Maybe we’re on Mars because of the magnificent science that can be done there — the gates of the wonder world are opening in our time. Maybe we’re on Mars because we have to be, because there’s a deep nomadic impulse built into us by the evolutionary process — we come, after all, from hunter-gatherers, and for 99.9% of our tenure on Earth we’ve been wanderers. And the next place to wander to is Mars. But whatever the reason you’re on Mars is, I’m glad you’re there. And I wish I was with you.
The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends on how well we know this Cosmos in which we float like a mote of dust in the morning sky.
Prior to his untimely 1996 passing, Carl Sagan recorded a message for the brave men and women embarking on the first non-robotic mission to Mars. Here is an excerpt from that message (image source is unknown).
If you live in the Northern Hemisphere, the North Star, or Polaris, guides you true north. You can find Polaris by first locating the Big Dipper and Little Dipper constellations. Polaris is also the middle star in the ‘M’-shaped neighboring constellation, Cassiopeia.
(Movies of jets from young stars at HubbleSite: here)
If you’re like me and maybe a little confused as to what you’re looking at, here’s some more detail (Yes, even Joe has to look stuff up sometimes):
As a star is formed from collapsing dust, ever increasing its density and energy, it begins to form a disk of dust and gas pulled in and rotated by its growing gravity. Perpendicular to this disk, like the tip of a spinning top, some gas is ejected away from the growing star in a high-energy jet. As this collides with interstellar gas, it gives off radiation, which we can observe with telescopes like Hubble.
To see the jets, we have to shift into the infrared and other spectra, as the radiation is outside normal human vision. These movies represent the first time we’ve seen the dynamics of the jets as opposed to still images. More info on protostellar jets here, you star-freaks.
