Season's greetings

Two timely efforts to send good tidings abroad in the universe have caught my attention this holiday season. Both are addressed to spacecraft already launched on their missions of discovery. As has happened before in mounting efforts of this kind -- the pictogram plaques attached to Pioneers 10 and 11, the golden records aboard Voyagers 1 and 2 --messages from Earth make their greatest impact on Earth. When the Juno spacecraft rounded the home planet on October 9 for a gravity assist along its flight to Jupiter, the global community of ham radio operators united to salute it. As you can see in this video just released by the Jet Propulsion Lab, even the tapping of signal keys can swell with human emotion.

Hearing the Earth's hello, the spacecraft returned a short travelogue of its flyby. This is the only known footage of the Earth and Moon as they might appear to spacefaring visitors arriving from afar.

The New Horizons spacecraft, launched in 2006, has already passed Jupiter and is fast approaching its Pluto destination. After exploring Pluto and the five Plutonian moons in the summer of 2015, it will continue through the outermost regions of the Solar System, into interstellar space. This trajectory suggests that New Horizons might be the ideal medium for a message.

More than 7,000 Earthlings have already signed a petition urging NASA to upload a greeting as soon as New Horizons has completed its primary mission. The message content is currently a blank card, pending NASA approval and input from the widest possible community of well-wishers.

Peace on Earth. Good will to all nations.