Geraldo was wondering if 2014 AA might have others following and the following is my comment.
- LRK -
------------------------------
Geraldo,
Let's hope not. The pictures taken that show this one, don't seem to show others with it. The sounds made from the burn up over the Atlantic had a couple of locations but very weak.
------------------------------
A sequence of four images, taken roughly 11 minutes apart, reveals the movement of asteroid 2014 AA when it was discovered in northern Orion early on January 1st (Universal Time). The 19th-magnitude object struck Earth 25 hours later.
Catalina Sky Survey / NASA
It was New Year's Eve, but that didn't stop observer Richard Kowalski from scanning the sky for near-Earth objects (NEOs).
He hadn't been using the 60-inch telescope on Arizona's Mount Lemmon for long when he noticed a 19th-magnitude blip skimming through northern Orion in a seven-image series begun at 5:16 p.m. (1:16 Universal Time on January 1st). After confirming that it was a new find, Kowalski dutifully submitted positions and times to the IAU's Minor Planet Center. Then he went back to the night's observing run.
He hadn't been using the 60-inch telescope on Arizona's Mount Lemmon for long when he noticed a 19th-magnitude blip skimming through northern Orion in a seven-image series begun at 5:16 p.m. (1:16 Universal Time on January 1st). After confirming that it was a new find, Kowalski dutifully submitted positions and times to the IAU's Minor Planet Center. Then he went back to the night's observing run.
....
As announced by the MPC earlier today, it's "virtually certain" that 2014 AA hit Earth. According to calculations by dynamicist Stephen Chesley (Jet Propulsion Laboratory), the impact occurred over the Atlantic Ocean somewhere between Central America to East Africa. Chesley's "best-fit" collision is just off the coast of West Africa at roughly 2:30 Universal Time this morning.
...
More precision has come from an analysis of infrasound data by Peter Brown (University of Western Ontario). Infrasound is extremely low-frequency acoustic energy (20 hertz or less) created, for example, during energetic explosions. A global network of detectors, maintained by the Comprehensive Nuclear-Test-Ban Treaty Organization, can pinpoint the location and energy of any powerful detonation — including airbursts from meteoric blasts.
According to Brown, 2014 AA triggered very weak detections at three infrasound stations. His triangulation from those records, shown in the graphic at right, indicates that the space rock slammed into the atmosphere near 40° west, 12° north. That location, about 1,900 miles (3,000 km) east of Caracas, Venezuela, is far from any landmass.
The overlap of the white curves, from three marginal infrasound detections, shows where the small asteroid 2014 AA likely hit. However, this preliminary plot does not take winds into account, which might shift the true impact point somewhat further east.
Peter Brown
"The energy is very hard to estimate with much accuracy — the signals are all weak and buried in noise," Brown explains. And yet, he adds, we're lucky that the event happened just after local midnight, when winds are calmest. "Had this occurred in
the middle of the day I doubt we would see any signals at all," he says.
Brown's rough guess is that the impact energy was equivalent to the explosive power of 500 to 1,000 tons of TNT — which, though powerful in human terms, implies the object was no bigger than a small car. "It was no Chelyabinsk," he says.
So 2014 AA was too small to reach the ground intact. But it must have created one heck of a fireball! The skies over the Atlantic were relatively clear last night. Alas, a search of ship- and plane-tracking websites turned up no vessels in that area — it seems that no one was positioned to witness 2014 AA's demise.
the middle of the day I doubt we would see any signals at all," he says.
Brown's rough guess is that the impact energy was equivalent to the explosive power of 500 to 1,000 tons of TNT — which, though powerful in human terms, implies the object was no bigger than a small car. "It was no Chelyabinsk," he says.
So 2014 AA was too small to reach the ground intact. But it must have created one heck of a fireball! The skies over the Atlantic were relatively clear last night. Alas, a search of ship- and plane-tracking websites turned up no vessels in that area — it seems that no one was positioned to witness 2014 AA's demise.
------------------------------
Probably better to read the whole article.
Larry
------------------------------
Again, back to Red Mars.
Thanks for looking up with me.
- LRK -
==============================
Web Site: http://lkellogg.vttoth.
BlogSpot: http://
WordPress: http://lrkellogg.
RSS link: http://
Newsletter: https://mailman1.
==============================
BlogSpot: http://
WordPress: http://lrkellogg.
RSS link: http://
Newsletter: https://mailman1.
==============================
...
Plot
Red Mars — Colonization
Red Mars starts in 2026 with the first colonial voyage to Mars aboard the Ares, the largest interplanetary spacecraft ever built (interestingly, from clustered space shuttle external fuel tanks which, instead of incinerating in the atmosphere, have been boosted into orbit until enough had been amassed to build a ship and also used as landing craft) and home to a crew who are to be the first hundred Martian colonists. The mission is a joint Russian-American undertaking, and seventy of the First Hundred are drawn from these countries (except, for example, Michel Duval, a French psychologist assigned to observe their behavior). The book details the trip out, construction of the first settlement on Mars (eventually called Underhill) by Nadia Chernyshevski, as well as establishing colonies on Mars' hollowed out asteroid-moon Phobos, the ever-changing relationships between the colonists, debates among the colonists regarding both the terraforming of the planet and its future relationship to Earth. The two extreme views on terraforming are personified by Saxifrage "Sax" Russell, who believes their very presence on the planet means some level of terraforming has already begun and that it is humanity's obligation to spread life as it is the most scarce thing in the known universe, and Ann Clayborne, who stakes out the position that humankind does not have the right to change entire planets at their will.
...
==============================
Kim Stanley Robinson (born March 23, 1952) is an American science fiction writer, best known for his award-winning Mars trilogy. Robinson's work has been labeled by reviewers as literary science fiction.[1]
...
The Mars trilogy
This trilogy is Robinson's best-known work. It is an extended work of science fiction that deals with the first settlement of the planet Mars by a group of scientists and engineers. Its three volumes are Red Mars, Green Mars, and Blue Mars, the titles of which mark the changes that the planet undergoes over the course of the saga. The tale begins with the first colonists leaving Earth for Mars in 2027 and covers the next 200 years of future history. By the conclusion of the story, Mars is heavily populated and terraformed, with a flourishing and complex political and social dimension.
Many threads of different characters' lives are woven together in the Mars Trilogy. Science, sociology, and politics are all covered in great detail, evolving over the course of the narrative. Robinson's fascination with science and technology is clear, although he balances this with a strong streak of humanity. Robinson's personal interests, including ecological sustainability, sexual dimorphism, and the scientific method, come through strongly.
...
==============================
WHAT THE MIND CAN CONCEIVE, AND BELIEVE, IT WILL ACHIEVE - LRK -
==============================
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.