One way to obtain a sense of scale for something like comet 67P is to contrast it with something else, such as Manhattan Island in New York.
As I mentioned in a column I posted yesterday about the MRAM company Spin Memory (see Spacing out with Spin Memory), it’s now six years since the Philae lander from the European Rosetta space probe performed the first successful landing on a comet, where comets are essentially cosmic snowballs of frozen gases, rock, and dust that orbit the Sun.
The comet in question was 67P/Churyumov–Gerasimenko (abbreviated as 67P or 67P/C-G), which is a Jupiter-family comet that originated in the Kuiper belt way back in the mists of time.
I must admit that I’m enthralled when I see photographs of asteroids and comets. When I was a kid, I read way too much science fiction — I still do so to this day — and I can easily imagine being in a space suit standing on one of these awesome objects.
Having said that, when you see an image of something like comet 67P in isolation, it’s hard to get a sense of scale. So, I had a quick Google (no one could see because the door to my office was closed) to discover that 67P is 4,350 meters (2.7 miles) long. As interesting as that is, I still wanted to put this into context.
A couple of years ago, I visited New Jersey with my wife (Gina the Gorgeous). At that time, we both used to enjoy watching the American docusoap television series Jerseylicious, which chronicled the lives of six hair stylists who worked at salons located in Green Brook Township, New Jersey. The main salon was called the Gatsby, so I’d booked Gina an appointment there as a surprise for her birthday (I’d also ordered a birthday cake from Carlo’s Bakery, as seen on the Cake Boss, which is also based in New Jersey).
The reason I mention this here is that, from our hotel room in New Jersey, we had an awesome view of Manhattan Island in New York, and we managed to spend a day there wandering around. My Googlicious friend informed me that Manhattan is 13 miles (20,900 meters) long and 2.3 miles (3,701 meters) across at its widest point. Armed with these facts, I asked my graphics artist chum, Bruce Till, if he could create a montage contrasting Manhattan and comet 67P, which he did as shown below.
Now I have the sense of scale I was looking for. I know how long it takes to walk across Manhattan because I have done so. Of course, it would take much longer to walk around 67P because trying to travel any faster than a geriatric snail would cause you to overcome its escape velocity, which is only around 1 m/s. By comparison, the escape velocity from Earth’s surface is about 11,186 m/s (which is 40,270 km/h or 36,700 ft/s or 25,020 mph).
To put this another way, as I just read in this article on Slate, “If you were standing on the surface, you’d feel gravity something around 0.0001 times that of Earth. I’d weigh about a quarter ounce, as much a sip of water.”
Now my poor old noggin is abuzz with thoughts of exploring 67P. On the other hand, I’m also reminded of the book Heart of the Comet by David Brin and Gregory Benford. As it says on Amazon, “This tells the story of an ambitious manned mission to visit Halley’s Comet and alter its orbit, to mine it for resources. But all too soon, native cells — that might once have brought life to Earth — begin colonizing the colonists.” That’s another book I need to read again in the not-so-distant future. In the meantime, do you have any thoughts you’d care to share?