Today a few news outlets picked up the confirmation of the discovery of an Earth-like planet in the habital zone of a star 600 light years away, but the closest such planet discovered so far. This has created an excited buzz as indeed it should. Life certainly exists elsewhere in the universe, and we know a planet like ours can sustain life quite well, albeit grudgingly at times, so finding a planet like our own “just” 600 light years away is indeed exciting.
Well, is it? Alas I am a bit meh about the whole thing.
Let’s assume that there’s a civilisation as advanced as ours there. The bads news is that we’re never going to visit them, and we’re never going to establish meaningful communications with them. Let’s look at the best possible timeline.
A “Hello Kepler 22-b” signal sent today will reach them no earlier them December 5th 2611 so we’ve got some finger tapping to do between now and then. And we’re assuming they’re looking for a signal, and spot it, and can decode it. If they do all that, and send us back engineering plans for their FTL communications device right away, then we’ll be getting those no sooner than December 3211, twelve centuries from now. And then we merely have to build a device designed by an alien species who almost certainly won’t be using the same engineering principles we are.
Remember what happened to the Mars Climate Orbiter?
Okay, so while we’re waiting, let’s send a ship up there. Twelve centuries is plenty of time to develop space exploration technology. At some point during this maybe we will figure how to build a useful FTL communications device, in which case we can beam the specifications over to Kepler 22-b. It’ll be at least a 600 year wait for them to get back to us, but no harm in trying.
If we’re sending a ship, and we don’t have FTL yet, manning it isn’t really an option. At light speed, it’s a 600 year trip, at half light speed it’s 1200 years, and so on. People just don’t live that long so we’d be looking at building a generation ship, currently way beyond our current technology, and beyond anything we’re likely to achieve in the next century at least.
Unmanned is easier, and we’re good at that. We’ve had probes in space for decades that are still working just fine. None of the complexities of life-support, all that’s needed is a nice big nuclear plant for electricity and a nice big antenna for talking back to Mother Earth. Cunning use of orbital slingshots, especially using the gas giants, means we could get this baby really moving through space. With the nations of the world behind the project, we could launch this inside a couple of years carrying all the knowledge we dare share with the Keplians. And then, again, we sit back and wait, and work on that FTL communications device.
The fastest speed attained by a probe launched from Earth is about 157,000 mph. This was achieved by Helios probes using the Sun’s gravity well. We have a pretty good grasp of orbital mechanics, so I don’t expect it’d be too difficult to design a slingshot approach to the Sun that would take our probe, accelerate it to this sort of speed and then send it in exactly the right direction to meet up with Kepler 22-b in a few years time. That was sarcasm. We have zero experience of sending probes into interstellar space, the existence of a planet tells us nothing about how to navigate a probe through distant gravity fields to get there. Despite the moon’s gravitational interaction with the Earth being quite well understood, Apollo spacecraft on trips to and from the moon routinely had to use course-correction burns to make sure they attained successful moon orbit and earth re-entry.
So we do build our probe, and we do manage to find a course to send it on its way at 260,000 (we got better) km/h. What next? Well what happens is we wait. A long time.
The Solar system is big, much bigger than most people realise. At the center is our Sun and one of the furthest significant objects from it we know about is Pluto. Worst case, Pluto is 48.871AU from the Sun, that’s roughly 7.38 billion kilometers. Time to get there at our probe’s speed is 28,120 hours, or 3 years. Not too shabby. Alas Pluto is not the edge of the solar system.
Voyager 1 will beat our probe to interstellar space. It’s currently about 2.5 times further away fom the sun than Pluto is. Being generous, launched today, our probe will get there around 2020. Voyager 1 was launched in 1977. So off into the inky black and on to Kepler 22-b.
Alas this is still not the edge of the solar system.
It it theorised that there is a sphere of leftover junk from the formation of the solar system called the Oort Cloud. It’s thought to be where some of our long-period comets come from. Recall that Pluto, at worst was about 49AU from the Sun? Well the Oort Cloud is thought to be 50,000AU from the Sun, and marks the edge of the Sun’s gravitational influence. Conveniently, this is quite close to the distance of 1 light year. Less conveniently, this means our probe is going to take the thick end of ten millenia to make it this far at best speed. Keppler 22-b is 600 light years away, so a mere 5 and a bit million years in space for our probe.
I would like to think that mankind will travel between the stars. But it’s not going to happen in my lifetime, nor is it likely to in the next several centuries. Looking out into the universe to see what we can learn is great science but, really, we need to focus on making sure we survive as a species, something we seem determined not to do.
We should have had a permanent manned presence on the moon by now. We have taken all the hard work done to get us to the moon and allowed it to be washed away. With the end of the space shuttle programme, the country that worked hardest to put a man on the moon now has no way of putting a man in orbit. And we watched and allowed that to happen.
I consider myself to be an orphan of the Apollo project.