Special Blog Post:
The Moment of a Comet
On January 12, Comet McNaught reached perihelion at only 16 million miles from the sun, which slung it around to emerge for people on Earth as an evening flare quietly shining in the low southern skies. It has a round, fuzzy head of volatile gas and dust, and a short, slightly delta-shaped tail of dust particles falling away. In the coming nights, it will be visible later into dusk, but it will be getting fainter as it slips away from the sun and Earth. Soon, it will be too dim to see with the naked eye.
Because it came in on such a tight trajectory, the sun's gravity has probably given the comet so much additional speed that it now has "escape velocity" from the solar system. That means it will never return. It will cruise out into the cold, stark emptiness of interstellar space, where it will forever slip through the bright darkness of faint galactic gravity fields and soft star winds, nothing but a tiny speck of ice and dust never again to be seen by human eyes, almost certainly never again to be sensed by any sentient being like us.
But we saw it; and in that almost meaningless moment when it was warmed by the sun, it was simply beautiful. If that matters when you think about comets, then let it matter when you think about yourself.