Christopher McKitterick

NASA’s Cassini spacecraft scientists announce that a form of chemical energy that can feed life appears to exist on Saturn’s moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter’s moon Europa.



“This is the closest we’ve come, so far, to identifying a place with some of the ingredients needed for a habitable environment,” said Thomas Zurbuchen of NASA’s Science Mission Directorate.

“These results demonstrate the interconnected nature of NASA’s science missions that are getting us closer to answering whether we are alone or not.”

Hydrogen gas could potentially provide a chemical energy source for life, and it’s pouring into the subsurface ocean of Enceladus from hydrothermal activity on the seafloor. Ample hydrogen means that microbes – if any exist there – could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water.

This chemical reaction, known as “methanogenesis” because it produces methane as a byproduct, is at the root of the tree of life on Earth, and could even have been critical to the origin of life on our planet (see deep-ocean life that’s billions of years old).

Life as we know it requires three primary ingredients: liquid water, a source of energy for metabolism, and the right chemical ingredients - primarily carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

With this finding, Cassini shows that Enceladus – a small, icy moon a billion miles farther from the Sun than Earth – has nearly all of these ingredients for habitability. Cassini has not yet proven that phosphorus and sulfur are present in the ocean, but scientists suspect them to be, because the rocky core of Enceladus is thought to be chemically similar to other bodies that contain these elements.

“Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth,” said Linda Spilker, Cassini project scientist at JPL).

ALIENS.

Full story: X

Lots more Cassini photos of Enceladus: X

I would never have imagined that a 100mm refractor would be such great deep-sky telescope. I've always been a fan of reflectors, because they offer so much more light for the money than refractors do. This is my first refractor! In the past 30+ years, I've owned at least eight reflectors (including a few I made myself), and still own two big ones: a 12" Schmidt-Cassegrain design that uses a corrector plate across the front opening of the tube to correct the imperfect mirror, and a 17" Newtonian reflector on a simple Dobsonian mount (the cheapest way to get the most light - the 'scope in my userpic). For the price of that 100mm (about 4" diameter lens) - if I had bought it new (I got it nearly new from eBay for a steal) - I could have bought a reflector with many times the light-gathering power. Here's what it looks like:

So why buy such a thing? For one, I already have two wonderful reflectors. But they're both pretty large to lug around (70 and 90+ pounds). I also knew (academically) that, compared to a good refractor, the quality of the image in a reflector suffers because the secondary mirror (and holder) get in the way of the incoming light, and at high powers produce issues at the edge of the field (except in very expensive, multi-optic hybrid designs). On the other hand, a cheap refractor's image only suffers when it disperses the light passing through its lens into various color components, because those different wavelengths of light usually separate, like this:

It turns out that the refractor I bought is pretty kick-ass. The optical design of my 'scope is an "apochromatic ED." Unlike an low-cost but decent "achromatic" refractor, an apo converges all the frequencies of light at the same focal point (or close enough for the human eye). Less expensive "achromatic" telescopes do not use the best glass, failing to converge blue-through-violet light very well, so that range of light appears as a fuzzy halo around the object you are viewing (and usually suffering in sharpness, as well). This is less of an issue with dim objects like globular clusters, nebulae, or galaxies, but it becomes a nuisance with brighter objects like the Moon, stars, and planets. Also, the colors dispersed are lost information, subtracted from the resolution of the object, thus reducing the image quality, thus defeating the entire point of a refractor over a reflector.

To combat these issues, an apochromatic objective uses multiple glass lenses mated together to converge the various frequencies of light, thus managing the refractive dispersion through the elements. Sometimes apos use rare materials (like fluorite or other low-dispersion glass) in the lens composition. As you might imagine, these are expensive propositions - simply adding a second or third lens doubles or triples the cost, and if the glass used costs, say, 10x as much... well, you get the idea. The very best, observatory-quality refractors use a combination of both strategies, and the price for such an instrument is astronomical (ba-da-boom, tsch!).

Mine achieves apochromatic quality by using two lenses, one of which is made of extra-low dispersion (hence the "ED") FPL-53 glass (made only in Japan) to provide super-sharp images with no false color. Mine isn't the top of the line, but it's pretty close. Sure, if it used fluorite instead of FPL-53, it might be slightly better. Or if both lenses were that kind of glass, or if it were a triplet (three lenses). But telescopes like that are MUCH more expensive, costing around $3000 - I got mine, complete with a dual-drive equatorial mount, for about $600. But why? Objects in my 'scope are free of false color (chromatic aberration), sharp, and don't lose any light to dispersion, either.

I've used this 'scope for a couple of years now, mostly because it's so convenient to drag in and out of the house, but never knew all it was capable of. It required a team effort. The real eye-opener for me was how much difference a great eyepiece makes. I've always used decent eyepieces, but these new Explore Scientific eyepieces are frakking amazing! Here's my new case for my 2" eyepieces (the new ones are those with yellow-green spots on the side):

HOLY WOW! The widest field-of-view eyepiece I've ever owned is my William Optics Swan 33mm (it's the one in the photo with the orange bottom cap). It offers 72° apparent field of view (how wide an angle the view in the eyepiece looks to you, the observer), which I thought was pretty amazing. It's still my lowest-power eyepiece (magnification comes from dividing telescope focal length by eyepiece focal length - my 100mm has a focal ratio of f/9, meaning 900mm focal length), offering up a magnification of 27x in this 'scope, with a true field of 2.7° of the sky (about 5 times as wide as the full Moon). Pretty nice, I thought! Sure, the quality of the image at the edge is imperfect, and the sharpness could be better, but it was as nice as I ever used.

Enter the 30mm Explore Scientific 82° wide-field eyepiece of joy.

I started last night's observing session with the Great Orion Nebula, directly overhead in Kansas at around 11pm. The first eyepiece I dropped into the focuser was the most massive once I've ever used, a 30mm with 82° (apparent) field of view. The huge swath of sky it provided was simply astounding - especially when it caught a meteor streaking across the belt of Orion! I didn't bring any astrophotography gear (I was just in my front yard, after all), but here's a nice drawing of about how it looks to the naked eye in a telescope of about this light-gathering power:

This puppy is about the size of my fist and weighs 2.2 pounds (!). Its field of view is so ultra-wide that I had to move my head around to get the full view, making the experience feel like I was looking out through a spaceship's porthole rather than through a telescope eyepiece. Even though the magnification is greater (30x), its true field was wider than with the 33mm! It also has a very large 6.7mm exit-pupil(how wide the cone of light coming through is), which is even larger than some eyes can dilate. It's difficult to explain just how amazingly immersive such a view is until you try it.

Other cool features of this eyepiece: It's O-ring sealing and argon-purged. This makes it completely waterproof, prevents internal fogging, keeps the interior dust- and fungus-free, and makes it easier to clean (no risk of cleaning solution getting trapped inside). It'll stay clear for a lifetime - guaranteed. Its 21mm of eye relief provides unvignetted (no darkening around the edge) views a full inch beyond the lens closest to your eye - this is not only great in general, but makes it easier for eyeglass wearers to observe without removing their glasses. Of course, doing so would mean missing out on a lot of the potential field of view. Its six-element optical design uses low dispersion and high-refractive-index lenses (same benefits as in a telescope's objective) in four groups. All the lens surfaces are fully multi-coated as well, and the lens edges are blackened to improve contrast. All of this adds up to the highest contrast, highest resolution, sharpest resolution, and flattest ultra-wide field of view I've ever seen.

LOVE

Then I moved to the next-smaller Explore Scientific eyepiece, a 24mm (also 82° FOV), which provided 38x and a true field of view of 2.2°, so wide that even the hugely wide Orion Nebula only took up the center of the image. AMAZING! I spent some time with this eyepiece before moving to the next-higher-magnification unit....

Enter the Explore Scientific 14mm 100° apparent-FOV eyepiece. This puppy is just about as large as the longer-focal-length unit (almost 2 pounds), though with a narrower and longer barrel to accommodate nine optical elements of rare-earth glass. Though 100 doesn't seem that much larger than 82, those extra 18° provide nearly 50&percent; wider FOV. So the 64x magnification this one provides still offered up nearly 1.6° of true field - that's three times as wide as the full Moon! This is truly astounding to someone whose prior experience is mostly having used what I thought was a nice Plossl 24mm with 52° FOV - that's less true FOV at much lower power.

So, I asked myself, what will the highest-magnification Explore Scientific unit offer? It has 9mm of focal length, providing 100x... but because of the huge field of view, this high power was still a full degree - twice as wide as the full Moon! I had no idea that a high-power eyepiece could be so comfortable to use, or provide such a "spacewalk" sensation, or offer up such crisp, high-resolution to-the-edge views. Man, now I wish I'd ordered the mega-power 5.5mm that was also on mega-sale! It would have provided 164x while still offering a FOV slightly wider than the full Moon! *boggles mind*

At the end of the night (pretty late by now - after 1am, I'm afraid), I noticed that Jupiter was just starting to peek out from the trees, so I thought why not? Sure, I would be looking a lot of humid atmosphere, over the neighbor's house, and through branches, but it's my fave planet. My apo plus 9mm SOOPER EYEPIECE did not let me down. Four Galilean moons and stormy Jupiter all served up as nice as through a cheap eyepiece looking directly overhead. Just wow.

Oh, and surprise! All these eyepieces turn out to be parfocal, meaning you don't need to do significant re-focusing when shifting from one to the next. That's a major bonus when swapping eyepieces, especially when moving to high magnifications (which also magnify your bumping the 'scope whenever you touch it), where you can lose an object and have to start over finding it at a lower power.

And the best part? We live in an age when you can get incredible eyepieces like this during online, pre-xmas sales for just a little more than the price of a so-so eyepiece (I bought all four for about the retail price of just the 14mm.

HOORAY SCIENCE

Chris

Today is the 25th anniversary of Hubble Space Telescope’s launch! NASA is celebrating with a special Hubble 25th website: x. Hover over the photos below for info.

This one's the hero of our story:




Want to see all the best photos? Check out the Hubble Heritage Site for billions more: x

Have you ever seen anything more astounding or beautiful than Saturn's hexagonal storm system in its north pole?

The eye of this storm is about 50 times larger than the average hurricane eye on Earth. Winds are measured by following small clouds over a five-hour period. The winds at the inner ring are moving the fastest, at speeds of about 340 mph (550 kph) relative to the nominal rate for the planet established by NASA's Voyager spacecraft in 1980. These winds are four times the speed of the Earth's jet streams and more than four times the definition of a hurricane force wind on Earth. (Hurricane force winds blow at 74 mph, or 119 kph.)

The clouds at the very center are spinning rapidly - almost twice as fast as the planet itself, with a period just over six hours. The direction of rotation is counterclockwise, like a northern hemisphere hurricane on Earth, except there is no ocean underneath. A similar feature exists at Saturn’s southern pole, and it spins in the same direction as that of a southern hemisphere hurricane on Earth. However, the hurricanes on Earth begin in the tropics and drift around. The polar hurricanes on Saturn are locked to their poles.

The bright clouds form a tightly wrapped spiral that traces a path toward the center as one follows it in a counterclockwise direction. This spiral could be a wave or actual particle motion toward the center from a disturbance further out. Or it could be the remnants of a compact cloud that got sheared apart by the higher angular velocity closer to the center. Choosing among these possibilities is the subject of ongoing research.

NASA also has a great little video of this massive, freakishly shaped hurricane here.

Source: NASA's Cassini mission.

Amazing astro-porn thanks to NASA - no Photoshop here.

Hubble captures a comet in the same frame as Mars:


Sunspot group on the Sun that's bigger than Jupiter:


The Sun in hydrogen-alpha, from NASA's Solar Dynamics Observatory:


For reference about that sunspot group:


Science is awesome.

Two of the mightiest gods in our sky will rise from the same starry bed tomorrow morning, so close their beaming faces will shine almost as one! Check out these Sky & Telescope shots:

Click the image to see the story at Sky & Telescope online.

Planets pair up every so often, but rarely is their dance so intimate. During Venus and Jupiter's embrace shortly before dawn tomorrow (Monday, August 18), they'll be separated by only 1/3° or less - that's thinner than your pinky at full-arm extension. It's the very best planet hookup of the year, and the closest pairing these two have had this century. Here's what they'll look like in binoculars or through a telescope using a low-power eyepiece:




Their tight dance will be brief. Each morning, Jupiter rises a little higher from his eastern bed and Venus lingers a little longer near ol' Sol. The bed they share tomorrow morning is M44, the Beehive Cluster, which will reward augmented viewing:



If you're up before dawn, don't forget to look east toward sunrise and watch two of the brightest planetary bodies embrace!
*
Writing update: Finished my second story in the "Jupiter Whispers" series (which will one day join to form a novel). This one's called "Orpheus' Engines," at least for now, and tallies up to almost exactly 7000 words. Turned out way more econo-political than I'd expected! Chock-full of alien and human communication issues, with lots of Jupiter imagery to set the mood.

Finally, while we're on the topic of Jupiter, how about some bonus photos! First a gorgeous animated gif of the planet rotating:


Click the image to see the Astronominsk page full of more great shots like this.

Finally, check out this amazing 3D animated gif! Put on those old blue-red 3D glasses if you have 'em to enjoy the full effect:


Click the image to see the Astronominsk page.

Enjoy!

Chris

Just wow:









We live in an age when one can make animated gifs of the daily sky ON MARS.

Chris

Aboard the ISS, Japan Aerospace Exploration Agency astronaut Koichi Wakata just captured and shared this otherworldly photo of the crescent Moon rising from Earth's atmosphere:


Click the image to see the NASA page.

This is not a false-color image: The gas and dust in each layer of the atmosphere act as prisms, filtering out certain wavelengths of light. You can't really get a view like this from Earth (well, for a lot of reasons, but that's one.) Here's another shot of a moonrise from space, taken by astronaut Ron Garan in 2011:


Click the image to see Ron Garan's Twitpics page.

Happy moonrise Friday!

Chris

Notice I don't call it "vacation," and here's why. On the other hand, it sure was a nice break to not have to be "on" for classes all week!

• I've been writing several mornings, every week since mid-December. Completely revised the opening scenes of The Galactic Adventures of Jack & Stella, completely re-envisioned how I'm handling POV (which means significantly rewriting every single other scene, too), wrote many more notes for future scenes, and cut thousands of words while writing thousands more... I've passed a total of 44k words, which means it's more than half-way done (based on a projected 70k)!

• Finished updating all three syllabi and Blackboard sites (that's the web interface for KU courses) for my spring semester classes. Sent all the students links to where their syllabi live online. HOORAY! Good lord, is it just me or does it take everyone most of a day to do this for each course?


• Worked a bunch on the hot-rod Newport, including rebuilding the broken valvetrain; finishing installing the new fuel-injection system; installing half the custom exhaust (with electric cut-outs for added raucousness on demand!); designing a crankcase-ventilation system that won't put so much smoke into the intake and getting started installing that; and finding a great deal on a new front-drive system that'll upgrade the alternator to handle fuel-injection duties, the A/C and power-steering pump to something that works, and convert it to a simpler serpentine-belt system that'll make it more reliable and more efficient - oh, and it's all polished aluminum, so it's much lighter and really pretty, too. ETA for street duty: a week or two! Assuming something else doesn't blow up....


• Did a bit of work on the Chevelle, but I want to get the Newport mobile, washed, waxed, and covered before really diving into this project; picked up some more parts I'll need, though. ETA for street duty: Late spring.


• Rewired a cool vintage ceramic lamp and installed it in the ceiling of my living room. MUCH nicer than the old (light-free) ceiling fan that used to clutter up the space:

• Did a bunch of updates on the Center for the Study of Science Fiction's website, and planned much more. Oh, and we're working with a major donor right now who's intending to support not only a full-ride scholarship for the summer Workshops, but also something even bigger for a student coming to study SF during the regular semester. Details to come....


• Started reading for the John W. Campbell Memorial Award for best SF novel. Loving everything so far, which is great, but could also be trouble come decision time....


• Got back into astronomy, with a new (to me) 100mm f/9 apochromatic refractor. WOWEE, does it provide gorgeous images! This is my first apochromat, a type of refractor that uses varying types of rare-earth glass to produce lovely, sharp, and color-free images. On a really nice German equatorial mount with dual-axis drives and a handy through-the-polar-axis North Star finder:

• Resumed a regular, hardcore workout schedule at the gym. Tried the beautiful-but-useless fancy fitness center here at KU (Ambler), because it was free to staff & faculty last week; we usually use beat-up, old, and dingy - but free - Robinson, because of its really useful and large free-weights room, and only visited crowded Ambler that once.


• Oh, and on a related note: Not to sound braggy or anything, but over Break the awesome Clevermanka started giving me regular, multi-hour massages at least once a week, sometimes EVERY DAY. OMG, I am so lucky.

Other stuff, too, like watching the new BBC Sherlock series! (Which starts on PBS tonight.) LOVE IT SO MUCH.

What did you do over the past month, whether or not you got a break?

Best,
Chris

"" (Watch on YouTube)

Apollo 8, the first manned mission to the Moon, entered lunar orbit on December 24, 1968 - Christmas Eve. That evening, Commander Frank Borman, Command Module Pilot Jim Lovell, and Lunar Module Pilot William Anders made this then-live television broadcast from lunar orbit, during which they showed pictures of the Earth and Moon as seen from Apollo 8. Later, they took the first Earthrise photo:


Click the image to see the excellent Wikipedia article (with lots of great photos).

( click for transcript )

Go here to learn more about the Apollo missions.

Merry Christmas!