Richard Zurawski

I don’t know if you have been following the space satellite named Messenger, but this robotic space voyageur has been doing some pretty spectacular stuff. For starters, where most other space ships head off for the deepest, darkest, nether regions of outer space, this probe is headed in the opposite direction, towards the one of the hottest planets in the solar system, Mercury. Mercury is the planet closest to the sun and because it is so close to the sun, not many people have actually ever seen it, because it gets lost in the overwhelming glare of the sun.

Unlike Venus, the only other planet in the solar system closer to the sun and the Earth and whose surface is actually hotter by virtue of the fact it is shrouded by a brilliant white clouds which make it the brightest celestial object in the sky other than the sun or the moon, Mercury has no atmosphere and is barely more than a rock.

And why are we interested in a chunk of rock circling the sun at a distance only 40 times   the sun’s diameter in the first place? Basically, it is because we don’t know much about Mercury because we don’t see it much. Mercury is so close to the sun that it can be seen only just before sunrise or after sunset, and then it is a only faint point of light.

For the longest time we thought that Mercury was locked in a synchronous orbit around the sun, always having one face permanently facing the sun. We learned otherwise from the last time we sent a probe to Mercury 30 years ago. What we learned was that while Mercury orbits the sun every 88 days, it’s day is 58 days, locked in a resonance giving three days for every two years.

It is the surface of the planet that is of so much interest. It appears that Mercury has giant ridges on its surface which seem to indicate that the planet is shrinking because its interior is cooling and becoming smaller while the outer layers remain the same size. The outer layers are like having too much skin. This outer layer or skin then sags, as the inside shrink, creating craggy ridges as gravity pulls the loose folds inwards.

What other mysteries will be solved and what new questions and conundrums come to being remain to be seen. Did Mercury ever have an atmosphere, perhaps when the solar system was just being born, when the sun was much dimmer? What about plate tectonics? Was its interior ever molten enough to cause the drifting, pushing and pulling on its crust that has made the Earth so dynamic?

This amazing Robotic spacecraft is the wave of the future. Smarter and smarter spaceships are being created and launched at a fraction of the cost of people carrying ships. In a couple of decades spaceships with near human capacity will allow us to be Earth bound voyeurs and maybe even cyber voyageurs if we can get establish the links.