This is a call for a fun scientific challenge. Suppose a telescope on Earth receives a series of pulses from a fixed, unresolved source beyond the solar system. The source is a star about 50 light years from Earth. The pulses are in the form of short/long signals and they are received in a very narrow band around an electromagnetic frequency of 452.12919 MHz. A computer algorithm identifies the artificial nature of the pulses. It turns out the pulses carry a message. The pulses signify binary digits. Suppose further that you were, by whatsoever reason, put in charge of decoding this message. If you successfully decrypted the message, you should be able to answer the following questions: 1. What is the typical body height of our interstellar counterparts? 2. What is their typical lifetime? 3. What is the scale of the devices they used to submit their message? 4. Since when have they been communicating interstellar? 5. What kind of object do they live on? 6. How old is their stellar system? These are the rules. 1. No restrictions on collaborations. 2. Open discussion (social networks etc.) of possible solutions strongly encouraged. 3. 3 hints to the solutions can be offered as per request. 4. Send your solutions to me via e-mail (heller@mps.mpg.de), twitter (@DrReneHeller) or facebook (DrReneHeller). Human-readable format and the format of the message are allowed. 5. On 3 June 2016, a list of the successful SETI crackers (in chronological order) will be released. UPDATE 6 May 2016: This call generated an e-mail storm on me. I kindly ask you for your understanding that I will restrict replies via e-mail to a minimum. Correct submissions will, of course, be acknowledged. UPDATE 7 May 2016 E-mail traffic is still overwhelming. From now on, I will not be able to give additional hints and will only respond to correct (or very creative) solutions via e-mail in English or German. These are the three hints mentioned in the rules. 1. The number of bits (0 or 1) is 1902341. This is a product o the prime numbers 7, 359, and 757. 2. The message is the black/white pixel map of an image. 3. The image shows 7 pictures or pages. As a sanity check, you will be able to recover the duration of the travel time (50 years) from page 4.