Vega Has a Neptune?

The BBC News and EurekAlert are pretty excited about a discovery at Vega, the sapphire-blue star that hangs overhead in summertime (from the Northern Hemisphere; Aussies see it at the horizon).  Astronomers think they see a clump of material that might be at the distance from the star similar to Neptune’s distance from the sun.  […]

Ring Around the Moons

51; Saturn is known for its rings, and some small moons have been found inside its rings.  But wouldn’t it be strange if some of its moons had rings of their own?  Such a thing had not been widely considered before 2007, when there was a tentative detection of a ring around Rhea (see 03/10/2008).  […]

Planets and Moons Suddenly Got Much Younger

A planet or moon covered with craters just looks old, doesn’t it?  Planetary geologists have long relied on crater counts to estimate the absolute ages of surfaces, such as on the moon, Mars, Europa, and every other solid body.  Lots of craters meant old.  Few craters meant young.  Presumably, impacting bodies came in like clockwork […]

Questioning Earth’s Privileges

51; Two articles this week downplayed considerations that would make the Earth seem like a special place in the universe.  Both have ties to NASA.     Are life-friendly stars limited to a narrow band in the galaxy called the Galactic Habitable Zone (GHZ)?  NASA-supported Astrobiology Magazine cast doubt on the idea.  Citing a study […]

A “Completely Different Slant” on Solar System Formation

51; “Did great balls of fire form the planets?” New Scientist asks.  A new theory “challenges the notion that the solar system started out as a placid sea of dust motes which simply clumped together to form planets.” If accepted, it “puts a completely different slant on what happened in the early solar system in […]

Hiding Comets Out of Bounds

51; There’s a new theory floating around about where most of the comets came from: other stars.  For many years, astronomers hid them in an unobservable region called the Oort cloud that was assumed to be partly a remnant of the sun’s primordial disk, and material that was ejected outward.  Now, according to the BBC […]
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