A new asteroid, identified by NASA, could potentially hit the earth on February 5, 2040, even though it is much smaller than the one - nine miles across - which wiped out the dinosaurs 65 million years ago. The UN Action Team on near-Earth objects, which has taken note of the 460-ft asteroid, placed the odds of its hitting the earth at one-in-625, though that could change nearer the time. Scientists have not yet been able to work out much more about it than its size as they have only been able to observe it for half its orbit. But between 2013 and 2016 they will be able to monitor from the ground and will make a moredetailed assessment. In 2023 the rock will make a 'keyhole pass' of Earth, which is an area it passes through on the orbit before it would hit Earth. This will be within a mere 0.02 astronomical units of our planet, or 1.86 million miles, according to NASA's Jet Propulsion Lab. NASA's infrared sky-scans track space objects such as asteroids. A recent scan with the NeoWISE instruments found that there were 19,000 'mid-sized' asteroids within 120 million miles of Earth, the Daily Mail reports. According to NASA, among the ways of deflecting it are putting a probe onto the rock and using the extra gravity the craft generates to steer the asteroid away over millions of light years. Another option would be sending a probe into it so that the impact has the same effect. Nuclear weapons have also been discussed, but this would create a shower of rocks instead of just one. Mid-sized refers to asteroids in a size range between 330 and 3,300 feet wide, which could destroy a city-sized area were they to hit Earth. Source: Ananta-Tec
New asteroid could hit earth in 2040: NASA
A new asteroid, identified by NASA, could potentially hit the earth on February 5, 2040, even though it is much smaller than the one - nine miles across - which wiped out the dinosaurs 65 million years ago. The UN Action Team on near-Earth objects, which has taken note of the 460-ft asteroid, placed the odds of its hitting the earth at one-in-625, though that could change nearer the time. Scientists have not yet been able to work out much more about it than its size as they have only been able to observe it for half its orbit. But between 2013 and 2016 they will be able to monitor from the ground and will make a moredetailed assessment. In 2023 the rock will make a 'keyhole pass' of Earth, which is an area it passes through on the orbit before it would hit Earth. This will be within a mere 0.02 astronomical units of our planet, or 1.86 million miles, according to NASA's Jet Propulsion Lab. NASA's infrared sky-scans track space objects such as asteroids. A recent scan with the NeoWISE instruments found that there were 19,000 'mid-sized' asteroids within 120 million miles of Earth, the Daily Mail reports. According to NASA, among the ways of deflecting it are putting a probe onto the rock and using the extra gravity the craft generates to steer the asteroid away over millions of light years. Another option would be sending a probe into it so that the impact has the same effect. Nuclear weapons have also been discussed, but this would create a shower of rocks instead of just one. Mid-sized refers to asteroids in a size range between 330 and 3,300 feet wide, which could destroy a city-sized area were they to hit Earth. Source: Ananta-Tec
Comets & Neo: Follow-up on 168P/Hergenrother bright phase
(click on the image for a bigger version)
According to reports issued by a number of observers to several astro-forums, comet 168P/Hergenrother is currently experiencing a bright phase: over the course of several nights, it increased in brightness by several magnitudes, reaching a total visual magnitude of approximately 8. We performed some follow-up on it remotely, on 2012 Sept. 26 and Oct. 3, through the 2.0-m f/10.0 Ritchey-Chretien + CCD + Bessel R filter of the Faulkes Telescope South, at Siding Spring Inspecting our stacked images obtained on Sept. 26, the comet shows an obvious central condensation, measuring nearly 3" across; the total coma was traced to a diameter of about 1.7'. On Oct. 3, the central condensation grew to 8" and the total coma diameter was nearly 3'. It's interesting to notice how, apart the growing of the central condensation size, also its appearance changed, appearing pretty sharp on Sept. 26, and a bit "fluffy" on Oct. 3. Subtracting the two images (after normalization of the stackings) of Sept. 26 from Oct. 3, the evolution of the central condensation became obvious. To some extent, the difference might be due to a slight change in the perspective angles (e.g. its phase angle passed from 10 to 13 deg), however we consider that a part of what we see in the panel, is a genuine evolution of the central condensation due to its active phase (click
on the image below for a bigger version). The photometric data supports the observed evolution: our afrho data on Sept. 26 shows a peak of about 670 +/- 100 cm at 2230 km from the photocenter, while on Oct. 3 we measured an afrho of 1210 +/- 150 cm peaking at a radius of about 3000 km from the photocenter. This seems to indicate a two-fold increase of the afrho activity within the central condensation in a matter of a week, as well the apparent recession of the activity peak from the central condensation. A change in the photometric profile of the coma is also obvious, from the comparison of the two panels, with the Oct. 3 
graph significantly wider and less steep, compared to that of Sept. 23. So our follow-up confirms and adds scientific data to the previous reports: currently comet 168P/Hergenrother is alive and rather active. Giovanni Sostero, Nick Howes, Alison Trip and Ernesto Guido. Source: Eemanzacco Observatory
'Nuke won't save us from asteroid'
WHEN Bruce Willis used a nuclear bomb to save Earth from a giant asteroid in the movie Armageddon, the scenario had little science and a lot of fiction, physicists have said. Willis' nuke would have had as much impact on the rock as a cheap firecracker and was used so late that the planet would have been doomed anyway, they said. "Our current level of technology is simply nowhere near sufficient to protect Earth from such an asteroid by this specific means of asteroid defence," according to a paper published by students at the University of Leicester, central England. In the 1998 close-call blockbuster, Willis plays a deep-core driller sent by NASA to stop a Texas-sized rogue rock on collision course with Earth. He lands on the asteroid and embeds a nuclear device that once detonated splits the projectile into two pieces that shave past on either side of Earth. The research team said blowing up an asteroid of that size, about 1000 kilometres in diameter, would require a bomb a billion times stronger than the biggest one ever detonated on Earth - the Soviets' "Big Ivan" that was exploded at a test site in 1961. In any case, the asteroid would have to be detected much, much sooner than in the film, the team writes in the university's Journal of Special Physics Topics. The 18-day headstart in Armageddon "would leave no time for Bruce to travel to the asteroid and drill into its centre, let alone share any meaningful moments with Ben Affleck or Liv Tyler along the way", says the study, entitled "Could Bruce Willis Save the World?" Tyler plays Willis' onscreen daughter and Affleck her love interest. In reality, the asteroid would have to be detected and blown up 13 billion kilometres from Earth - thus on the outer reaches of the Solar System - to give the two halves enough time to alter their course and miss the planet. It is not all bad news, though. If the end of the world is pencilled for December 21, 2012 - the date said to be indicated by the Mayan calendar - that does give us some months to do something about it. "One possible alternative method would be moving the asteroid via propulsion methods attached to it," said 22-year-old co-author Ben Hall. "What is certain is that most methods would require very early detection of such an asteroid and very careful planning in deriving a solution."Source: Sam Daily TimesNew Comet: P/2012 O2 (MCNAUGHT)
Cbet nr. 3189, issued on 2012, July 23, announces the discovery of a new comet (discovery magnitude 18.3) by R. H. McNaught on CCD images obtained with the 0.5-m Uppsala Schmidt telescope at Siding Spring on July 20.7. The new comet has been designated P/2012 O2 (MCNAUGHT). We performed some follow-up measurements of this object, while it was still on the neocp. Stacking of 13 R-filtered exposures, 10-sec each, obtained remotely, from the Haleakala-Faulkes Telescope Northon 2012, July 23.5, through a 2.0-m f/10.0 Ritchey-Chretien + CCD, shows that this object appears "soft" compared to the nearby field stars of similar brightness (stellar FWHM of 1.0") and elongated toward PA 260. Our confirmation
image in false color to enhance the coma and its elongation. M.P.E.C. 2012-O27 (including previously unpublished prediscovery Mount Lemmon observations acquired by A. Gibbs on May 20) assigns the following preliminary elliptical orbital elements to comet P/2012 O2: T 2012 June 25.09; e= 0.54; Peri. = 183.05; q = 1.66 AU; Incl.= 24.53. by Ernesto Guido, Giovanni Sostero & Nick Howes. Source: Remanzacco Observatory
Asteroid crashes delivered water on Earth
Meteorites
Asteroids from the inner solar system may be the source of the majority of Earth's water, a new study has claimed, contradicting the belief that most of our planet's water originated in the outer solar system. The prevailing theories suggest that water was delivered on Earth from outer solar system by comets that coalesced beyond Jupiter's orbit, then migrated inward. "Our results provide important new constraints for the origin of volatiles in the inner solar system, including the Earth," said lead researcher Conel Alexander of the Carnegie Institution of Washington. "And they have important implications for the current models of the formation and orbital evolution of the planets and smaller objects in our solar system," Alexander was quoted as saying by SPACE.com. For their study, published in the journal Science, the researchers analysed samples from 86 carbonaceous chondrites. The primitive meteorites are thought to be key sources of the early Earth's volatile elements like hydrogen and nitrogen. The team measured the abundance of different hydrogen, nitrogen and carbon isotopes in the chondrite samples. Isotopes are versions of an element that have different numbers of neutrons in their atomic nuclei. For example, the isotope deuterium -- also known as heavy hydrogen -- contains one neutron, while normal hydrogen has none. The amount of deuterium in celestial bodies water ice sheds light on where the objects formed in the solar system's early days. In general, bodies that took shape farther from the sun have relatively higher concentrations of deuterium, the researchers said. The 86 chondrite samples' deuterium content -- which the team gleaned from clays, the remnants of water ice -- suggest the meteorites' parent bodies formed relatively close to Sun, perhaps in the main asteroid belt between Mars and Jupiter. Comets, by contrast, have much higher deuterium ratios. As a result, scientists think most of them were born in the solar system's frigid outer reaches. The isotopic composition of the bulk Earth appears to be more consistent with chondrites than with comets, they said. There are many different types of chondrites and no single group is a perfect match. So our planet probably accreted its water and other volatiles from a variety of chondrite parent asteroids, they added. Source: Hindustan Times
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