Reconstructing the orbit of the Chelyabinsk meteoroid
A pair of Colombian scientists has made the first attempt to figure out the meteoroid that exploded over Russia last month.
Asteroid Excavation: Probing the interior of Vesta through major impacts
The asteroid Vesta has been scared by two giant impacts, dredging up material from deep below its surface. New simulations of the impacts allow us to trace where the material should end up and creates a conflict between theory and observation.
Cleaning Up The Solar System
TITLE: A Search for Vulcanoids with the STEREO Heliospheric Imager AUTHORS: A. J. Steffl, N. J. Cunningham, A. B. Shinn, D. D. Durda, S. A. Stern FIRST AUTHOR’S INSTITUTION: Southwest Research Institute, BoulderThe recent evidence for an asteroid belt in the Vega system highlights how well we’re getting to know the solar systems around other stars. But there are some surprising gaps in our knowledge of our own. Inwards of the orbit of Mercury, there exists a dynamically stable region between about 0.21 AU and 0.07 AU where objects can orbit without being perturbed by Mercury or vaporized by the Sun. As far back as 1859 astronomers proposed that there might be at least one small planet lurking in this region, at the time a potential explanation for the odd precession of Mercury, and gave this hypothetical world the name “Vulcan”. Although Mercury’s orbital behavior was later explained by Einstein using general relativity, the idea of close-in planetesimals called “Vulcanoids” stuck around. The orbital motions of Mercury, Venus, and the Sun rule out a planet, but there’s still room for smaller objects. We now know that many, many exoplanet systems feature full-blown planets that orbit far closer in to their stars than Mercury does to the Sun. Why not some debris in ours?But how could something comparatively right next door go undetected for so long? Their very closeness to the Sun makes them hard to see. From Earth’s perspective, objects in the Vulcanoid region never stray farther than about 12 degrees from the Sun in the sky. From the ground they can only be observed in the early twilight, and...
An Improved Model for That Pesky Zodiacal Dust
The Solar System’s interplanetary dust (called zodiacal dust) can be a source of noise in infrared and optical observations, but it also holds information about the recent history of the Solar System. This new and improved model of the zodiacal dust reveals the relative contributions to the dust by asteroids, comets, and interstellar dust.
2012: My Favorite Doomsday Scenarios
Let’s be serious for a moment: nothing dire is going to happen on December 21st. Rest easy. But in celebration I’ve decided to count down my top five favorite astronomical doomsday scenarios, ordered from most to least plausible.
Astronomers like Easter egg hunts: studying a unique star system in the infrared
Astronomers like to find cool things. The first Earth-sized planet. The most distant galaxy yet. Two stars that merged while we watched. The coolness factor is certainly one reason why we keep at it – who wouldn’t want to be the first to find an Earth-sized planet, or the first human to see light from a galaxy that’s existed for billions of years? But there’s also a compelling scientific reason to search for these oddballs. This paper reports on the likely discovery of dust around a pair of binary stars.