What's going on inside a gas giant?

Sending spacecraft in to investigate is a risky proposition—the deeper you go, the higher the heat and pressure, so you'd be burned up and/or crushed before you got far enough to record much.

But thanks to various probes and telescopes operating at safer depths, we know a good deal about the gas giants' chemistry, heat patterns, and surface weather, as well as how these types of planets likely formed in the early days of the solar system.

One of the outstanding mysteries, however, is why gas giants such as Saturn seem to be giving off more light than they should based on the heat they're getting from the sun.

In a new paper in this week's PNAS, a team of scientists fed a bunch of observational data into some supercomputers and ran a couple different scenarios for density, temperature, and composition within Saturn.

Based on their results, we can now say with some certainty that, deep inside, Saturn is made of white and yellow Styrofoam.

—Picture by Kwei-Yu Chu, courtesy LLNL

Uh, wait a minute.

Jamieanne Hassler of Indianapolis! This self-described cupcake addict baked up an amazingly creative version of Jupiter that, well, takes the cake in our Planetology cupcake contest.

It really has been Jupiter's lucky week so far: a new orbiter, an intriguing new study of its core, and now a sweet homage in the form of a decadent chocolate-chili cupcake. Have a look, and send virtual handclaps to Jamieanne for her winning creation:

I'm hungry for some gas giant goodness ...

In Jamieanne's own words: These are Jupiter cupcakes. The cake is chocolate with a kick of cayenne pepper to represent the heat of Jupiter's core [no kidding! Jupiter's core is estimated to be around 55,000 degrees F, or 30,000 degree C], and the center of the cupcake is filled with a soft whipped cream to represent the many layers of clouds on Jupiter. The frosting is a cream cheese/chocolate buttercream swirl in colors similar to Jupiter's. Hanging above the Jupiter cupcakes are the 4 Galilean moons of Europa, Ganymede, Io and Callisto, formed from homemade playdough.

Recipe

*Chocolate cupcakes
Makes 12

Ingredients

• 1/4 cup + 2 tablespoons unsweetened cocoa powder


• 3/4 cup all-purpose flour


• 3/4 cup sugar


• 3/4 teaspoon baking soda


• 1/2 teaspoon baking powder


• 1/2 teaspoon salt


• 1/4-1/2 teaspoon cayenne pepper (use more or less to suit your taste)


• 1 large eggs


• 1/4 cup + 2 tablespoons warm water


• 1/4 cup + 2 tablespoons buttermilk


• 1 tablespoon + 1 1/2 teaspoons vegetable oil


• 1/2 teaspoon vanilla extract

Preheat oven to 350 degrees. Line cupcake pans with liners; set aside. In a large mixing bowl, sift together cocoa, flour, sugar, baking soda, baking powder, salt and cayenne pepper. Add the eggs, warm water, buttermilk, oil, and vanilla; mix batter until smooth, about 3 minutes. Scrape down the sides and bottom of bowl to assure batter is well mixed.

Divide batter evenly among liners, filling each about one-third full. Bake until tops spring back when touched, about 20 minutes, rotating pan once if needed. Transfer to a wire rack; let cool completely.

*Whipped cream filling
Makes about 1 cup

Ingredients

• 1/2 cup heavy whipping cream


• 2 teaspoons sugar


• 1 teaspoon vanilla extract

Chill stainless steel bowl and whisk attachment of an electric mixer in freezer for about 10-20 minutes. Combine all ingredients in steel bowl and use whisk attachment at high speed until stiff peaks form. Fill
cupcakes when the cupcakes are completely cool.

*Cream cheese frosting
Makes enough for 1-2 dozen cupcakes

Ingredients

• 8 ounces cream cheese, softened and cut into small pieces


• 3 tablespoons unsalted butter, softened and cut into small pieces


• 3/4 teaspoon vanilla extract


• 2 1/2 cups sifted confectioners' sugar

In a large bowl, on the medium speed of an electric mixer, beat the cream cheese and butter until smooth, about 3 minutes. Add the vanilla and beat well. Gradually add the sugar, 1 cup at a time, beating continuously until smooth and creamy. Cover and refrigerate frosting for 2-3 hours, but no longer, to thicken before using.

*Chocolate buttercream
Makes about 1 cup

Ingredients

• 1/4 cup unsalted butter


• 1/3 cup unsweetened cocoa powder


• 1 1/2 cups confectioners' sugar


• 2 tablespoons + 2 teaspoons milk


• 1/2 teaspoon vanilla extract

Melt butter. Stir in cocoa powder. Alternately add powdered sugar and milk, beating to spreading consistency. Add small amount of additional milk, if needed. Stir in vanilla.

To make swirled frosting, spoon an amount of each color individually into a piping bag so that the colors are side by side. Squeeze out the frosting over a bowl first until all the colors start coming out, then start swirling!

Whew! Egypt = amazing. I can't even begin to describe the wonder and awe of standing inside a pyramid or walking the Avenue of the Sphinxes or sailing in a felucca on the Nile. It really is something everyone should do at some point in their lives.

The best part is that it seems I bear some resemblance to an Egyptian soap star, and had many requests to have my picture taken with people at the sites we visited. So much for my attempts to blend in to the crowd ...

—Photo by Jon Pearse

But enough about moi, it's Planetology day! The book is now officially released, and lucky me got to chat with the authors, astronaut Tom Jones and planetary geologist Ellen Stofan, about their careers, their passions, and their extensive knowledge of planets.

What follows is a pared-down version of our conversation for your reading pleasure.

And don't forget, there's still time to submit a recipe for the solar system cupcake contest. The winner gets their recipe published here and a copy of Planetology sent to them—so get baking!

Next week me and my mummy are off to visit Egypt, a trip I've been looking forward to for more than a year. Sadly, our jam-packed itinerary doesn't include much computer time, so blogging from the field is not an option.

A guard watches over statues of Ramses II in Abu Simbel
—Photo by David Boyer/NGS

Never fear. For the next two weeks I leave you in the very capable hands of my two colleagues, Stephen and Susan.

Stephen Mather is the science and environment producer for nationalgeographic.com.

He tells me that his favorite planet is Venus, and that he has been known to build and launch—but rarely retrieve—model rockets. He'll be keeping up with the latest planet news as well as reporting on a fun new project from National Geographic magazine that will launch next week, so stay tuned!

Susan Poulton is the vice president of programming and production for nationalgeographic.com and a familiar face at space shuttle launches.

She'll be keeping readers abreast of the latest developments leading up to the November 14 launch of the space shuttle Endeavour, which is headed to the ISS to deliver some new household goods, make a few repairs, and switch out a member of the crew. Susan will even be live blogging from the launch site—a first for Breaking Orbit.

A Soyuz spacecraft carrying crew headed for the ISS blasts off the Baikonur Cosmodrome in Kazakhstan on October 12, 2008
—Photo courtesy NASA/Bill Ingalls

Just about every house has a room where projects go to die.

The old computer that you were going to refurbish and give to charity, that set of fabric swatches that were meant to be a quilt, your brief and ill-advised fling with oil painting—all the remnants of things that could have been, but were instead swept into a less-traveled area and left to mingle and collect dust.

In our solar system, the junk room is the main asteroid belt, a region between Mars and Jupiter full of pieces that could have been planets.

Thanks to mighty Jupiter's gravity, those pieces of rocky and metallic debris just won't coalesce into planets, leaving us with plenty of fodder for the next doomsday scenario.

Now it turns out that our closest stellar neighbor, a sunlike star called Epsilon Eridani, has not one asteroid belt, but two: one in roughly the same spot as our belt and another about as far from the star as Uranus is from the sun.

—Image courtesy NASA/JPL-Caltech

—Image courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

NASA's MESSENGER space probe sent some postcards home this morning from its second jaunt past Mercury, that tiny planet nearest to the sun.

The flyby is part of some maneuvering MESSENGER has to do to ease itself from orbiting the sun to orbiting Mercury.

Using the gravity of other planets helps the orbiter reach Mercury while saving on fuel, a bit of technique that was not even feasible until the 1980s.

—Image courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

NatGeo News reporter Anne Minard has the skinny on what scientists are saying about the new images, including the implication that geologic processes on Mercury might be an awful lot like those on the moon.

Minard also collected a great set of facts and figures about Mercury and its exploration that didn't make the cut for the news story, but that I think deserve a bit of airtime:

• Mercury has a metal-rich core 60 percent denser than Earth's.
• The planet's thin atmosphere is contains sodium, calcium, potassium, and, surprisingly, water vapor.
• Mercury's daytime surface temperatures can reach over 800 degrees Fahrenheit (426 degrees Celsius), but it looks like the planet still manages to have ice in some of its craters.
• Mariner 10 flew by Mercury three times in 1974 and 1975, capturing images of about 45 percent of the planet's cratered surface.
• MESSENGER launched on August 3, 2004. It carried about 1,323 pounds (600 kilograms) of liquid chemical propellant at launch, nearly 55 percent of its total launch weight.

• The spacecraft conducted an Earth flyby in 2005 and two Venus flybys in 2006 and 2007 on its way to Mercury.
• MESSENGER first flew by Mercury in January of this year, imaging a further 20 percent of the surface.
• On its second flyby, MESSENGER flew 124 miles (200 kilometers) above Mercury's surface during its closest approach on October 6, 2008.
• The craft imaged 30 percent of the surface not seen during previous space-based missions.
• As of today [October 7, 2008] MESSENGER is about 61million miles (99 million kilometers) from Earth.
• The craft is halfway through a 4.9-billion-mile (7.9-billion-kilometer) journey into Mercury's orbit that includes more than 15 trips around the sun.

—Image courtesy NASA

The tug-of-war between space-based and ground-based telescopes continues, with today's release of what's being called the sharpest full-planet image of Jupiter taken by an on-the-ground observatory.

—Image courtesy ESO

[versus]

Jupiter, as seen by the Hubble Space Telescope in 2007
—Image courtesy NASA, ESA, and the Hubble Heritage Team (AURA/STScI)

An international team used the ESO's Very Large Telescope in Chile to stare right at Jupiter for almost two hours straight.

The resulting infrared image revealed that Jupiter has lowered its belt. The bulk of the haze within the bight band around Jupiter's midsection has migrated south by more than 3,700 miles (6,000 kilometers) since 2005, the researchers said.

"The change we see in the haze could be related to big changes in cloud patterns associated with last year's planet-wide upheaval, but we need to look at more data to narrow down precisely when the changes occurred," team member Mike Wong said in a press release.

[Incidentally, the global upheaval he's referring to involved massive changes in cloud patterns and other wild weather features observed in 2007.]

In an interview with NatGeo News reporter Richard A. Lovett, lead researcher Franck Marchis, a planetary astronomer at the University of California, Berkeley, and the SETI Institute, said of the new image: "We have something comparable to or even better than the Hubble Space Telescope."

Wow. But this isn't the first time researchers using ground-based 'scopes have compared their work to products of the aging but much beloved Hubble.

The planets (plus Pluto) in an approximate size, but not distance, comparison
—Image courtesy NASA/Lunar and Planetary Laboratory

The astronomy gods are giving me a pretty nice birthday present this year: a planetary reunion.

On December 1 at 7:36 p.m. ET, Venus and Jupiter will be in conjunction, the astronomical term for "really close together as far as observers on Earth are concerned."

If the skies are clear, stargazers will be able to see the planets shining just two degrees apart, with a partially lit moon sitting three degrees away from Venus.

The same two planets met up once before this year on the morning of February 1. They won't be in conjunction again until May 2011.

Even better from a fun coincidence point of view, for the December reunion the planets will meet in the constellation Sagittarius—my astrological sign.

It's brief and a bit blurry, but here's an animation of what the event should look like:

Of course, being in conjunction has nothing to with the actual distance between the planets.

Germany takes on the worlds this week, as the 3rd European Planetary Science Congress gets underway in Münster.

Today's cornucopia included a presentation from Gerhard Schmidt of the University of Mainz, who says that platinum rings come from outer space.

More precisely, the idea is that platinum, gold, and other precious "iron-loving" metals were stripped from the planet's superheated self as Earth formed, but then were delivered back to the exterior layers by asteroid impacts once things cooled down a bit.

The stony asteroid Kleopatra
—courtesy NASA

Schmidt was prompted to investigate the matter because the ratios of iron-loving metals in Earth's mantle are not quite in line with their abundances in meteorites known as chondrites—stony chunks of space rock thought to represent pristine material from the birth of the solar system.

His team calculates that 160 asteroids each about 12 miles (20 kilometers) across smashed into Earth roughly 20 to 30 million years after the core formed, depositing the metals in question onto our young planet.

The glitch with this theory is that even after 12 years of studying impact craters on Earth, along with bits of earthly, lunar, and Martian rock from impact sites, Schmidt and co. can't exactly match any known meteorites to the metal ratios found in Earth's mantle.

What's more, asteroids that might have the necessary ratios are predicted to come from the space between Mercury and Venus, but no known meteorites from this region have ever been found.

Still, it's an intriguing hypothesis, especially for someone like me who is always looking for the next geeky but decorative conversation piece.

If men are from Mars and women are from Venus, should we space-loving chicks be annoyed that the red planet gets so much more money and attention than its "feminine" counterpart?

Yeah, Mars is cool and all, what with its tantalizing geologic features and strong potential as a relatively recent host for liquid water.

By contrast, Venus seems so unwelcoming, shrouded in murky clouds of sulfuric acid that whirl at breakneck speed above a dusty surface hot enough to melt lead.

But underneath that hostile exterior lurks the most Earthlike planet we know of right now.

Luckily, while the U.S. is busy cheering on its army of Martian rovers, orbiters, and landers, the European Space Agency (ESA) has been sending out findings from a probe dubbed Venus Express that's been orbiting our "sister" planet since the spring of 2006.

Today ESA announced results from a study published back in July in the journal Geophysical Research Letters about the first 3-D map of venusian winds covering the entire southern hemisphere.

—ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA/ Universidad del País Vasco (R. Hueso)

Not every meteor that slams into Earth is a dino-killing whopper. Microscopic meteorites also find their way down to the planet's surface on a regular basis, but there's been some debate about where exactly they come from.

In the September 1, 2008, issue of Geology, Mathew Genge of Imperial College London reports that a massive collection of cosmic dust grains found in Antarctic ice originally came from the Koronis asteroids, an ancient family of space rocks in the Main Belt between Mars and Jupiter.

Koronis family asteroid 243 Ida and its moon, Dactyl
—NASA/JPL

The minerals and chemicals inside these itteh-bitteh pieces of asteroid match what scientists had previously found in a small group within the Koronis family called the Karin asteroids. And sure enough, telescope observations of the Karin show those rocks are even now jiggling around and smashing into each other, producing dust.

According to Genge, the discovery means that some level of research into the origins and formation of the solar system can be accomplished without even leaving the ground.

"Out of the cosmic dust, a planet is born."
—NASA/JPL-Caltech/R. Hurt (SSC)

"The answer to so many important questions, such as why we are here and are we alone in the universe, may well lie inside a cosmic dust particle," Genge said in a university news release.

"Since they are everywhere, even inside our homes, we don't necessarily have to blast off the Earth to find those answers. Perhaps they are already next to you, right here and right now."