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Mon, 20 Feb 2017
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Comets


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.
Mobile — 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.

We will continue to update this story as we gather more information. If you have pictures or video send them to Burst.com/Local15

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.

Telescope

Look up tonight! Stunning 'Snow moon' eclipse and a mysterious green comet are set to appear in the night sky

© NASA Jet Propulsion Lab/California Institute of Technology
Along with the lunar eclipse, Comet 45P will make its closest approach to Earth this weekend. The comet makes its way back to the inner solar system roughly every 5 years, and has a bright bluish-green 'head'
It's almost time to get your binoculars at the ready, as this evening looks set to offer some stunning astronomical events to viewers around the world. A lunar eclipse is forecast to appear on a snow moon - a full moon that occurs in February - casting a shadow across the lunar surface.

And just a few hours later, Comet 45P - also known as the New Year comet - will make its closest approach to the Earth.

The full event will be live streamed on Slooh, who will be filming the skies from the Canary Islands.

An eclipse of the moon occurs when the sun, Earth and moon line up, with Earth in the middle.

This alignment causes the Earth's shadow to fall on the moon, creating a lunar eclipse.

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."

Comet 2

Comet 45P approaches Earth - Closest approach on Feb. 11th

© Michael Jäger
A small comet named "45P/Honda-Mrkos-Pajdusakova" (45P for short) is approaching Earth. At closest approach on Feb. 11th, the comet will be 7.4 million miles from our planet, visible in binoculars and small telescopes. This is what it looks like (image on the left).

Michael Jäger of Stixendorf, Austria, took the picture on Dec. 31, 2016, just as the comet was swinging around the sun en route to Earth. Since then 45P's icy nucleus has been heated by solar radiation, causing it to spew brightening jets of gas into the comet's green atmosphere. Why green? Because the comet's vaporizing nucleus emits diatomic carbon, C2, a gas which glows green in the near-vacuum of space.

According to the Minor Planet Center, this is the 8th closest pass of any comet in the modern era (since ~1950, when modern technology started being used to study comets). It will only be 31 times farther from Earth than the Moon.

Interestingly, 45P made an even closer approach on its previous orbit (23 lunar distances), so it is also on the list as the 5th closest.

Proximity makes the comet bright despite its small size. Forecasters say 45P could be on the verge of naked eye visibility (6th magnitude) when it emerges into the pre-dawn sky later this week. The best time to look is during the dark hours before sunrise between Feb 9th and 12th. The comet will be racing through the constellation Hercules high in the eastern sky. Sky maps: Feb. 9, 10, 11, 12.

Got a great picture? First, submit it to Spaceweather.com. Next, send it to the Planetary Science Institute, which is collecting amateur images to help professional researchers study Comet 45P. More resources: 3D Orbit, Ephemeris.

Fireball 2

Asteroid attack? Yet another asteroid to give Earth a close shave

© ESA
Space rock block party!
For the fourth time since the start of 2017, a small celestial body will pass closer to Earth than the distance between us and the moon. Recently discovered asteroid 2017 BS32 zips by around midday Thursday.

This latest narrow shave comes just a few days after the closest such flyby in months, prompting observers and some astronomers to wonder if the apparent blitz of tiny planetoids could be more than mere coincidence.

According to astronomer Paul Cox at the Slooh observatory, the apparent bursts of small, close-approaching asteroids were first spotted just before buzzing us initially sparked discussion in 2016.

"One possibility sprang to mind -- that these clusters of smaller asteroids making close approaches to Earth over relatively short periods of time were in fact the fragments from larger asteroids that had broken up," Cox said via email. "However, when we reviewed the orbits of each of the asteroids, we found no correlation between them -- showing clearly they weren't associated in any way."

Cox said the scientists also looked for a connection to seasonal changes or to weather at observatories that might reduce discoveries of nearby asteroids, but there was no conclusive data to be found.

Comet

Anything to worry about with 'death asteroid' WF9?

© shutterstock
By now you've probably heard of 2016 WF9. Everybody is freaking out about this 'death asteroid' and, if the predictions hold up, it really is something to worry about. Except, as you might have guessed, the predictions do not actually hold up.

There's really only one person saying WF9 is the Sweet Meteor of Death some people were rooting for in the 2016 election: Dyomin Damir Zakharovich, a Russian astronomer who claims that the asteroid is actually a piece of Nibiru. What, you might ask, is Nibiru? Why, it's a planet we were told about by Nancy Lieder, a woman who claims to be in telepathic contact with aliens from Zeta Reticuli. This would be a good point to bring up that the "Nibiru cataclysm" was supposed to have happened in 2003.

In rather sharp contrast to the doomsaying, here's what NASA had to say about 2016 WF9:
2016 WF9 will approach Earth's orbit on Feb. 25, 2017. At a distance of nearly 32 million miles (51 million kilometers) from Earth, this pass will not bring it particularly close. The trajectory of 2016 WF9 is well understood, and the object is not a threat to Earth for the foreseeable future.

Comment: An asteroid is about to slip between Earth and the moon — the second near miss in 3 weeks


Fireball

Meteor fireball spotted over Leeds, UK

© Yorkshire Evening Post
The meteor over Allerton Bywater.
Is this a meteor in the skies over Leeds?

Kelly Moss snapped the burning light hovering over Brigshaw High School in Allerton Bywater at around 4.30pm on Wednesday, as dusk was falling.

A meteor, often called a shooting star, is the visible passage of a glowing meteoroid, micrometeoroid, comet or asteroid through Earth's atmosphere, after being heated to incandescence by collisions with air molecules in the upper atmosphere, creating a streak of light via its rapid motion and sometimes also by shedding glowing material in its wake.

Fireball

Mysterious boom rattles San Diego residents

© 7 San Diego
Several people across San Diego County reported hearing a loud, mysterious boom Tuesday afternoon.

An NBC 7 viewer told us, around 3:18 p.m., she heard two loud booms that shook the windows in her home in Santee.

There were multiple posts on social media of people reporting their homes rattled from the boom. The posts were from residents across the county, including Clairemont, Santee, and San Diego.

Some wrote that they suspected the sounds were caused by a sonic boom, but NBC 7 has not confirmed that.

Comment: Fox News San Diego reports two large "bangs" were heard. Residents also reported a car moving back and forth and a "large glowing ball in the western sky".


Fireball 4

Brilliant green meteor fireball photographed over Southern India

© Prasenjeet Yadav
While exploring the sky islands of the Western Ghats in 2015, molecular ecologist turned photographer Prasenjeet Yadav shot a rather rare photograph with a green meteor up in the sky and the twinkling lights of the town below. It earned him a plethora of awards, including National Geographic Nature Photographer of the year, 2016, and also an Honourable Mention in the Landscape Category by National Geographic. The photograph was shot on October 9, 2015, and Yadav was at the Nilgiri's near Ooty when he shot the green meteor. The town he is overlooking is Mettupalayam.

"This is probably the only composed photo of a green meteor. No photographer can plan this shot. This can happen for a fraction of second anywhere in the universe, and the fun part is, I was sleeping when my camera captured it. Everything else was hard work but for those 15 seconds, I was the luckiest photographer on the planet," says Yadav, who was working on a story on sky islands of Western Ghats when he shot this. Along with bird ecologist Dr Robin Vijayan, Yadav was working on a project to understand the role these mountains play in the formation of new species.

Born in Nagpur, Yadav went to Bangalore to pursue research at the National Center for Biological Science. In 2013, he moved to photography and began concentrating on environment and conservation stories. He is reportedly the only Indian to be represented by the National Geographic Creative. Although he has stepped away from the academic realm, Yadav considers himself a non-traditional scientist and often collaborates with researchers, policy makers and conservationists for his projects in the world of nature photography. Currently, he is working on a story on the sky islands of southern India for National Geographic and is documenting the unseen species of amphibians, reptiles, birds and mammals found only in the south Western Ghats.