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Mon, 20 Aug 2018
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Comets


Comet 2

Comet: C/2018 N2 (ASASSN)

MPEC 2018-O01, issued on 2018, July 16, announces the discovery of a comet (magnitude ~16.1) in the course of the "All-Sky Automated Survey for Supernovae" (ASASSN) program, in images taken 2018 July 7-11 with the 14-cm "Cassius" survey telescope at Cerro Tololo. The new comet has been designated C/2018 N2 (ASASSN).

I performed follow-up measurements of this object, while it was still on the PCCP webpage. Stacking of 10 unfiltered exposures, 60 seconds each, obtained remotely on 2018, July 15.7 from Q62 (iTelescope network) through a 0.43-m f/6.8 astrograph + CCD, shows that this object is a comet with a diffuse coma about 15 arcsec in diameter.

My confirmation image (click on it for a bigger version)
Comnet C/2018 NZ
© Remanzacco Blogspot

Info

NASA may have recovered meteorite from the ocean

Underwater Meteorite
© Pixabay Composite
Just two days into their search for a giant meteorite that crashed off the coast of Washington State, Dr. Marc Fries and the crew of the Nautilus have accomplished their mission: they believe they have successfully recovered pieces of the two-ton meteorite that created a huge fireball the size of a minivan as it streaked into the Pacific. Further analysis is in the works but - if these fragments are genuine - they'll be the first-ever pieces of a meteorite recovered from the ocean.

Based on Fries' calculations of the meteorite's trajectory, the Nautilus narrowed its search to a 0.4 square-mile patch of the ocean. The area was first searched with sonar, then with two ROVs (remotely operated vehicles) named Argus and Hercules. The team then used "a suction hose sampler, magnetic plate, and sediment scoop" to pick up the most promising pieces of rock.

The two fragments found so far are thought to be the outer shell of the meteorite (called the fusion crust) which the Nautilus Live blog describes as "meteorite exterior that melted and flowed like glaze on pottery as it entered the atmosphere."

Comet 2

'Oumuamua reclassified from 'asteroid' to 'comet' (because they're essentially the same thing)

Researchers have found that 'Oumuamua - the first confirmed object to enter the solar system from interstellar space - was a comet, releasing just enough gas to subtly change its course.
'Oumuamua
© ESA / Hubble / NASA / ESO / M. Kornmesser
An artist's impression shows 'Oumuamua as a comet.
In October 2017 the robotic telescope Pan-STARRS in Hawai'i detected an unusual object entering the solar system from interstellar space. In the days after the discovery, every available telescope, including Hubble, was aimed at the interloper to collect as much information as possible before it left our system. Since then, astronomers worldwide have been reviewing the observations, trying to squeeze as much knowledge as possible about the unexpected visitor.

Named 'Oumuamua ("first scout" or "first visitor" in Hawaiian), this envoy from the stars appeared to have the form of an elongated cigar - or a flattened pancake, depending whom you ask - 800 meters (0.5 mile) long and 10 times thinner. It came tumbling into the solar system from above the plane of the planets, only to have its path changed by the by the Sun's gravitational pull before leaving out system again, never to return.

Comment: How these numpties still don't get it is beyond us.

Asteroids and comets ARE THE SAME THINGS. The former just 'become' the latter when they discharge electrically due to relative electric potential difference as they pass through space.


Meteor

US National Science and Technology Council calls for improved asteroid detection, tracking and deflection

NASA asteroid tracking deflection

On Wednesday, June 20, 2018, the U.S.'s National Science and Technology Council released a report calling for improved asteroid detection, tracking and deflection. NASA is taking part in the effort, along with federal emergency and White House officials.
The U.S. government is stepping up efforts to protect the planet from incoming asteroids that could wipe out entire regions or even continents.

The National Science and Technology Council released a report Wednesday calling for improved asteroid detection, tracking and deflection. NASA is participating, along with federal emergency, military, White House and other officials.

For now, scientists know of no asteroids or comets heading our way. But one could sneak up on us, and that's why the government wants a better plan.


Comment: And they are sneaking up on us with increasing frequency.


NASA's planetary defense officer, Lindley Johnson, said scientists have found 95 percent of all these near-Earth objects measuring one kilometer (two-thirds of a mile) or bigger. But the hunt is still on for the remaining 5 percent and smaller rocks that could still inflict big damage.

Comment: Looks like someone has been paying attention to the alarming number of space rocks in our skies recently:


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