If our Sun blew up, we would only learn about it eight minutes after the fact – that’s how long it takes the light to travel here. If you had a friend on Mars and wanted to have some sort of chat with them, it would take between 4 and 24 minutes between each message, assuming they were transmitted via radio signal. The time delay in space reminds us how bloody far everything else is from our own little speck of a planet. Even our closest neighbour planets, not to mention other bodies.
Today all the nerdworld was anticipating the Philae lander’s detachment from the Rosetta spacecraft in order to descend on the comet chased by the European Space Agency for the past decade. The descent is actually still happening as I write this, because the lander did separate successfully; in four hours or so the world will know whether the first landing of human equipment on a comet has been successful as well.
The comet, named 67P/Churyumov-Gerasimenko, is out there beyond the orbit of Mars, and it takes even longer for messages to reach us from there. Even though Philae was scheduled to separate at 8:35 GMT, mission control had to wait with a baited breath for 28 minutes and 20 seconds to receive confirmation of its success. In unmanned space exploration these time windows are akin to a limbo, like when you know for certain that your exam has already been graded, but the results are not in yet.
What I’m really trying to get at here is that if humans ever colonise more than one body in our Solar System, there will never be instantaneous communication between different planets. We can certainly forget about interplanetary real-time video conferences.
Meanwhile, we can wish Philae all the best and hope that it doesn’t shatter on a jagged rock protrusion, or fail to latch onto the comet’s surface with the harpoons it’s equipped with.