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Results tagged “asteroids” from Breaking Orbit

Geminids to Be Outshone by Big, Bright Moon

Posted on December 11, 2008 | 1 Comments

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When it comes to sky shows, sometimes a lunar blessing can be a meteor's curse.

Friday night's biggest, baddest full moon is sure to capture the hearts of many a skywatcher. But it also means this year's Geminid meteor shower, due to peak the night of December 13-14, will be largely washed out by the satellite's shining face.

In recent years the Geminids have become the most active of the annual meteor showers, with peak rates of 110 "falling stars" an hour on record for 1996.

Last year's shower fell during a moonless night, prompting predictions of the "year's best" sky show for 2007.

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A Geminid meteor as seen from San Francisco on December 14, 2007
—Photo courtesy Mila Zinkova

Not so for 2008. Astronomers predict that during this year's shower only the brightest meteors will cut through the moon's glare, and the folks over at EarthSky are even suggesting would-be skywatchers should skip the frigid December vigil and wait for a clearer view of the Quadrantid shower in early January.

Die-hard fans may get lucky, though, especially if you can get away from city lights and recline in the weekend chill.

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Live Long and Prosper, Says Star With Two Belts

Posted on October 27, 2008 | 0 Comments

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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.

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—Image courtesy NASA/JPL-Caltech

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Mars's "Death Star" Moon Just a Pile of Rubble

Posted on October 16, 2008 | 0 Comments

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There's always a twinkle in a science writer's eye when real life imitates art.

In 2005 we had a snapshot of gases and dust around a star that seemed to be auditioning for the next Lord of the Rings film.

Then in 2007 there came the news that the universe could be packed with double-sunned planets like Star Wars' Tatooine.

Earlier this year a Mars orbiter sent in high-resolution shots of a body called Phobos, highlighting its massive Stickney Crater and its uncanny resemblance to the Empire's ultimate weapon.

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With apologies to Sir Alec Guinness, this time that is a moon—Phobos is the larger of the two known natural satellites orbiting Mars.

—Image courtesy NASA/JPL-Caltech/University of Arizona

Although it was discovered way back in 1877, Phobos has remained fairly enigmatic.

In the late 1950s, its odd orbit inspired Russian astronomers to suggest that the moon is a hollow shell, and an artificial one at that.

It took almost a decade to silence that offbeat theory, based on better calculations of the moon's orbit combined with new density measurements and eventually images from the Viking mission.

But Phobos still boasts some unusual characteristics, prompting much speculation about what the moon is made of and how it took up residence around Mars.

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Ich Liebe Planeten

Posted on September 22, 2008 | 0 Comments

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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.

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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.

Why's It so Dusty Down Here?

Posted on September 3, 2008 | 0 Comments

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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.

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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.

planet-dust.jpg

"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."

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About This Blog

The moon
From dwarf planets to hot Jupiters, join NatGeo News space and tech editor Victoria Jaggard in a global discussion about all things extraterrestrial.


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