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Hubble Reveals Latest Portrait of Saturn (spacetelescope.org)
184 points by cow9 32 days ago | hide | past | web | favorite | 49 comments

This summer I gazed at Saturn through an inexpensive telescope my dad found at an antique store. The image was tiny, and rather black-and-white, but the rings were sharp and unmistakable. Despite the lack of resolution, it was one of the most magical things I’ve seen. Seeing Jupiter and its moons was pretty great too.

Such a cool feeling isn't it? Never forget the first time I saw those rings in person through a cheap telescope. It somehow places you in the same universe you've only read about till then.

Some three years ago, I had the exact same experience—except that it was a high-end telescope at the observatory, with an equatorial mount and all other gear. I was mesmerized enough that I did a silly thing: pointed my Nexus 5's camera towards the telescope's eye piece to capture a hint of the Saturn. And ever since it's been my phone's wallpaper.

That's[1] the result. It's an understatement to say "it's nowhere near as sharp", but you can clearly see the shape of the rings there.

Another favourite of mine is the stunning blue-gold double star, Albireo[2]. Both the smaller blue star and the larger gold star are very distinct. Absolutely recommend it.

[1] http://kashyapc.fedorapeople.org/Saturn_through_Nexus_5.jpg

[2] https://earthsky.org/brightest-stars/albireo-finest-double-s...

I was reminded of the same thing this summer, dragging an old telescope out to show Saturn to my son (for the first time). He was so excited to see a 'cartoon planet' for real, it gave my indifference to what you can see in a small telescope a sharp readjustment.

My grandmother bought me a 60mm (main lens) telescope as a young teen. After a few nights of gazing, I learned how to spot things I hadn't seen at first, like the belts of Jupiter, and parts of the Orion nebula I hadn't before. The more practice the more you can see. I found it odd one had to "learn to see", but it's usually the case.

In case it whet your appetite for more tastefully shot imagery of heavenly bodies:


This backlit view from Cassini is one of the most amazing. It's not a view one can see from Earth. https://solarsystem.nasa.gov/resources/13315/in-saturns-shad... (Note: colors are enhanced a bit)

Took me a minute to figure out the shadow at Saturn's equator, but it looks like the rings basically illuminate the entire planet and the shadow is just where the dust from the ring blocks the reflected light from the sun.

Read an article about how Titan would possibly be a better location for humans to land first, and one of the benefits listed was that you could see Saturn's rings up close. Amen. :)

The back rings are also in sharp shadow that happens to mostly match the shape of the planet from that angle.

Re: Titan would possibly be a better location for humans to land first, and one of the benefits listed was that you could see Saturn's rings up close

Titan's hazy atmosphere may make viewing Saturn itself tricky. It's debated how much it's "fogged out" and how often there are partial clearings in the haze. But at least the atmosphere can protect one from Saturn's radiation.

I can’t get over how much the Mimas shots at that link remind me of the Death Star, but not surprisingly, I’m not the first to think that it seems.

The number of years of service and usefulness of Hubble is truly astonishing. I even remember news, almost joking about its initial mirror flaw which inflicted ironically an almost blindness, so much so people thought it would be fatal. NASA & Hubble seem to have had the last laugh on this one. Long live Hubble!

But the repair costs were astronomical (pun semi-intended). However, the experience helped with future maintenance missions. Part of the reason for the flaw was paranoia about leaking tech to other countries that could result in spy scopes, which made testing tricky.

Original image: https://hubblesite.org/image/4565/gallery

It has smaller resolution compared to older Saturn images.

I like your link better, it doesn't fail my filter of sensationalised title and provides interesting information in the description. Thankyou!

Thanks, much better. The posted article is insanely slow and clogged by ads (over 600 http requests)

Additionally, the posted article is a watered down version of this one; the journalist just rewrote paragraph by paragraph but in less detail.

Praised be the adblocker.

Mike Massimino's book, Spaceman, includes a captivating account of what it was like to spacewalk on Hubble. He went on two Hubble servicing missions, including the final one when the WFC3 was installed—the camera that captured this new Saturn image.

Why can't you see any stars in these pictures or the video they posted? I'd expect to see thousands of stars.

Because they choose not to take photos of the surrounding stars, and those that are visible they either photoshop out or process the images in such a way that they're not visible.

There's a sibling comment saying it's due to the exposure, that's wrong. That's not how Hubble works, it's not just a giant digital camera in orbit. The "photo" you're looking at is a composite from tens or hundreds of other images, so to start with most of the pixels you're looking at are just black filler.

You can see the black and white raw images at http://hst.esac.esa.int/ehst/#home search for "SATURN" under "Solar System Objects" and sort by date. A lot of the Hubble images from June 20th, 2019 have stars, including some visible between the rings and Saturn. They were just edited out because showing them wasn't the point.

Are those stars? The “iduy37thq” image [0], for example, has various star-like points of light on top of the planet itself in addition to appearing in the background.

[0] http://hst.esac.esa.int/ehst-sl-server/servlet/data-action?R...

No they're probably not (I'm an astronomer). They're likely cosmic rays. When I've used Hubble data, then the processing uses multiple images to remove the cosmic rays (which aren't in common between images).

I'd love to understand how those bright dots and lines (so, cosmic rays?) appear on these images.

They're just high energy particles that interact with the CCD cameras typically used for astronomy. You get a bright point or particle track, as the particle interacts with the CCD producing electrons. This is worse for space telescopes, as there are more cosmic rays in space. For some simple information see: http://spiff.rit.edu/classes/phys373/lectures/cosmic_rays/co...

This look like the noise I get from my camera when I take very long exposures (> 10 minutes). The sensor starts heating up and producing these dots.

I'm an astronomer, and I think you're probably wrong. It's mostly down to exposure. Those little dots you're seeing in the images are likely cosmic rays. Those are removed by combining multiple images, as cosmic rays don't appear in the same places.

The pixel-sized dots are cosmic rays, those are obviously artifacts as some of them can be seen in front of Saturn.

I'm referring to objects you can consistently see between different observations. E.g. this one around 1/2 a planet width from the pole you can't see observed from 2018-06-06 14:35:05 until 2018-06-06 14:46:35:





Although looking again perhaps that's a moon of Saturn's rather than a particularly bright star.

Not an astronomer, just an interested amateur. The few times I've been curious enough to look at the raw data behind these images I've found background celestial objects that are definitely edited out. That's understandable, the point is to show e.g. Saturn and not whatever background objects happened to be there at the time Hubble took the photo.

I'm just pointing out it's not all due to the light exposure.

Is there a good explanation/article about how they take/process these images? I would have liked it if they could have included a bit of text about why certain items were not in the picture/removed.

The exposure is adjusted for Saturn which is much brighter than the stars.

Similarly, fake-moon-landing conspiracists don't seem to understand the large magnitude of differences between heavily objects. Sunlight is typically so much brighter than stars such that the exposures best used in sunlight will wash out stars (make their images be swamped by sensor noise). This happens even as far out as Saturn, which gets much less sun than our moon. Thus the "no stars in photos" argument about Apollo holds no water.

Even in a backyard telescope, if you look at Saturn, its brightness will wash out all but the very brightest of nearby stars because your eye adjusts for Saturn's brightness, not star brightness. (One nearby "star" you may see is actually the moon Titan.)

The New Horizons probe did pick up star images in Ultima-Thule images, if you look at the raw exposures, but Ultima-Thule is really far away from the sun, beyond Pluto. And it's a dark body, requiring sensitive camera settings. Note that some raw exposures from some probes will show streaks that may be mistaken for stars, but are actually cosmic rays. They are usually digitally removed from final versions.

The boundary where planetary exposures will start to clearly show stars is roughly around Neptune's or Pluto's orbit. But processing may have to remove them because time-lapse and/or multiple exposures may be needed to properly capture dim planets and rocky bodies that far out. Any stars caught would otherwise look smeared or smugdy.

Thank you, that makes perfect sense. I would still love to see what it looks like with the naked eye.

Same thing that people ask about the Moon landing photos. Where are the stars?

That said, it would be amazing to see HDR images of these stellar bodies.

Here's a picture of some of the light even HDR wouldn't likely uncover:


EDIT: A larger version of the image, with an equally huge url: https://m.esa.int/var/esa/storage/images/esa_multimedia/imag...

HDR and wide-spectrum are extensions along different measurement axes.

You can even see the hexagonal pole from Hubble! Amazing!

Full size image: https://www.spacetelescope.org/static/archives/images/origin...

Link to the original video:


It might save you some time

From the image titled The Moons of Saturn (annotated)[1], what relevance do the arrows denoting "North" and "East" have?

I'm genuinely dumbfounded by the concept of cardinal directions in space.

[1] https://www.spacetelescope.org/images/heic1917b/

This is from memory, so apologies if vastly wrong.

North is the direction out of the solar system plane in the same direction as Earth's North. East is prograde; tangent to the radial line from the sun, and in the direction of travel about the sun.

Quickly googling I discovered that Saturn is considered to 'Rule the West' in some astrology circles, but alas I think that may not help this discussion.

Was trying to figure out why it looked photo-shopped to me. Realized the planet looks cut and pasted on to the rings due to the planets shadow on the rings being just barely visible behind giving it a black outline look. Well I'm assuming its the shadow...

Also the nearly precisely head on lighting, that comes from exactly 1 point. The lack of any atmospheric distortion. The perfectly clean background.

Hubble is a fantastic program that gets far too little credit IMO.

I'm not sure how much more credit it could get. It is extremely well known inside and outside of technical circles. Its images are often the face of astronomy as a whole - and credited as such.

There was a lot of criticism of the cost of the Hubble program in the beginning and then then mirrors failed after it was initally placed in orbit, turning Hubble into a national joke. NASA and Congress seriously considered abandoning Hubble then and a couple more times in the last two decades.


Wow. It really looks like created in Blender or similar program!

I read a journal claiming saturn would lose its rings over a period of time. Wonder how the solar system would look a few hundred thousand years later..

Nice image, but the article is Buzzfeed-tier garbage.

The official URL from the ESA (European Space Agency) / Hubble Information Centre newsletter was:


Exposure is too long, all details lost.

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