YEP, another post today. But this one happened yesterday. And sort of the day before. So I am writing this from the past. Which is actually relevant, for once.
SO, does this ever happen to you??
Okay, so not really that. I mean you think of something and decide you want to know more about it. So you look it up. And while reading that you come across something else you find interesting and look that up. This leads you to something else and before you know it you’re lost in a sea of knowledge drifting ever further from where you began until you don’t even know how you got there.
Yeah. That happens to me a lot.
So this time, I started by looking up something and an hour later found myself looking at this:
Why yes, I do want the color exaggerated version, NASA. You know me so well.
Pretty nice work-up, though obviously fake.
No. Courtesy of the Cassini Solstice Mission. And the best part is we’re in it.
Fun fact: That little blurry bit at about the 10 o’clock position on the other little blurry Earth bit, is the moon.
So now I am going down the rabbit hole and I must know why NASA has this picture of me. Should I be worried? Am I being stalked by Cassini from space? Do I need a restraining order or is there a moon-made ring in my future?
It’s time to roll up those sleeves, because we’re diving in.
So according to the official data, this is a compilation of 165 images taken by Cassini’s multiple instruments over a period of 3 hours on September 15, 2006. One of these instruments can image a 2.4cm area from a distance of 4km. This particular series covers 260km (or 162miles) per pixel. I’ll give you a minute to let that sink in….
Also, this is a picture of Earth from the past.
Okay, yes. I know, all pictures are from the past. And I did just say this was taken in 2006. I got it. But stay with me here.
As I looked at this, I began wondering how far in the past the Earth was from the point of view of Cassini. Not how old, how far in the past. For example, the Earth is roughly 8.33 light minutes from the sun. So technically if you notice the sun is glaring off your computer screen like it does, it was actually in the position to do so 8.33 minutes ago and has since moved on. You’re seeing the sun on an 8 minute delay. Still with me? Good.
Now, Saturn is roughly ten times as far from the sun as the Earth and, as you can see, Cassini took this photo from beyond Saturn while facing the sun. So I looked into the statistics and found that Cassini was 2.2 million km from Saturn when it took this:
1 light minute = 17,987,547.5km
2,200,000km / 17,987,547.5km = 0.1223 light minutes OR roughly 7.3 light seconds
This means Saturn was roughly 7.3 seconds in the past to Cassini at the time the images were captured.
Also, Cassini was 1.5 billion km from Earth:
1,500,000,000km / 17,987,547.5km = 83.391 light minutes
Which means Earth was roughly 83.4 minutes in the past to Cassini at the time the images were taken.
So really what we’re looking at is:
These images were then sent to Earth via one way radio transmission at the speed of light taking roughly 1hr 24min to get here.
Now who says science isn’t fun??