NASA / JPL-Caltech / SSI

Two of Saturn's more than 60 moons join the ringed planet in this scene, captured by the Cassini orbiter on Jan. 19 and released on April 30. Tethys appears as a small white dot above the rings on the far left of the image. Enceladus appears as a smaller bright speck beside the planet. The rings cast wide shadows on the planet's southern latitudes.

Two of Saturn's moons are dwarfed by the giant planet and its rings in this family portrait from the Cassini spacecraft, which will mark its eighth year in Saturnian orbit in July. This image was put out by the Cassini imaging team on Monday, just a little too late to make our Top 20 roundup for the Month in Space Pictures — but it's worth passing along as a bonus prize.

You can see 660-mile-wide Tethys as a white dot toward the left edge of the image, and 313-mile-wide Enceladus as a smaller bright speck beside the planet. Tethys is thought to be composed mostly of water ice with a bit of rock mixed in, while Enceladus is a very special case: Cassini has repeatedly documented geysers of water ice spewing from fissures in that moon's surface — suggesting that liquid water and perhaps even living things may lie beneath. It'll be up to a future probe to plumb the mysteries of Enceladus more deeply.

Saturn's rings are seen nearly edge-on, and in this picture they're casting wide, curved shadows on Saturn's southern hemisphere. Bad Astronomy's Phil Plait says he can't help noticing the thin white ribbon of clouds stretching across the planet's northern hemisphere. Those may be the remnants of a monster storm that wrapped itself around the globe for months, starting in late 2010. "Our gas giants don't screw around," he writes. "When they do something, they do it big."

And when we do the Month in Space Pictures slideshow, we do it big as well. Click on the image below to see some of the best out-of-this-world views from the month of April. You'll find shots from the final flights of the shuttles Discovery and Enterprise, photos of weird phenomena on Mars and Uranus, and even a UFO (Galaxy, that is). If you want to find out more about the stories behind the pictures, leave a comment and I'll try to point you in the right direction.

Slideshow: Month in Space: A blaze of glory

NASA/SDO/AIA

Click through a solar eruption, the final odyssey of the shuttle Discovery and other outer-space highlights from April 2012.

Launch slideshow

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

NASA / JPL-Caltech / SSI

A plume of water ice is backlit as it spews from the south polar region of Enceladus, one of Saturn's moons. The image was taken in visible light with the Cassini spacecraft's narrow-angle camera on Feb. 20, from a distance of about 83,000 miles (134,000 kilometers).

NASA's Cassini mission has delivered a dark but dramatically backlit view of "Spaceship Enceladus": an icy moon of Saturn with geysers of water ice spewing from its south polar region, as if it were turning on its thrusters.

Enceladus isn't going anywhere, of course, but the geysers have launched a lot of speculation about what might be giving rise to the spray. Is water from a hidden ocean welling up through the cracks known as "tiger stripes"? If so, what creatures might lurk in that subsurface sea?

The picture released today by Cassini's imaging team fires up the imagination, even for team leader Carolyn Porco. "Now try to tell me Enceladus isn't the coolest, most fascinating moon there is!" she said in a Twitter update touting the view.

Really? But what about Europa, an icy moon of Jupiter that is also thought to harbor a subsurface ocean, and perhaps life. A probe to study Europa is high on NASA's list of future big-ticket missions, even though such missions are currently on hold due to budgetary constraints. (There's also some recent research suggesting that Europa's hidden ocean might be too acidic for life as we know it.)

Porco made her preference plain in a volley of tweets: "Enceladus, with the most accessible habitable zone beyond Earth, is far better for discovering anything about life than Europa."

NASA is said to be planning a concept study for an eventual Enceladus mission, although tight budgets may force a change of plan. The German Aerospace Center recently unveiled a study project known as Enceladus Explorer, or EnEx, which is looking at the possibility of putting a base station on the moon's surface and drilling down into the ice. The concept calls for a type of probe known as an IceMole to melt its way down to a water crevasse, retrieve a sample of liquid water and analyze it for the presence of microbes.

EnEx's collaborators have been testing a prototype IceMole on Switzerland's Morteratsch Glacier, and they're planning to try it out on glaciers in Alaska and Antarctica, leading up to the sampling of a subglacial lake in Antarctica in 2014. If those tests are successful, the team will propose sending IceMoles to Mars and eventually to Enceladus.

Enceladus isn't the only star of this week's Saturnian show. Fresh pictures of Saturn's second-largest moon, Rhea, were released as well. These pictures were captured over the weekend during a flyby that brought Cassini within 26,000 miles (42,000 kilometers) of the heavily cratered moon. NASA says the flyby was "relatively distant" but well-suited for global geologic mapping.

NASA / JPL-Caltech / SSI

This raw, unprocessed image of Rhea was acquired by the Cassini spacecraft on Saturday and received on Earth on Sunday. The camera was pointing toward Rhea from a distance of about 26,000 miles (41,873 kilometers).

NASA / JPL-Caltech / SSI

This raw image of Rhea was taken on Saturday from a distance of about 26,000 miles (42,096 kilometers). The pattern of lines on the right side of the image is the result of data loss during transmission.

The next big flyby is scheduled for March 27, when Cassini is due to come within 46 miles (74 kilometers) of Enceladus. That's close enough to sample those plumes of ice directly — and perhaps take one more step toward unraveling the mystery of Enceladus' hidden seas.

More about Enceladus, Rhea and Cassini:

• New images reveal Enceladus' icy secrets
• See what's hot on Enceladus
• Rhea and Titan line up in photo
• Greatest hits from Cassini

NASA / JPL-Caltech / SSI

Saturn's rings stretch in front of the moons Titan and Tethys in a Dec. 7 image captured by NASA's Cassini orbiter.

What do you get when you cross the rings and moons of Saturn? That sounds like the set-up for a joke, but for the team that processes the pictures from NASA's Cassini orbiter, the answer is totally serious: You get stunning images of the moons' interplay with the giant planet's rings.

The picture above, released today, shows Saturn's rings nearly edge-on, in front of the moons Titan (left) and Tethys (right). Cassini's narrow-angle camera captured the view on Dec. 7, 2011, as it was flying by a distance of about 1.4 million miles from icy Tethys (TEETH-iss) and 1.9 million miles from smog-covered Titan.

Last week the Cassini imaging team released another stunner snapped on the same day, showing tiny Tethys (660 miles wide) near the center of Saturn's disk, just below the ring plane.

Cassini was so close to Saturn's equator that the rings look like little more than a straight line, but you can see the delicate shadows of the rings stretching across the planet's sunlit disk into darkness. When Cassini's wide-angle camera took this picture, Tethys was about 1.1 million miles away.

Saturn, with a diameter of 74,900 miles, overwhelms Tethys in size. But the gas giant's density is such that it could float in water — that is, if there were a body of water big enough for it to float in. Does that mean Saturn could take a bath? Yes ... but it might leave a ring.

NASA / JPL-Caltech / SSI

The Saturnian moon Tethys is dwarfed by the ringed planet's disk in this Dec. 7 picture from the Cassini orbiter.

More imagery from Cassini and other space probes:

• Holiday goodies from deep space
• Saturnian storm goes wild
• Greatest hits from Cassini
• Year in Space Pictures 2011

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding the Cosmic Log Google+ page to your circles. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

NASA / JPL-Caltech / SSI

Saturn's northern storm marches through the planet's atmosphere in the top right of this false-color mosaic from NASA's Cassini spacecraft.

"Over the past year, a great disquiet has swept across the face of Saturn..." It sounds like the beginning of a science-fiction movie, but it's actually the latest missive from Carolyn Porco, head of the imaging team for the Cassini mission to Saturn. Today, Porco and her colleagues presented a visual chronicle of the largest Saturnian storm in more than a decade.

The storm was first noticed almost a year ago, as a spot near the line between day and night on the northern hemisphere. Since then, it's grown into a wide, bright band stretching around the entire planet.

"With a 200-day interval of intense, hissing convection, it holds the record as the longest-lasting Saturn-encircling storm ever," Porco writes. "And it has become the largest by far ever observed on the planet by an interplanetary spacecraft, giving us an unparalleled opportunity to study in great depth the subtle changes on the planet that preceded the storm's formatin and the mechanisms involved in its development."

The imaging team has bumped up the colors on a few of the images, like the one shown above, but the true-color images taken over the course of the past year tell a story that's just as dramatic.

NASA / JPL-Caltech / SSI

Images from Cassini show the evolution of a giant Saturnian storm over the course of months.

It's been 14 years and a month since Cassini was launched, and for seven and a half years it's been observing Saturn and many of its 60-plus moons. That puts Cassini right up there with the Mars rovers among NASA's most successful interplanetary missions. "And with any luck, there'll be a great deal more to come," Porco writes.

More from Cassini:

• Rounding up Saturn's moons
• Saturnian moons merge into a quintet
• A double scoop of Saturn's moons
• It's a Saturnian moonapalooza!
• Happy holidays from Saturn's moons
• Slideshow: Cassini's greatest hits

Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding me to your Google+ circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

NASA

Images of Saturn's moons made with the Cassini orbiter, shown here in an artist's conception, have been used to make a Flash-based golf game.

Now that the space shuttle has safely launched for its last time, it's time for space enthusiasts to have a little geeky fun: A virtual round of golf on Saturn's moons.

The Flash game, Golf Sector 6, was developed by Diamond Sky Productions, which is headed up by Carolyn Porco, the imaging science team lead for the Cassini spacecraft in orbit around Saturn.

The game is based on the images captured by the spacecraft and allows players to get a feel for what it would be like to tee it up on a truly out-of-this world course.

To play, hold down the clicker on your mouse and point the green arrow in the trajectory you want your tiny human golfer to hit the ball. The longer the arrow, the harder the swing.

"Each of Saturn's moons has its own weak gravity, which should keep things interesting, so be sure to take that into account when you make your swing!" the team explains on the Ciclops website, where the game is housed.

"Just like golfing on Earth, the goal is to hit the ball into the hole — or in this case, the crater! — using the smallest number of swings."

Playing a round on the Saturn's moons also presents a simple lesson in physics: Each moon has a different gravity because they are different masses and sizes. The ball's trajectory follows Newton's gravity formula.

Playing golf in outer space is nothing new. Apollo 14 astronaut Alan Shepard famously hit a few golf balls on the moon in 1971.

Russian cosmonaut Mikhail Tyurin hit a foam ball with a six iron during spacewalk at the International Space Station in 2006.

Maybe now that NASA is putting its focus on human spaceflight beyond low-Earth orbit, an astronaut may someday get to hit a few balls on Saturn. For now, a virtual fore! will have to do.

Tip o' the Log to Lisa Grossman at Wired.

John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).

NASA's Cassini orbiter has captured another close-up view of the Saturnian moon Helene, clearing the way for a global map of the 20-mile-wide "ice queen."

The spacecraft got its latest look at the icy moon on Saturday from a distance of 4,330 miles (6,968 kilometers), more than a year after its closest-ever Helene flyby in March 2010. This time, the pictures provided sunlit views of the moon's Saturn-facing side, improving on last year's imagery. Taken together, these pictures will enable astronomers to finish a global map that could shed additional light on the grooved, pockmarked moon's impact history, NASA's Jet Propulsion Laboratory said in today's image advisory.

Helene sticks out among Saturn's more than 60 moons for a couple of reasons: First of all, it is gravitationally bound in the same orbit as another, much larger icy moon called Dione. This makes it one of four "Trojan moons" in the Saturnian system, along with Polydeuces (which is also bound to Dione) and Telesto and Calypso (both bound to Tethys).

Helene's surface also reveals a network of gully-like features that may have been created by landslides (or, in this case, dustslides or iceslides). Working up a detailed map of the moon should help astronomers get a better grip on the gullies' genesis.

For more about the latest flyby, check out this posting from the Planetary Society's Emily Lakdawalla. And for more about Saturn's moons, check out these recent reports:

• Scientists bid to float their boat on Titan's seas
• Enceladus sparks auroral show on Saturn
• Can you spot the Saturnian moons?
• A double scoop of Saturn's moons
• Slideshow: Cassini's greatest hits

You can connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. Also, give a look to "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA's Cassini spacecraft has been snapping stunning pictures of Saturn and its moons since 2004, allowing scientists to probe the ringed planet and its spheres like never before.

Now, Chris Abbas, a designer and director at Digital Kitchen in Seattle, Wash., has grabbed hundreds of the images and compiled them into this mesmerizing video set to music by Nine Inch Nails. Rings spin, the planet floats, stars and moons whizz by. 

"I truly enjoy outer space," Abbas writes on the Vimeo website where the video is posted. "It's absolutely amazing that we now have the ability to send instruments out into the void of the universe to observe all sorts of interesting things."

To learn more about Cassini, check out NASA's mission website. More stories about the spacecraft and its discoveries are at the bottom of this post. Before you scroll down, however, there's one more bit of space-geek artistry to watch today.

This video, produced by astronomy graduate student Alex Harrison Parker from Canada's University of Victoria, gives a feel for what supernova — exploding, dying stars — sound like when hooked up to a grand piano or standup bass.

More information on how it was made and what it means is available from Discovery News.

More stories on Cassini and supernovae:

• Cassini zooms past two Saturn moons
• Saturn probe sends stunning ring views
• Cassini sees through Saturn's rough and tumble rings
• Cassini image confirms liquid on Saturn moon
• Saturn lightning superbolts revealed
• 10-year-old Canadian girl discovers a supernova
• Scientists identify brightest supernova
• Did supernova mark 17^th century King's birth?