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Community => Recreation Commons => Our researchers have made a breakthrough! => Topic started by: gwillybj on February 11, 2017, 06:13:11 pm

Title: This Asteroid Is So Small, It Could Fit In Your Living Room
Post by: gwillybj on February 11, 2017, 06:13:11 pm

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This Asteroid Is So Small, It Could Fit In Your Living Room
At 2 meters in diameter, it's a small, bright piece of natural space debris.
By Nicole Kiefert  |  Published: Wednesday, November 30, 2016

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NASA/JPL-Caltech

Astronomers in Arizona observed the smallest near-Earth asteroid ever characterized, a 6.5 foot (2 meter) diameter asteroid smaller than most cars. 

This asteroid, called 2015 TC25, also reflects 60 percent of light that falls onto it, making it not only the smallest asteroid, but also the brightest near-Earth asteroid.

2015 TC25 was discovered last October by a team led by assistant professor as the University of Arizona’s Lunar and Planetary Laboratory Vishnu Reddy, Lowell Observatory, and Northern Arizona University using Earth-based telescopes. Last year’s discovery was published this month in the Astronomical Journal (http://iopscience.iop.org/article/10.3847/0004-6256/152/6/162/meta;jsessionid=BB049F47A117656DFD77C3AB309ADB0F.c1.iopscience.cld.iop.org).

The team found 2015 TC25 using Lowell’s 4.3-meter Discovery Channel Telescope, NASA’s Infrared Telescope Facility, and the Magdalena Ridge Observatory 2.4-meter telescope. Using these resources, they found out that the asteroid has a rotational period of 2.23 minutes along with its irregular shape.

Reddy said in a press release (https://lowell.edu/arizona-based-astronomers-characterize-smallest-known-asteroid/) that new observations show the asteroid’s surface is similar to aubrites, a highly reflective meteorite made of bright minerals. Aubrite is typically formed in oxygen-free environments at extremely high temperatures and are fairly rare; One out of every 1,000 meteorites, to be exact.

“This is the first time we have optical, infrared, and radar date on such a small asteroid, which is essentially a meteoroid,” Reddy said in a press release. “You can think of it as a meteorite floating in space that hasn’t hit the atmosphere and made it to the ground – yet.”

Reddy believes 2015 TC25 was probably chipped off of its parent, 44 Nysa, by impact from another rock.

Stephen Tegler, co-author of the study and professor in the Department of Physics and Astronomy at Northern Arizona University, said in a press release it’s important to study near-Earth asteroids because of the threats they can pose to us.

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http://www.astronomy.com/news/2016/11/what-is-the-smallest-asteroid (http://www.astronomy.com/news/2016/11/what-is-the-smallest-asteroid)

Title: Re: This Asteroid Is So Small, It Could Fit In Your Living Room
Post by: gwillybj on February 11, 2017, 06:19:44 pm

https://en.wikipedia.org/wiki/Aubrite

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Aubrites are a group of meteorites (https://en.wikipedia.org/wiki/Meteorite) named for Aubres, a small achondrite meteorite that fell near Nyons (https://en.wikipedia.org/wiki/Nyons), France (https://en.wikipedia.org/wiki/France), in 1836. They are primarily composed of the orthopyroxene (https://en.wikipedia.org/wiki/Orthopyroxene) enstatite (https://en.wikipedia.org/wiki/Enstatite), and are often called enstatite achondrites (https://en.wikipedia.org/wiki/Achondrite). Their igneous (https://en.wikipedia.org/wiki/Igneous) origin separates them from primitive enstatite achondrites and means they originated in an asteroid (https://en.wikipedia.org/wiki/Asteroid).

Aubrites are typically light-colored, and with a brownish fusion crust. Most aubrites are heavily brecciated. It's often said that they look "lunar" in origin.

Aubrites are primarily composed of large white crystals of the Fe-poor, Mg-rich orthopyroxene, or enstatite. Around this matrix, they have minor phases of olivine, nickel-iron metal, troilite, which indicate a magmatic formation under extremely reducing conditions. The severe brecciation (https://en.wikipedia.org/wiki/Breccia) of most aubrites attests to a violent history for their parent body. Since some aubrites contain chondritic xenoliths it is likely that the aubrite parent body collided with an asteroid of “F-chondritic” composition.

Comparisons of aubrite spectra to the spectra of asteroids have revealed striking similarities between the aubrite group and the E-type asteroids (https://en.wikipedia.org/wiki/E-type_asteroid) of the Nysa family. A small Near-Earth object (https://en.wikipedia.org/wiki/Near-Earth_object), (3103) Eger (https://en.wikipedia.org/wiki/3103_Eger), is also often suggested as the parent body of the aubrites.