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Tue, 22 May 2018
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Comets


Comet

Asteroid 3 times larger than Chelyabinsk making close approach... TODAY!

asteroid 2010 WC9
© JPL/NASA
Asteroid 2010 WC9
Last night in Australia, near-Earth asteroid 2010 WC9 glided silently across the starry sky of Brisbane while the city's residents slept. Well... not every resident slept. Amateur astronomer
asteroid 2010 WC9
© Dennis Simmons
Asteroid 2010 WC9
Dennis Simmons was wide awake and recorded the flyby:

"The asteroid moved rapidly through the constellation Hercules shining about as brightly as a 15th magnitude star," says Simmons. "The 'wobbly' appearance of the trail is as a result of slight periodic errors in the telescope mount's gear train. This is not caused by the asteroid tumbling!"

Tonight, the view will improve - a lot. On May 15th, 2010 WC9 will fly through the Earth-Moon system, splitting the distance between our planet and the Moon. At closest approach (203,000 km), the asteroid will glow like an 11th magnitude star (~40 times brighter than shown above) as it races through the southern constellation Pavo (the Peacock).

2010 WC9 is known as the "lost asteroid" because astronomers lost track of it soon after it was discovered in November 2010. The asteroid receded from Earth and didn't return for nearly 8 years... until now.

Galaxy

Rogue star Gilese 710 hurtling towards our solar system will arrive sooner than we thought

Gliese 623 A

Gliese 710 may be as dim as a red dwarf star, like Gliese 623 A (M2.5V) and B (M5.8Ve) at lower right.
According to new calculations, we may have a little less time to prepare for a star on course to kiss the edges of our Solar System.

Yep. Dwarf star Gliese 710, which we've known about for some time, could now arrive in 1.29 million years, instead of the previously calculated 1.36 million years.

Gliese 710 is what is classified as a rogue star - one that has gone roaming across the galaxy, free of the gravitational chains that normally hold stars in position.

At a speed of 51,499 kilometres per hour (32,000 miles per hour), it's not quite fast enough to be considered a runaway star, but it's still travelling at a hefty clip.

Comment: Whilst the flyby is apparently over a million years away, we should bear in mind that Gilese 710 is a body we know about and the predictions are based on our current models, because it is often the case that we are taken by surprise:


Fireball

Incoming close calls! NASA says 5 'close' asteroid flybys will take place today

Asteroids
© NASA
The five asteroids will fly past the Earth roughly ten times farther away than the Moon but at tremendous speed.
The Earth will experience a number of (relatively) close calls in one day, as NASA reports that an alarming total of five asteroids will hurtle towards - but happily not quite at - our planet.

The Center for Near Earth Object Studies at NASA's Jet Propulsion Laboratory in California publishes a comprehensive list of space rocks that are worth keeping an eye on, just to prepare yourself for any potential armageddons or extinction-level collisions. These rocks can range in size from a few meters in length to asteroids more akin to skyscrapers.

The series of space rock flybys begins at 10:29 UTC Sunday as asteroid 2013 US3, travelling at a respectable 7.69 km/s (27,646 kph) with a diameter of between 160-360 meters whizzes past us. For comparison, the Eiffel Tower measures 324 meters from ground to tip.

Fireball 4

Threat assessment: NASA's asteroid hunter charted scariest, Earth-bound objects

Outer space
© REUTERS/NASA/JPL-Caltech/Handout / Reuters
File NASA image shows an artist's concept of an asteroid breaking up as it travels in space.
Hundreds of cosmic objects swarming unnervingly close to Earth come to life in an intimidating new NASA visualization, based on the latest data from its asteroid-hunting mission.

NEOWISE has charted almost 30,000 objects since it resumed its work in 2013, including 788 near-Earth objects and 136 comets. Ten of the objects discovered by NEOWISE in the past year alone have been classified as potentially hazardous asteroids (PHAs).

NASA's latest animation is based on detections made by the telescope over its last four years of surveying the solar system. The green dots represent near-Earth asteroids while the yellow dots stand for comets.

Info

Scholz's star disturbed prehistory solar system comets

Scholz's Star
© José A. Peñas/SINC
At a time when modern humans were beginning to leave Africa and the Neanderthals were living on our planet, Scholz's star approached less than a light-year.
About 70,000 years ago, during human occupation of the planet, a small, reddish star approached our solar system and gravitationally disturbed comets and asteroids. Astronomers from the Complutense University of Madrid and the University of Cambridge have verified that the movement of some of these objects is still marked by that stellar encounter.

At a time when modern humans were beginning to leave Africa and the Neanderthals still thrived, Scholz's star-named after the German astronomer who discovered it-approached less than a light-year from the sun. Today, it is almost 20 light-years away, but 70,000 years ago, it entered the Oort cloud, a reservoir of trans-Neptunian objects located at the confines of the solar system.

This discovery was made public in 2015 by a team of astronomers led by Professor Eric Mamajek of the University of Rochester (USA). The details of that stellar flyby, the closest documented so far, were presented in The Astrophysical Journal Letters.

Now, two astronomers from the Complutense University of Madrid, the brothers Carlos and Raúl de la Fuente Marcos, together with the researcher Sverre J. Aarseth of the University of Cambridge (United Kingdom), have analyzed for the first time nearly 340 solar system objects with hyperbolic orbits (very open V-shaped, rather than elliptical) They have concluded that the trajectories of some of these were influenced by the passage of Scholz's star.

Comet 2

New Comet: C/2018 E1 (ATLAS)

CBET nr. 4494, issued on 2018, March 16, announces the discovery of an apparently asteroidal object (magnitude ~17) in the course of the "Asteroid Terrestrial-impact Last Alert System" (ATLAS) search program on CCD images obtained with a 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii. Posted on the Minor Planet Center's PCCP webpage, it has been reported as showing cometary activity by CCD astrometrists elsewhere. The new comet has been designated C/2018 E1 (ATLAS).

I performed follow-up measurements of this object, while it was still on the PCCP webpage. Stacking of 5 unfiltered exposures, 60 seconds each, obtained remotely on 2018, March 12.4 from Q62 (iTelescope network) through a 0.70-m f/6.6 reflector + CCD, shows that this object is a comet with a diffuse coma about 5 arcsec in diameter. The FWHM of this object was measured about 20% wider than that of nearby field stars of similar brightness.

My confirmation image (click on it for a bigger version)
Comet C/2018 E1 Atlas
© Remanzacco Blogspot
"Pre-discovery" Panstarrs observations (2015 & 2016) were identified by R. Weryk. M.P.E.C. 2018-F10 assigns the following elliptical orbital elements to comet C/2018 E1: T 2018 Apr. 17.3; e= 0.95; Peri. = 299.47; q = 2.70; Incl.= 72.48

Fireball 2

Spectacular meteor fireball spotted over New Zealand

Meteor
© iStock
Dairy farmer Brent White says the meteor he saw on early Saturday morning was "spectacular".
A Manawatu farmer has discovered the importance of carrying a cellphone after he saw a spectacular fiery meteor display but couldn't get a photo.

Dairy farmer Brent White saw the "spectacular" meteorite fly right in front of him at around 4:30am on Saturday when he was bringing cows into the dairy shed.

"I'm hoping someone else saw it... I didn't have my phone on me unfortunately."

Mr White says he ran back to the shed to see if the milk tankers at the shed had seen the meteor, but they were busy working and missed it.

"It was spectacular. It was surreal. It was such a clear morning... and all of a sudden at about 4:35, out of my left eye I saw a bright light.

"It was definitely a meteor; it was a ball-like formation with a vortex."

Fireball 2

Fast moving meteor fireball captured on dashcam over Russian city

Meteor
© Sputnik News
A driver in the Russian city of Yekaterinburg in the Ural Mountains has managed to capture the fall of what researchers claimed was an extremely fast meteor, according to local media reports.

Vladilen Sanakoyev of the Ural Federal University's educational observatory in Yekaterinburg has given his thoughts on the video with what looked like a massive falling ball of fire, local media outlets have reported.

According to him, a blue flash in the footage indicates that the celestial body was flying at a high speed when a car's dashboard camera captured the moment of the alleged meteor falling from the skies in the Russian Urals city.


Fireball

Bus-sized asteroid to pass Earth on 2nd March

Asteroid
© NASA/JPL-Caltech
This coming Friday, March 2, an near-Earth asteroid will be sweeping within 70,000 miles (113,000 kilometers) of our planet's surface.

While there's no danger of any collision, asteroid 2018 DV1 will be coming closer to Earth than the Moon, which is nearly always enough to grab the attention of asteroid-hunters. And on top of that, 2018 DV1 is about 23 feet (7 meters) wide, which NASA's official Asteroid Watch declared was about the size of a bus.

And it should make for an impressive sight if you have the necessary tools to see it. Assuming that you don't have access to powerful telescopes, you can watch a live stream of the asteroid passing through the night sky from the Virtual Telescope Project and Tenegra Observatories in Arizona, who will be showing the video on their website.


Fireball

The Big Burn - Global fire 13k years ago

YDB Event
© UC Santa Barbara
Black dots represent locations of 129 lake cores exhibiting charcoal records and purple dots represent marine sites with charcoal and/or soot spanning the Younger Dryas onset.
Some 13,000 years ago, a cataclysmic event occurred on Earth that was likely responsible for the collapse of the Clovis people and the extinction of megafauna such as mammoths and mastodons.

That juncture in the planet's geologic history - marked by a distinct layer called the Younger Dryas Boundary - features many anomalies that support the theory of a cometary cloud impacting Earth. The collision triggered a massive biomass burning event, and the resulting soot, ash and dust in the global atmosphere blocked out the sun, which prevented photosynthesis - a phenomenon called impact winter.

For more than a decade, UC Santa Barbara professor emeritus James Kennett has studied elements found at the Younger Dryas Boundary (YDB). He has collaborated with scientists around the globe, providing evidence at the YDB for a platinum peak as well as for spherules, melt glass, nanodiamonds and other exotic materials that can be explained only by cosmic impact.

Kennett and his colleagues have now published new research in the Journal of Geology. In two papers, they analyze existing published scientific data from ice, glacier, lake, marine and terrestrial sediment cores, finding evidence for an extensive biomass burning episode at the YDB layer representing one of the most extreme events - if not the most extreme - ever experienced by our own species, anatomically modern humans. Recent extreme climate and burn events like those in California pale by comparison, Kennett said.

Comment: 12,800 years ago: Cosmic impact produced global fires larger than dinosaur killer event - Research