APOD: Ancients of Sea and Sky (2018 Jun 19)

[APOD Robot]

Ancients of Sea and Sky

Explanation: They may look like round rocks, but they're alive. Moreover, they are modern versions of one of the oldest known forms of life: stromatolites. Fossils indicate that stromatolites appeared on Earth about 3.7 billion years ago -- even before many of the familiar stars in the modern night sky were formed. In the featured image taken in Western Australia, only the ancient central arch of our Milky Way Galaxy formed earlier. Even the Magellanic Clouds, satellite galaxies of our Milky Way and visible in the featured image below the Milky Way's arch, didn't exist in their current form when stromatolites first grew on Earth. Stromatolites are accreting biofilms of billions of microorganisms that can slowly move toward light. Using this light to liberate oxygen into the air, ancient stromatolites helped make Earth hospitable to other life forms including, eventually, humans.

<< Previous APOD

This Day in APOD

Next APOD >>

[Ann]

Nice picture. Stromatolites are fascinating.

What is the brightest light on the left side below the Milky Way? Is it a planet? If so, which one?

What is the brightest light on the right side above the Milky Way? Is it by any chance Omega Centauri?

Ann

[heehaw]

Thank you, stromatolites! And we will repay you by ....

[Chris Peterson]

Thank you, stromatolites! And we will repay you by ....

Recreating a world where you will once again be the dominant life form.

[SeedsofEarth]

Shouldn't these guys have evolved by now? (only kidding?)

[ta152h0]

Human discoveries artistry and science

[khh]

Now that's staying power.

[felstedian]

Could I put my hand up and ask if APOD could please refrain from describing and showing the Milky Way as an 'arch'. It isn't.
It is (from our point of view) an elliptical area of denser stars, and the major axis of the ellipse is a straight line, not a curve.
To show it as an arch, as APOD likes to do, means someone has transformed and stitched together a bunch of photos. Do they do this because they think it looks more appealing? Or are they trying to impress us with their desktop publishing skills?
However, the stitching and transformations distort the image. I think that is unscientific at the very least.
Isn't the MW just as beautiful in its original straight form?

[Chris Peterson]

Could I put my hand up and ask if APOD could please refrain from describing and showing the Milky Way as an 'arch'. It isn't.
It is (from our point of view) an elliptical area of denser stars, and the major axis of the ellipse is a straight line, not a curve.
To show it as an arch, as APOD likes to do, means someone has transformed and stitched together a bunch of photos. Do they do this because they think it looks more appealing? Or are they trying to impress us with their desktop publishing skills?
However, the stitching and transformations distort the image. I think that is unscientific at the very least.
Isn't the MW just as beautiful in its original straight form?

How would you portray it? The Milky Way is a ring, not a line, and when you're standing in the middle of a ring with half of it blocked from your view, it becomes an arch. The sky is a curved surface, your monitor is not. In order to map the sky onto a flat image, some kind of projection distortion must exist. Would you prefer that a wide angle image present the Milky Way as a line and the horizon as a great smile? Is that more realistic?

There is nothing unrealistic nor unscientific about images like this. Would you prefer it presented this way?
-

MilkyWayStromatolites_Zhang_lin.jpg (25.62 KiB) Viewed 8363 times

[SeedsofEarth]

I have seen several very impressive stitched images of the Milky Way that presented the galaxy as it would appear to someone outside the disc of stars and dust we call home. Actually, the Milky Way is made up of several arms, and if one is in the right position between two of those arms, one would actually see both arms, one in front and one in back. Our sun is in the Orion spur between the Scuttum-Centaurus arm and the Perseus arm, with the thinner Sagittarius arm passing across the view of the Scutum-Centaurus arm. Therefore, if we were out in space without the earth to block our view, shouldn't we be able to see the Perseus arm behind us if we do a 180 away from our view of the galactic core? Can the astronauts in the ISS see these arms?