While I'm sure this is how at several alien invasion movies started, I kind of like the idea of beaming signals into space to see if they get picked up by aliens. Just so we can hopefully figure out whether they're actually willing to talk back. Humans have been beaming signals into space for decades, but now METI has announced it's sent out one deliberately designed to attract the attention of alien life.
This transmission project is called Sónar Calling GJ273b, and is a collaboration between METI, the Institute of Space Studies of Catalonia (IEEC), and Spanish music festival Sónar. They sent the signals to Luyten's Star, a Red Dwarf located 12.4 light years from Earth that was chosen due to the presence of a potentially habitable exoplanet dubbed GJ273b.
The transmission was beamed out over three successive days (16th-18th October) using the EISCAT 930 MHz transmitter in Tromsø, Norway. Included in the message were 33 10 second music clips, commissioned from a diverse group of musicians designed to represent Sónar's 'exploratory approach' to music over the past 25 years.
The first message also included a scientific and mathematic tutorial that describes the concept of electromagnetic waves and radio signals as a communications tool, starting off with the basics and gradually getting more complex. The idea is that if aliens don't know what radio is they'll be able to work out how to respond. Plus, unlike past attempts which relied on imagery, these tutorials should be able to be interpreted by alien species if they don't have vision as we know it.
It also included a 'cosmic clock' which details how we earthlings perceive time. Each message beamed out was exactly the same, except for the clock element, which changed with each successive transmission.
This first message only sent out signals using two different frequencies, but a second message (due to be beamed out next April) will use a multitude of frequencies to mimic the musical scale and effectively turn the transmitter into a musical instrument. This message is designed to describe the physics and psychology of music perception, and will end with a countdown to the time when we will start listening out for a reply - 25 years from now.
God speed signals, just don't bring back an invading force, mmkay?