# A mysterious signal from space

It's late in the evening when your friend Mike, a brilliant astronomy student, points his radio telescope to Omega Centauri, a large globular cluster distant almost 16000 light-years from the Earth.
After inspecting the sky for a few minutes, you notice a strange signal coming from an outer star. It's a 177 GHz microwave radiation with a variable amplitude.
Mike is amazed, he has never seen a signal like it, so he decides to analyze it.
Immediately he notices that the wave conveys a sort of message; then he observes that this message is periodic, so he is able to extrapolate this binary sequence:

00000000101010100000000101000001010000001000100010001001000101010101010101000000000000000000000000000000111000000000000001111100000000000000010010000000000000100011000000000000110100100000000000011111110000000000000000000000000000000000000000000000100000000001000000000000000010000000000101000000000100000111111100111111100000000000000000000001010000000000000000101000100000001000011111110011111110000000000000000000000000101000000110000000001000000111100001001110010111111000011111110011111100000011100000111100000001110000001100000001111100011111100001101011001011010000100100100100001000010010010010000100000000000001000010000000000000000000000011110111100000100001111011110101000000111101111010000000011110111100000000000000000000000000000000000000000000000000000000000000000


Now, Mike is at a dead end, he has no idea of how to interpret that signal. Does it really contain a message? Is it artificial or natural? Aliens are communicating?

Help Mike finding all the information included in the mysterious signal.

• 779 bits with huge stretches of zeros. I'm not sure what to make of this. – Bob May 16 '15 at 14:53
• 779 (taking @Bob's word for that) is 19 times 41, but writing them out in a rectangle doesn't seem to turn the 1's into a picture or anything... – Rand al'Thor May 16 '15 at 15:14
• New puzzle: what's the significance of the binary code in leoll2's profile? – Rand al'Thor May 16 '15 at 20:29
• @randal'thor finally someone noticed it! And it's not random! – leoll2 May 17 '15 at 6:32
• @leoll2 Done! I hadn't realised there was a bigger picture until I went to save the image, but now I see you've updated your profile page ;-) Now you can watch your number of profile views skyrocketing! – Rand al'Thor May 17 '15 at 10:22

Arranged correctly the bits form a 19 by 41 grid very similar to the Arecibo message.

Based on the pattern used in that message, this message contains the following information.

Their body chemistry is composed of the following elements:

Hydrogen Lithium Oxygen Aluminium Chromium Iron Gallium

Probably in these compounds...

4101000 Lithium Aluminium Hydride
2040100 Chromic Acid
3030001 Gallium Hydroxide
0000010 Iron

The aliens have two of what might be arms, three legs (I hope they're legs), and two horns, large ears or antennae.

They might have considerable sexual dimorphism or fly about in 50s style rocket ships.

They live in a binary system on the third rock from their suns. The closest planet in the system to the suns is the largest.

• Good job! By the way, their ship resembles the USS Enterprise (Star Trek), but that doesn't matter :-) – leoll2 May 16 '15 at 15:38
• Picture please? @leoll2 Great puzzle! I tried 41 by 19, and then gave up without trying 19 by 41 :-( – Rand al'Thor May 16 '15 at 15:44

Just for clarity, this is a picture of the solution (the bits arranged in a 41x19 grid).

As you can see, it resembles the Arecibo message.