Comets

New Comet C/2020 S3 (Erasmus)

Ernesto Guido
Remanzacco Blogspot
Mon, 21 Sep 2020 18:12 UTC

CBET 4885 & MPEC 2020-S119, issued on 2020, September 20, announce the discovery of a comet (magnitude ~18.5) by Nicolas Erasmus (South African Astronomical Observatory), in four 30-s CCD images taken in 5" seeing on Sept. 17.6 UT with a 0.5-m f/2 Schmidt reflector at Mauna Loa, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. The new comet has been designated C/2020 S3 (Erasmus).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 151 unfiltered exposures, 30 seconds each, obtained remotely on 2020, September 19.1 from L07 (Osservatorio Salvatore di Giacomo, Agerola) through a 0.5 m f/8 Ritchey Chretien + CCD FLI PL4240, shows that this object is a comet with a diffuse coma about 20" in diameter.

Our confirmation image (click on it for a bigger version)

Amateur astronomer discovers kilometer-size asteroid

David Dickinson
Sky & Telescope
Fri, 11 Sep 2020 21:58 UTC

We have not yet found all the large, potentially hazardous near-Earth objects, as highlighted by the recent discovery of a kilometer-size asteroid.

Amateur astronomer Leonardo Amaral was scanning the skies on the night of August 27th, imaging a region in the constellation Indus, when he picked up a cosmic interloper: the asteroid 2020 QU₆.

Amaral used the 0.3-meter reflector at the Campo dos Amarais observatory near Sau Paulo, Brazil. The observatory had received a recent upgrade thanks to a Planetary Society grant.

Turns out, 2020 QU₆ is about a kilometer across — a surprising find given that most such large objects have been found and cataloged. The asteroid orbits the Sun once every 3.26 years on an orbit inclined 23.5° relative to the ecliptic plane. It poses no current threat to Earth, having passed within 40 million kilometers (24 million miles, more than 100 times the Earth-Moon distance) on September 10th. That's the closest the asteroid will come to Earth in the 21st century.

The long history of comet phobia

Jess Romeo
JSTOR Daily
Thu, 03 Sep 2020 18:20 UTC

Nowadays, the appearance of a comet, like the recently soaring NEOWISE, is likely to inspire wonder and excitement. But for much of human history, a comet was more likely to inspire blood-curdling fear.

"Almost always in classical times comets were regarded as portents, generally as warnings of dire events," writes historian Duane Koenig. (They were also sometimes "harbingers of happy things," like the birth of heroes, prophets, or kings.)

Ancient records show that thousands of years ago, "Persians and Koreans viewed comets as of evil nature and often [announced] war with the country in whose direction the tail pointed," writes Koenig. Over in Rome, comets were an object of fear and worship. Historian Geraldine Herbert-Brown finds that Pliny the Elder paid "particular attention to comets, and the terror they had caused humans in the course of history." According to Pliny, a comet would appear at "crucial intervals" starting in 49 BCE, "glaring terribly when Nero succeeded Claudius, and then continuously throughout Nero's principáte."

Comets — also called "bearded stars" — were consistently seen as bad news for rulers. Around 70 CE, the Roman emperor Vespasian was cautioned about a comet. "He contended the bearded star did not concern him because he was bald. It threatened his neighbor, the king of the Parthians, who was hairy," writes Koenig.

Meteor fireball spotted in background of news bulletin in Sydney

Andrew Bucklow
news.com.au
Thu, 03 Sep 2020 02:47 UTC

Channel 7 viewers in Sydney were stunned last night when a meteor shot into the Earth's atmosphere during the news.

Mark Ferguson was presenting the 6pm bulletin when a meteor was visible in the live feed of Sydney's skyline in the background.

Some eagle-eyed viewers noticed the object and posted about it on a Facebook group dedicated to meteor sightings.

Ferguson called into Sunrise this morning and spoke about the incident, telling the breakfast show hosts: "I didn't know too much at the exact time but within a few seconds of throwing to the commercial, Jess our cameraman quickly said, 'Mate, something has just flown behind you. I reckon it's a meteor.'

"We replayed it and had a good look and we couldn't believe it; what a shock!" Ferguson said.

Space rock turning into a comet observed for the first time

Lisa Goodman
Science News
Wed, 19 Aug 2020 18:25 UTC

© HEATHER ROPER/UNIV. OF ARIZONA
Space rocks called centaurs could someday become brilliant comets, like the one shown in this artist’s illustration. Astronomers have spotted a centaur that is expected to become a comet in about four decades.

Like the mythical half-human, half-horse creatures, centaurs in the solar system are hybrids between asteroids and comets. Now, astronomers have caught one morphing from one type of space rock to the other, potentially giving scientists an unprecedented chance to watch a comet form in real time in the decades to come.

"We have an opportunity here to see the birth of a comet as it starts to become active," says planetary scientist Kat Volk of the University of Arizona in Tucson.

Triple comet fly-pass imaged by SOHO

Karl Battams
Solar and Heliospheric Observatory (SOHO)
Fri, 14 Aug 2020 18:34 UTC

First appearances can be deceiving, and one of the latest comet discoveries by SOHO is the perfect example of that!

SOHO is no stranger to discovering new comets - via the NASA-funded Sungrazer Project, the observatory has discovered over 4,000 previously unknown comets since launch in 1995. Most of SOHO's comet discoveries can be categorized into families, or groups, the most famous being the "Kreutz" sungrazer group which accounts for over 85% of the Project discoveries. Only around 4% -some 175 comets- do not appear to belong to any known group or comet family. However, these are often among the most interesting comets and this most recent discovery -SOHO's 4,049th comet- was no exception!

The comet was first spotted on August 5th, 2020, by amateur astronomer Worachate Boonplod. At discovery, it was just a tiny faint smudge near the edge of the C3 coronagraph images recorded SOHO's Large Angle Spectrometric Coronagraph (LASCO) instrument. As it neared the Sun over the next day or so, the smudge became increasingly elongated, ultimately hinting that it may be two comets pretending to be one!

This was confirmed as the comets entered the narrower field of view of the LASCO C2 camera, where the improved resolution confirmed that not only was this more than one comet, it was actually THREE comets! The two main components are easy to spot, with the third a very faint, diffuse fragment following alongside the leading piece.

New Comet C/2020 O2 (Amaral)

Ernesto Guido
Remanzacco Blogspot
Mon, 03 Aug 2020 19:44 UTC

CBET 4822 & MPEC 2020-P10, issued on 2020, August 02, announce the discovery of a comet (magnitude ~18) by Leonardo S. Amaral (Rio de Janeiro, Brazil) on three 60-s CCD exposures taken on July 23 with a 0.3-m f/4 reflector. The new comet has been designated C/2020 O2 (Amaral).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 16 unfiltered exposures, 90 seconds each, obtained remotely on 2020, July 27.05 from X02 (Telescope Live, Chile) through a 0.6-m f/6.5 astrograph + CCD, shows that this object is a comet with a diffuse coma about 8" in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation image (click on it for a bigger version)

'Recovered' Halley-type comet 12P/Pons-Brooks may peak during America's next total solar eclipse in 2024

Jamie Carter
Forbes
Fri, 31 Jul 2020 09:33 UTC

As the world tries to see and photograph Comet NEOWISE (or check-out this week's extra-bright rings of Saturn), a comet similar to Halley's comet — last seen in 1954 — has been found by astronomers using a telescope in Arizona.

They've calculated that comet 12P/Pons-Brooks will return to the Solar System in April 2024 — which is when a total solar eclipse will next be observable from Mexico, the US and Canada.

The news comes just as Comet NEOWISE is glowing in the night skies for skywatchers in the northern hemisphere.

Comment: See also:

Largest meteorite discovered after sitting for decades in garden in Germany

Deutsche Welle
Wed, 15 Jul 2020 03:09 UTC

The out-of-this-world find is being hailed as a "scientific sensation." The meteorite was first dug up in 1989 and sat in a garden for decades before the homeowner shared his unusual rock with researchers.

Researchers announced Wednesday the discovery of the largest-known meteorite to have landed in Germany.

The unusual find had been sitting for years in a garden in the southwestern German town of Blaubeuren, according to a statement from the German Aerospace Center (DLR).

"The find has a mass of 30.26 kilograms [66.7 pounds], which makes it the largest stone meteorite ever found in Germany," meteorite expert Dieter Heinlein said.

DLR posted a video of researchers cutting into the boulder encasing the meteorite on Twitter, saying there was an "unbelievable story" behind the discovery.

Impact of meteorites led to life-giving amino acids on Earth

Tetsuya Ishikura
The Asahi Shimbun
Thu, 25 Jun 2020 10:58 UTC

© Provided byTohoku University associate professor Yoshihiro Furukawa
An illustration of how a meteorite struck Earth 4 billion years ago.

A simulation of how substances essential for living creatures were formed on Earth reinforces the theory that life started after meteorites rained down on the planet.

Living organisms are said to have emerged on Earth 4 billion years ago. A large number of meteorites are believed to have bombarded the planet 200 million years before and after the birth of life.

"Materials needed for the start of life may have been generated over long periods, offering a chance for life to appear," said Yoshihiro Furukawa, an associate professor of geochemistry at Tohoku University.

Furukawa and his colleagues primarily from the university put carbon dioxide, nitrogen, water and iron in a container to reproduce conditions of primordial times. The vessel was then struck with a piece of metal to simulate the impact from a meteorite.