Vinka till Saturnus ikväll!

Klockan har precis passerat midnatt när detta skrivs. Idag, fredagen den 19 juli, uppmanas vi alla vinka till Saturnus. NASA:s rymdsond Cassini ska nämligen ta ett historiskt foto av jorden, som bakgrundsbelyses av solen. Det sker som en hyllning till den bild som rymdsonden Voyager 1 tog 1990 av jorden, denna bleka lilla blå prick ("the Pale Blue Dot") i rymden. Robert Cumming ger lite mer information om det hela på Populär Astronomis websida. Läs också om det på NASA:s websida.

Mellan klockan 23.27 och 23.42 är det läge att söka efter Saturnus, lågt i sydväst på stjärnhimlen och lite till höger om månen. Det tycks kunna bli en klar himmel. Planeten syns tyvärr inte för er som är i norra Sverige. Själv är jag i Göteborg och tänker absolut gå ut i sommarnatten och vinka.

Saturnus (Bildkälla: NASA)

När rymdsonden Voyager 1 tog bilden 1990 var det från ett avstånd på ca 6 miljarder kilometer. Dels var det en intressant bild av vår jord, dels ville den legendariske Carl Sagan med bilden ge ett lite djupare perspektiv på vår plats i universum:

"From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity – in all this vastness – there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we've ever known."

—Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space, 1997 reprint, pp. xv–xvi

Det är ack så tänkvärda ord.

Voyagersondens bild av "the pale blue dot" (Bildkälla: NASA)