shot of an Iridium flare, Frederic will put it up on the ChessBase website.

P.S. I know all this doesn’t have anything to do with chess, but there is so little going on in the chess world at the moment that there should be plenty of spare time for watching Iridium flares.

John Nunn

Catching a flare

Following John's advice we went to the Heavens Above site, entered our geo coordinates (which we took from our own "Personal info" on the Playchess.com site) and asked for flares for the next week. One was good and we decided to catch it.

The table above is tells us that on December 29th at 16:35:34 hours an Iridium flare would appear at an altitude of 31° in a 282° WNW direction. The flare will appear as a minus six object at maximum intensity – it would be minus seven if we travelled 9.8 km west to the centre of the flare path. Click on the links in the table for more information.

Using a Canon digital camera and a 200" telephoto lense we were able to take the above picture. We did it without a tripod, and the curve in the path is probably due to hand movement during the exposure (about 1/15th of a second).

Back to chess

But we do want to include a little chess. Yesterday's column brought us a large number of letters, one of which contained some criticism. We do not want to keep it from you: Robin Masur of Switzerland wrote:

Thank you very much for this interesting story about the unknown Saavedra. I am very fond of Chessbase articles in general, and if I send you now this little message, this is just because one sentence made me uneasy, even angry: "Saavedra had never before stood in the limelight. Apart from finding this move, 6.c8R!, he has done nothing worthy of mention in the chess world. As Tim Krabbé writes: 'Saavedra was a mediocre chess player whose name, through chance, will live forever in chess literature.' If it wasn't for this move the name would have been completely unknown today."

I find it very insulting to treat this poor Saavedra with such contempt "A mediocre chess player" indeed! Why does Tim Krabbé not uses "modest" instead of "mediocre" which is certainly a word more accurate? The use of the word "chance" make me angry too, whereas "passion" would have been more rightful. I thank the late Saavedra all my heart, him who reminds us that a modest chess player sometimes can matches our proudly half-gods GM chess players.

To this we would like to say that Fernando Saavedra achieved chess immortality by finding a single two-move combination. There must have been hundreds of contemporaries who dedicated their lives to the game, lived on the verge of starvation while creating eternal masterpieces, jewel after jewel, without entering the chess annals or encyclopedias. So we feel that Saavedra actually got a pretty good deal, and we don't need to glorify him even more. Incidentally he never tried to claim authorship for the study or idea, which were initially attributed to Barbier. Saavedra was saved from oblivion by the editor of another newspaper, the Falkirk Herald. His name was Neilson and he became obsessed by the 6.c8R ídea, publishing it repeatedly in his own column. He showed the position to Lasker, who mentioned it in a lecture. This was subsequently published in the BCM, which used Saavedra's name. That was when he became eternally famous.

We take up the subject one more time, with another study inspired by Saavedra's move.

V. and M. Platov, Deutsche Schachzeitung 1908

White to play and win

The solution is 1.Kb4! [1.h6? Rf6 2.h7 Rh6 is a draw, as is 1.Kd4 Rf5 2.c6 Rxh5] 1...Rf5! [not 1...Rb1+? 2.Kc4! (2.Ka5? Rh1=) 2...Rc1+ 3.Kd5 Rd1+ 4.Ke6+-; and not 1...Rh1? 2.Be5+ Ka2 3.c6+-] 2.c6 [2.h6? Rh5 3.Bf4 Rh4 4.c6 Rxf4+ 5.Kc5 Rf7 6.Kb6 Rh7 7.c7 Rxh6+=] 2...Rxh5 3.c7 Rh4+ 4.Kb5 [4.Kc5 Rxh2=] 4...Rh5+ 5.Kb6 Rh6+ 6.Bd6! Rxd6+ Saavedra! 7.Kb5 [7.Kc5 Rd1=] 7...Rd5+ 8.Kb4 Rd4+ 9.Kb3 Rd3+ 10.Kc2 Rd4 11.c8R! Ra4 12.Kb3 1-0.

The Platov brothers, Vasily (1881-1952) and Mikhail Platov (1883-1938), were Latvian endgame study experts. They started composing independently but after 1905 started working as a team. The older brother Vasily was more creative, but he worked best when supported by his brother. Together they became pioneers of the emerging art form of endgame studys (together with Troitsky, Kubbel and Rinck). Here is one of their more famous works:

V. and M. Platov, Rigaer Tageblatt 1905

White to play and draw

To solve this study you have to neutralise the hostile queen. The way this is done is elegant and humorous at the same time.

Click here to see the solutions to all puzzles.

The page contains all the unsolved problems. It includes a link to a Javascript board on which you can can replay the moves of each solution and download the positions. On the Javascript page you will find all the positions quoted in our 2003 Christmas Puzzle section, including the ones for which solutions are already given in the text.

Tommy's Christmas Repton

Martin Leung of Irvine, California wrote: "Thanks for intoducing me to the game Repton! I am on Level 6 and I'm addicted. I usually play other games like Starcraft or Warcraft III but now I'm spending more time playing Repton. Its a simple and fun game. In fact, it's one of the simplest games I have ever played, but it takes a lot of calculation to solve it. It's quite a shock when you're moving fast and you dont notice a rock, and suddenly the falling rock sound plays, and a split second later you're 'dead'. Sometimes my hands sweat when I'm in difficult spots. And whoever came up with that Repton with a green face, must be really creative. Thanks a lot for sharing this game with chess fans! I have passed this game on to my friends, and they like it as well. Happy New Year!

Kerem Yunus Camsari of Ankara, Turkey: "This is just incredible! Repton mania! We were playing this kind of games when I was a kid! It's like 'sokoban' and some other superb PC games which are actually a bunch of bytes but they're full of joy and mystery indeed! I am curious too, about the fact that the time I've spent for each level was gradually getting smaller and smaller!... Maybe I am getting better! I've completed the first 6 levels and cannot wait for the upcoming level . And about the complaint of 'manipulation skills' that is right in a way. However, a little action makes the game adorable and forces the player to make some mistakes like enclosing some places etc. I don't think the Repton game should be of pure logic and mathematical sense. It's fun to see a monster, chasing you making funny movements, and It's even more fun to push a huge boulder onto it. I am happy with the game's action and puzzle balance. And please give us more puzzles and levels!!"

Screen seven

You can upgrade your Christmas Repton to screen seven by downloading the following file, repton1.rep (8537 bytes long). Save it in the subdirectory Christmas Repton\data\maps\, overwriting the previous repton1.rep file there.

• Download the seventh level of Repton

The new file contains seven of eight levels. The levels can be accessed either by solving the previous level or by entering the password you get when you solve it (click File – Enter password).

If you have not started to play the game yet you can download the whole thing (142 KB) and follow the instructions given at the bottom of our Chistmas Day page. Note that this contains all levels published so far, so you don't have to retrieve the above file to upgrade.

• Download Tommy's Christmas Repton here

The latest Repton game is available from the Superior Interactive site. Click on the logo on the right to download a trial version. For $19.95 you can get a key that upgrades it to the full version. You may also want to try the PDA and cell-phone versions of Repton from Masabi. The Superior site also has the games Galaforce and Ravenskull.

We will be providing new levels for Tommy's Christmas Repton on a daily basis until the end of our Christmas Puzzle week. Please make a note of the passwords, especially the last one you get. You can send them in, together with your comments, to take part in our Puzzle contest in which you can win some interesting prizes.

Superior has donated three dual prizes of Galaforce Worlds and Ravenskull
for the best solutions and comments to Tommy's Christmas Repton.