Strange shapes in space

The shapes of bubbles and clouds in outer space demonstrate that physics can do some pretty bizarre things on a giant scale.

Take RCW 120, for example. The star-forming bubble, about 4,200 light-years away in the constellation Scorpius, is the subject of a European Space Agency picture celebrating the first anniversary of the Herschel space telescope's launch.

Radiation from a hot, massive star at the bubble's center is blasting gas and dust outward, and that's what has cleared out the space around the star. The central star doesn't show up well in Herschel's infrared image, but you can see it easily in this submillimeter-wavelength view from the European Southern Observatory's APEX telescope in Chile.

The shock wave from the central star compresses the material on the bubble's edge so much that still more stars are being squeezed into existence. In the Herschel image, you can see a particularly bright spot on the right edge of the bubble. That's an embryonic star that appears destined to turn into one of the brightest lights in our galaxy.

The Herschel science team calls it an "impossible" star because it's exceeding the theoretical limit for a star's mass.

"This star can only grow bigger," Annie Zavango, an astronomer at the Laboratoire d'Astrophysique de Marseille, said in the ESA's image advisory. "According to our current understanding, you should not be able to form stars larger than eight solar masses."

At about eight solar masses, the power of the newborn star should blast away any additional gas or dust before the extra mass has a chance to accumulate. But the star at the bubble's edge is already eight to 10 times as massive as the sun, and it's on track to get much larger.

Astronomers have already spotted stars that are as much as 150 times as massive as the sun, but they don't know exactly how they can get that large. A close study of the brightening light in RCW 120 could show them the way.

Stellar blasts can blow amazing bubbles in space. Perhaps the best-known blast is associated with Eta Carinae, a supermassive star that could go supernova one of these days.

Its double-lobed shape, reminiscent of an old-fashioned dumbbell, arises because the star is blowing material out from both poles.

Lots of stellar explosions take on this shape: The phenomenon has been attributed to several factors, including spin dynamics and the star's magnetic field.

Perspective plays a role as well: One famous example is the Red Rectangle, which looks like a quadrangle but is actually two back-to-back cones of material flowing out from a double-star system.

And then there's the hexagon on Saturn: The six-sided cloud pattern at the ringed planet's north pole has puzzled astronomers for decades, but now physicists have figured out the dynamics that can cause hexagonal features - as well as triangular, square and even seven-sided shapes as well. They can even create them in the lab.

Researchers from Oxford University produced the geometrical effects using a solution of water and glycerol in a tank that could be spun up to various speeds. Their findings were published in the journal Icarus last month, and this week Planetary Society blogger Emily Lakdawalla provided plenty of pictures and videos explaining the phenomenon.

Still more strange sights can be seen at the surface of our sun, as illustrated by the first big batch of photos from NASA's Solar Dynamics Observatory. One video clip shows a huge prominence looping up from the sun's surface and back down again. Another movie shows a wave of plasma rising up, then falling back down to the surface like "coronal rain."

The curling action occurs because of complex loops in the sun's magnetic field, as discussed by Discovery News' Ian O'Neill. Those loops help explain why the solar corona gets so much hotter than the actual surface of the sun.

The Solar Dynamics Observatory's perspective on the sun's sizzling loops is the top picture in our latest installment of the Month in Space Pictures. For more strange shapes, click your way through the curiosities on exhibit in msnbc.com's Space Gallery.

Follow the links below for bigger views and further background about the pictures in the latest Month in Space slideshow:

• Ring of fire (Solar Dynamics Observatory)
• Death Star in detail (Cassini)
• Double light show (Reuters)
• Galactic glory (Hubble Space Telescope)
• Polygon planet (Mars Reconnaissance Orbiter's HiRISE)
• The trail to space (Getty Images)
• Women at work (International Space Station)
• Window on the world (International Space Station)
• Out for a spacewalk (International Space Station)
• Beautiful backdrop (International Space Station)
• Happy 20th, Hubble (Hubble Space Telescope)
• Satellite spots oil spill (NASA Earth Observatory)
• Dark and light nebula (European Southern Observatory)
• Looking into the put (NASA Earth Observatory)
• Some like it hot (Spitzer Space Telescope)
• Special delivery (AFP - Getty Images)
• Dunes of Mars (Mars Reconnaissance Orbiter's HiRISE)

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