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A Matter of Scale

Note: this post was first published on Feb. 22, 2011. I’m reposting it again today because 1. the video creator has since updated the soundtrack, and 2. it’s still awesome.


One of the things that fascinates me so much about the Universe is the incredible vastness of scale, distance and size.

On Earth we have virtually nothing to compare to the kinds of sizes seen in space. We look up at the stars and planets in the night sky but they are just bright points of light. Some brighter, some larger, some slightly different colors. But they’re still just points from where we stand. Even from space, seen by telescopes or by astronauts in orbit….still just points.

But they’re so much more than that, obviously.

Read the rest of this entry

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The Colors of Titan and Saturn

Titan seen in front of Saturn’s limb (NASA/JPL/SSI/J. Major)

The pumpkin-orange colors of Titan’s thick clouds appear in stark contrast in front of the limb of Saturn, which appears quite blue along its sunlit limb due to Rayleigh scattering, the same process that makes the sky look blue here on Earth.

The image here is a color composite made from three separate raw images acquired by Cassini on July 1, 2012. Captured in red, green and blue visible light wavelengths, when combined the result is a more-or-less true color image as our eyes might see it. The final image was rotated to make the angle of sunlight come in from the left horizontally, and I teased out some detail in Saturn’s atmosphere.

Cassini was over 1.7 million miles from Titan when the images were captured.

Credit: NASA/JPL/SSI. Edited by J. Major.

On a related note, today another Saturn/Titan color composite I assembled in May was chosen for the popular Astronomy Picture of the Day page, or APOD as it’s known. Check it out here. The image first appeared on Universe Today on May 11, and was thereafter picked up by ESA and from there made its way to APOD. Very cool!

A Matter of Scale


One of the things that fascinates me so much about the Universe is the incredible vastness of scale, distance and size.

On Earth we have virtually nothing to compare to the kinds of sizes seen in space. We look up at the stars and planets in the night sky but they are just bright points of light. Some brighter, some larger, some slightly different colors. But they’re still just points from where we stand. Even from space, seen by telescopes or by astronauts in orbit….still just points.

But they’re so much more than that, obviously.

Our planet Earth is big. (To us.) Most of the other planets are bigger. (To us.) Our star, the Sun, is much bigger still.

(Again, to us.)

Other stars, other suns, are even bigger than that. And this video gives a wonderful illustration of just what sort of scale is involved.

Featured on the Astronomy Picture of the Day this video by YouTube user morn1415 shows the comparative sizes of most of the planets in our solar system with our Sun, and then with other stars in our galaxy. It’s a great perspective on the actual scale of those little points of light in the night sky, and therefore the distances that must be involved as well. (And why it’s not so easy to find other Earth-sized planets!)

After all, in the grand scheme of things, we’re not very big at all. (Except to us.)

Enjoy!

Video by morn1415

*yes, there’s no Uranus and the planets (except Venus) are rotating the opposite directions. Don’t get too caught up in the example. 🙂

Haunting Beauty

Can’t see the video below? Click here.

Vodpod videos no longer available.

Congrats to Tor Even Mathisen for making the Astronomy Picture of the Day today with his beautiful time-lapse video of the aurora borealis illuminating the night sky over Tromsø, Norway! I first came across this video last week on Bad Astronomy, it’s a hauntingly beautiful presentation of the northern lights in action. Really stunning. I have never seen them in person…I would love to someday, either from the ground or from above! (Hey, it could happen….) Anyway, you just gotta watch this!

Credit: © Tor Even Mathisen. Music: Per Wollen; Vocals: Silje Beate Nilssen

Fo Sizzle

A prominence rises and twists above the Sun's limb. © Alan Friedman.

A beautiful photo by Alan Friedman showing a solar prominence twisting high – as in, tens of thousands of miles high – above the surface of the Sun. This image was taken on June 2, 2010 through Friedman’s hydrogen alpha telescope. This allows us to see the complex texture of the Sun’s surface, called the photosphere, as well as the relatively thinner – and much hotter – glowing layer just above called the chromosphere. Flame-like structures called spicules form a constantly moving and jagged boundary to the chromosphere when seen along the Sun’s limb, as in the photo above.

Here’s another fantastic image of the entire Sun posted by Alan a few days earlier. Very cool!

UPDATE: The image in the above link ^ is the Astronomy Picture of the Day for today, June 9! Congrats to Alan on that!

Image ©Alan Friedman. All rights reserved.

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