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| ©Arecibo Observatory |
| 2001 SN263 has now been revealed as the first near-Earth triple asteroid ever found. - |
Science & Technology
Once considered just your average single asteroid, 2001 SN263 has now been revealed as the first near-Earth triple asteroid ever found. The asteroid -- with three bodies orbiting each other -- was discovered this week by astronomers using the radar telescope at the National Science Foundation's (NSF) Arecibo Observatory in Puerto Rico.
[On Tuesday, February 5], lost within the orange glow of the setting sun, a newly discovered asteroid passed within 84,000 miles of our planet, just a third of the distance to the Moon, and barely anyone noticed. A sharp-eyed skywatcher with a good pair of binoculars might have seen the unfamiliar object gliding silently through Aquarius. But did they know what they were seeing was a very unexpected asteroid? Would they have understood just how close it really was?
Near-Earth Object, 2008 CT1, was discovered only two days before [the] close pass by the Lincoln Near-Earth Asteroid Research project, an MIT project funded by the USAF and NASA committed to discovering space rocks that orbit near Earth. Using robotic telescopes located at New Mexico's White Sands Missile Range, the project has contributed nearly 70% of world-wide Near-Earth Asteroid discoveries since beginning operations in 1998.
Near-Earth Object, 2008 CT1, was discovered only two days before [the] close pass by the Lincoln Near-Earth Asteroid Research project, an MIT project funded by the USAF and NASA committed to discovering space rocks that orbit near Earth. Using robotic telescopes located at New Mexico's White Sands Missile Range, the project has contributed nearly 70% of world-wide Near-Earth Asteroid discoveries since beginning operations in 1998.
It hurtled through deep space and seared through the Earth's atmosphere, only to wind up as a child-friendly display.
A 379-pound nickel-iron meteorite made its debut this week at Kidspace Children's Museum, where it now occupies a prime spot in the museum's Boone Nature Exchange area.
The meteorite landed in Argentina and was discovered in 1570. It was donated to the museum by SuSan Nelson and Walter Witkowski.
A 379-pound nickel-iron meteorite made its debut this week at Kidspace Children's Museum, where it now occupies a prime spot in the museum's Boone Nature Exchange area.
The meteorite landed in Argentina and was discovered in 1570. It was donated to the museum by SuSan Nelson and Walter Witkowski.
AN EXCEPTIONALLY LARGE METEORoid storm was detected on the moon by the Apollo seismic network between 20 to 30 June 1975, attaining daily impact rates five to ten times larger than the normal steady rates [1]. The storm has been interpreted as arising from a meteoroid cloud with a diameter of 0.1 astronomical unit and a total mass of [10.sup.13] to [10.sup.14.g.] Duennebier et al. [1] have estimated that a total mass of fragments of about 1.8 X [10.sup.6] g collided with the moon during the event.
Astronomers have long stated that a large number of meteoroids frequently impact the Earth. Such incidents are rarely reported despite the enormous amount of energy released. However, newly-declassified documents show that secret military surveillance systems have been detecting such events.
Meteorites provide information about the formation of the Solar System. They are pieces of very old material that have fallen from space to the Earth. Most result from asteroid collisions in the Asteroid Belt between Mars and Jupiter, but over a dozen from the Moon and another 12 from Mars have also been identified. The three main types of meteorite are stone, iron, and stony-iron. Stony-iron meteorites are the rarest and are often quite beautiful. Antarctica is the best place to find meteorites because there the ice and aridity preserve them, sometimes for as long as a million years.
Each year approximately 40,000 tonnes of extraterrestrial material, most of it dust, bombards the earth. But where does it come from, and why does it land here?
Visitors from space arrive on the Earth with amazing frequency, not as alien monsters or little green people in flying saucers, but as meteorites, extraterrestrial material ranging from the tiniest of dust grains to enormous impact crater-forming bodies. Meteorites were formed at the birth of the Solar System, about 4,560 million years ago. We have no material on Earth this old, so it is only by studying meteorites that we can learn about the processes that shaped our Solar System and our planet.
Each year approximately 40,000 tonnes of extraterrestrial material, most of it dust, bombards the earth. But where does it come from, and why does it land here?
Visitors from space arrive on the Earth with amazing frequency, not as alien monsters or little green people in flying saucers, but as meteorites, extraterrestrial material ranging from the tiniest of dust grains to enormous impact crater-forming bodies. Meteorites were formed at the birth of the Solar System, about 4,560 million years ago. We have no material on Earth this old, so it is only by studying meteorites that we can learn about the processes that shaped our Solar System and our planet.
Secret data from military satellites in orbit thousands of miles above Earth show that the planet is continually bombarded by big meteoroids that explode in blasts the size of atomic detonations. The data, from spacecraft meant to watch for rocket firings and nuclear explosions, were declassified recently by the Defense Department and are to appear later this year in a book.
From 1975 to 1992, the satellites detected 136 explosions high in the atmosphere, an average of eight a year. The blasts are calculated to have intensities roughly equal to 500 to 15,000 tons of high explosive, or the power of small atomic bombs. Experts who have analyzed the data are publishing it in the book, Hazards Due to Comets and Asteroids, say that the detection rate is probably low and that the actual bombardment rate might be 10 times higher, with 80 or so blasts occurring each year.
From 1975 to 1992, the satellites detected 136 explosions high in the atmosphere, an average of eight a year. The blasts are calculated to have intensities roughly equal to 500 to 15,000 tons of high explosive, or the power of small atomic bombs. Experts who have analyzed the data are publishing it in the book, Hazards Due to Comets and Asteroids, say that the detection rate is probably low and that the actual bombardment rate might be 10 times higher, with 80 or so blasts occurring each year.
An international project to make the world's most productive ground-based telescope 10 times more capable has reached its halfway mark and is on schedule to provide astronomers with an extremely powerful new tool for exploring the Universe. The National Science Foundation's Very Large Array (VLA) radio telescope now has half of its giant, 230-ton dish antennas converted to use new, state-of-the-art digital electronics to replace analog equipment that has served since the facility's construction during the 1970s.
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| ©NRAO/AUI/NSF |
| VLA antennas getting modern electronics to meet new scientific challenges. |
Very young brains process memories of fear differently than more mature ones, new research indicates. The work significantly advances scientific understanding of when and how fear is stored and unlearned, and introduces new thinking on the implications of fear experience early in life.
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| ©iStockphoto |
| Very young brains process memories of fear differently than more mature ones, new research indicates. The work significantly advances scientific understanding of when and how fear is stored and unlearned, and introduces new thinking on the implications of fear experience early in life. |
A next-generation atomic clock that tops previous records for accuracy in clocks based on neutral atoms has been demonstrated by physicists at JILA, a joint institute of the Commerce Department's National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder. The new clock, based on thousands of strontium atoms trapped in grids of laser light, surpasses the accuracy of the current U.S. time standard based on a "fountain" of cesium atoms.
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| ©Greg Kuebler/JILA |
| JILA's strontium atomic clock is now the world's most accurate clock based on neutral atoms. |
