GLIESE 581d, Here I Come... At 7:00 PM, California time today (12:00 PM Sydney time on Friday, August 28), a large radio telescope near Canberra, Australia began transmitting into deep space a signal containing 25,880 text messages gathered by COSMOS Magazine (for its Hello From Earth campaign) earlier this month. The signal is headed for a star system known as Gliese 581, where a potential ocean-covered planet (known as Gliese 581d) could possibly be harboring life. The signal will take 20.3 light-years (119 trillion miles, or 192 trillion kilometers) to reach Gliese 581, meaning it should arrive at the star system around December of 2029, give or take a few months. If advanced alien life forms do detect and decipher our signal, we wouldn't get a response from them till as early as 2051.
The agency responsible for transmitting the signal was NASA...since the radio telescope [known as Deep Space Station 43 (or DSS-43), which is 70 meters—or 230 feet—in diameter] that was used is part of the worldwide Deep Space Network (DSN) that communicates with interplanetary probes such as Cassini, Dawn, Kepler and the New Horizons spacecraft. According to COSMOS Magazine, the messages were encoded into a binary format (by engineers at NASA's Jet Propulsion Laboratory in Pasadena, California) before being transmitted by the Canberra Deep Space Communications Complex at Tidbinbilla, Australia. They were sent at a 7.145 Gigahertz frequency at 18 kilowatts...meaning the signal is technically slightly more powerful than some of today’s best computer servers. However, the size of the 70-meter DSN telescope amplified the signal...making its strength the equivalent of using the transmitting power of 300 billion cell phones combined (or 300 gigawatts). The transmission will fly through the Gliese 581 star system two times over two hours...since the signal was relayed twice from DSS-43.
(I did the math, and if the two signals were sent into space exactly two hours apart from each other, then the first signal should be traveling around 1.3 billion miles—or 2.2 billion kilometers—ahead of the second one!)
With the technical aspects of this Blog now out of the way, all I can say about this campaign is that it’s pretty friggin’ cool! And very amusing too...but not in a good way. In terms of it being cool, Hello From Earth somewhat made up for me not being able to get my name on the Pluto-bound New Horizons probe 4 years ago. The opportunity this time around is actually a lot better. Even though my name (and the message I typed) is in the form of an encrypted radio signal and not imprinted on an actual object like a microchip or a compact disc, my name will reach interstellar space a whole lot faster (since it’s traveling at the speed of light) than on a robotic spacecraft using conventional rocket fuel; and the signal will last as long as outbound space probes such as New Horizons and the Pioneer and Voyager spacecraft possibly will. (Assuming, of course, none of these probes collide with an interstellar asteroid or something.) After the signal reaches Gliese 581d, it will still be strong enough to be detected by intelligent life forms up to 100 light-years from Earth. Despite diminishing in strength as time goes by, the artificial nature of this transmission should be detectable up to 10,000 light-years away, before the signal disappears completely. That’s what I call a long shelf life. However, this doesn’t mean that I still can't wait for the day NASA approves another robotic mission like New Horizons that will fly beyond our solar system.
Now...in terms of Hello From Earth being amusing, but not in a good way, if alien beings EVER DO detect and decipher this signal, and they actually speak um, English, then they will most likely be appalled by our transmission. Browse through all the messages on the Hello From Earth website (click on the first link posted at the start of this journal entry), and count to see how many of them actually have proper grammar and spelling. Not much. Granted, folks from all 195 nations (as well as Antarctica and Vatican City) submitted a message...so I really shouldn’t be expecting someone from Brazil, China or Iran to submit something that would imply they would win an English essay contest or something. But still, it’s just mind-boggling to think that extraterrestrials would get their first perception of Earthlings by reading this garbled nonsense. Oh well. Despite all this, I hope that COSMOS Magazine has another opportunity like Hello From Earth next year. After all, there are still more than 350 ‘exoplanets’ out there for us to send badly-worded greetings to. Live long and prosper.
August 17, 2009