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Sat, 25 Feb 2017
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Fireballs


Fireball 4

Meteor fireball sighted over South Island, New Zealand

© Photo Twitter (@iangriffin)
Clear skies around the country allowed for sightings of what may have been a meteor (not pictured) last night.
Reports of a bright light shooting across the skies last night have come in from around the country, including Dunedin.

ODT Online submitter Peter Simkins relates looking out of his window in Broad Bay towards Port Chalmers and seeing a ''yellow streak of light plummeting to earth''.

Other sightings have come in from in Blenheim, Porirua, Lake Ferry, Martinborough and New Plymouth.

Some people posted on social media about seeing the sky light up, while others described the light as being green in colour. Fairfax is this morning reporting that it may have been may be a Russian cargo rocket re-entering the earth's atmosphere.

One woman posted on Facebook that she saw the light in Lower Hutt.

"Yup saw it clearly in Lower Hutt. It was huge and the tail colorful."

The Herald was unable to contact an expert to comment on the sighting tonight, but a person at the University of Canterbury's Mt John Observatory said descriptions provided indicated people had seen a meteor.

According to Nasa, small chunks of rock and debris in space are called meteoroids.

They become meteors, or shooting stars, when they fall through a planet's atmosphere; leaving a bright trail as they are heated to incandescence by the friction of the atmosphere. Pieces that survive the journey and hit the ground are called meteorites.

Fireball 4

Asteroid 2017 DG16 to fly by Earth at 0.34 LD - 5th known NEA to flyby Earth within 1 lunar distance since January 8, 2017

© Minor Planet Center
The green line indicates the object's apparent motion relative to the Earth, and the bright green marks are the object's location at approximately one hour intervals. The Moon's orbit is grey. The blue arrow points in the direction of Earth's motion and the yellow arrow points toward the Sun.
A newly discovered asteroid named 2017 DG16 will flyby Earth at a very close distance of 0.34 LD (130 560 km / 81 126 miles) from the surface of our planet at 21:08 UTC on February 23, 2017. This is the fifth known near-Earth asteroid to flyby Earth within 1 lunar distance since January 8, 2017.

2017 DG16 was first observed by Mt. Lemmon Survey on February 21. The estimated size of this asteroid is between 2 and 8 m (6.5 - 26.2 feet). It will flyby Earth at a speed (relative to the Earth) of 6.91 km/s.

This object belongs to the Apollo group of asteroids, Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Earth (> 1 AU) but perihelion distances less than the Earth's aphelion distance (q < 1.017 AU).

Fireball

Three meteor fireballs reported over Cheltenham, UK in two days

© Via Facebook/Stef Kotwica
Did you see two fireballs in the sky above Cheltenham on Sunday evening?

We have been contacted by someone who said they saw the phenomenon as they drove along Princess Elizabeth Way.

He asked us via twitter: "Seen two fireballs in the sky when heading down Princess Elizabeth Way. Heard anything?" He added that he was driving with his son and noticed two bright lights which dimmed and left smoke trails. I really can't believe me and my son would have been the only ones to see them, they were bright enough," he said.


Stop

East London gallery under fire for hosting 'neo-Nazi' art & 'Islamophobic' speakers

© Kacper Pempel / Reuters
A London art gallery has been criticized for exhibiting neo-Nazi artwork, hosting openly Islamophobic speakers and "promoting fascism."

LD50, in Dalston, east London, is facing calls to shut down over an exhibition and a series of talks hosted by the far right or so-called 'alt-right' movement, which is known for its vehement anti-liberal stance, often favoring white supremacist views.

Last summer, the gallery, run by Lucia Diego, held a 'neoreaction conference' featuring speakers including Peter Brimelow, Brett Stevens and Iben Thranholm. 'Neoreaction' is a 'philosophy' which rejects democracy, is anti-egalitarian and embraces autocratic rule.

Fireball 3

Bright meteor fireball seen over northern U.S and Canada

A very bright fireball was seen in the northern US and Canada around 04:53 UTC on February 18, 2017. The event was captured in 3 NASA all-sky cameras and cameras belonging to the Southern Ontario Meteor Network.

Analysis of the video data shows that the meteor was first detectable at an altitude of 83 km (52 miles) above US Highway 219, southeast of the Pennsylvania town of DuBois. It then moved northeast some 42 km (26 miles) through the atmosphere at almost exactly 64 400 km/h (40 000 mph), ablating 42 km above the countryside just north of Winslow Hill, NASA's Meteoroid Environment Office (MEO) said.

The camera data shows very little deceleration of the meteor, which gives it a poor chance of producing meteorites, MEO said and added that more analysis is required to rule this out. "The object had the brightness of a quarter Moon, which means we are dealing with an asteroid fragment weighing about 9 kg (20 pounds), with a diameter of roughly 18 cm (7 inches)."


Fireball 2

Bright meteor fireball lights up sky in Southern Alabama

© NASA
The reports of sound indicate that it penetrated fairly low into the atmosphere before fragmenting, perhaps as low as 14 miles in altitude.
Local 15 has confirmed with NASA that a bright meteor was seen just after 9 p.m. Saturday.

Saturday night reports began circulating on social media about a large fireball in the sky and a loud boom. Residents in Southern Alabama reported that they heard a loud boom that shook their homes. NASA says that the fireball first appeared to the Northeast of Mobile and moved west at about 56,000 miles per hour.

The average brightness is that of the Full Moon, leading experts to believe that it was probably about a foot or two in diameter. Using eyewitness reports and a software tool to derive a ground track NASA was able to conclude that the best reports indicate the meteor broke apart above U.S. 43, just North of Mobile.

The reports of sound indicate that it penetrated fairly low into the atmosphere before fragmenting, perhaps as low as 14 miles in altitude.

Comment: This meteor was also reported in western Florida.


Fireball

Rare asteroid discovered along the orbit of Uranus

© NASA/Erich Karkoschka (Univ. Arizona)
Now with added Trojans.
A rare Trojan asteroid of Uranus has been found, following the same orbit as the planet. Its existence implies there could be many more of these companion asteroids, and that they are more common than we thought.

A Trojan asteroid orbits the sun 60 degrees ahead of or behind a planet. Jupiter and Neptune have numerous Trojans, many of which have been in place for billions of years. These primordial rocks hold information about the solar system's birth, and NASA has just announced plans to visit several of them in the 2020s and 2030s.

But Saturn and Uranus live in a rougher neighbourhood: the giant planets on either side of them yank Trojans away through their gravitational pull. So Saturn has no known Trojan, and Uranus had only one.

In July, though, astronomers reported a new asteroid, named 2014 YX49, that shares Uranus's orbital period of 84 years. Now computer simulations of the solar system by brothers Carlos and Raul de la Fuente Marcos at the Complutense University of Madrid, Spain, indicate the asteroid is a Uranus Trojan. The simulations show that the asteroid has maintained its position ahead of Uranus for thousands of years.

"It is bigger, probably twice as big as the first one," says Carlos. The new asteroid is brighter than the first, but its exact size depends on how much light its surface reflects. If it reflects half the sunlight striking it, it's 40 kilometres across; if it reflects 5 per cent, its diameter is 120 kilometres.

Fireball

Valentine's Day meteor fireball spotted over Eastern US

© Chris Wolf/AMS
AMS Event#614-2017 – screeenshot of a video shared by Chris Wolf on the AMS Website.
53 reports from Pennsylvania, Connecticut, New Jersey, New York and Maryland

The AMS has received 63 reports so far about of a fireball event over seen over Pennsylvania on Tuesday, February 14th 2017 around 08:32pm EST (Feb 15th - 01:39 UT.). The fireball was seen primarily from Pennsylvania but witnesses from Connecticut, New Jersey, New York, and Maryland also reported the event. Some witnesses described the meteor as orange, yellow and white. After a fairly extensive investigation, we came to the conclusion that it wasn't Cupidon but a bright meteor.

First Estimated Trajectory

The map below shows the witnesses location with the first estimated trajectory. The preliminary estimated trajectory plotted from the witness reports shows the meteor was traveling from the West to the East and ended its flight somewhere over Scranton, PA.

Meteor

Mystery object (possibly a meteorite) lands in UK garden after loud thump in middle of night

© Bury Times
This mysterious rock like object is causing quite a stir in Lowercroft.

Now the couple in whose garden it was found are hoping someone may be able to shed some light on what it is — and where it came from.

Pauline and Norman Pollard were baffled to discover the striking black and yellow material in their garden, just days after hearing a loud noise.

Initially the couple thought it may be a meteorite - and don't know whether the noise is related to the find.

Mr Pollard, who lives in Lowercroft Road, aged 74, said: "We found it in the garden after we had heard a loud bang or thump in the middle of the night, it was like a car door banging."

Info

Cause of noises made by meteors found

© Spalding et. al./Scientific Reports
Bright, flaring meteors are sometimes accompanied by faint noises. What's strange about these popping, sizzling, rustling, and hissing sounds are that they reportedly occur almost instantly to earthly onlookers. This makes little sense, as meteors are as far as sixty miles away from viewers on the ground, so any sound they make should take several minutes be heard. What's going on? Do meteors somehow defy the laws of physics?

Researcher Richard Spalding and several of his colleagues at Sandia National Laboratories recently set out to study this strange phenomenon, and in a study just published to the journal Scientific Reports, they announce that the sounds are likely created through light.

Meteor fireballs sometimes pulse with light many times brighter than the full Moon, and these blasts can briefly heat the surfaces of objects many miles away. Such sudden temperature changes can actually create sound.

"We suggest that each pulse of light can heat the surfaces of natural dielectric transducers," Spalding and his colleagues write. "The surfaces rapidly warm and conduct heat into the nearby air, generating pressure waves. A succession of light-pulse-produced pressure waves can then manifest as sound to a nearby observer."