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Comets

Comet 2

Space rock turning into a comet observed for the first time

Space Rock Turning into Comet
© 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.

Comet 2

Triple comet fly-pass imaged by SOHO

Sungrazer Comet
© ESA/NASA/SOHO/Karl Battams
Still shot identifying the comet and the fragments and an animation image below.
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.

Comet 2

New Comet C/2020 O2 (Amaral)

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)

Comet C/2020 O2 Amaral
© Remanzacco Blogspot

Telescope

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

Pons-Brooks
© Sygma via Getty Images
Comet 12P/Pons-Brooks is a Halley-type comet.
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:


Fireball 5

Largest meteorite discovered after sitting for decades in garden in Germany

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.
Meteorite, Blaubeuren
© Deutsche Welle
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.

Fireball 5

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

Meteorite Impact
© 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.

Fireball 2

Newly detected chi Phoenicids meteor shower

The ongoing night-time video surveillance of the night sky called "CAMS" has discovered a meteor shower caused by yet another unknown long-period comet that passed close to Earth's orbit in a past return. SETI Institute meteor astronomer Peter Jenniskens reports that this shower was briefly seen on June 10 by southern hemisphere networks of the CAMS project in New Zealand, Namibia and Chile (see the map for June 10 at this project website.
New Meteor Shower
© CAMS
The meteoroid stream is unusual in that its orbit is nearly exactly perpendicular to the plane of the planets, having an inclination of 90.2 +/- 1.0 degrees. The shower has received the name "chi Phoenicids" and has been added as number 1036 to the list of meteor shower names maintained by the International Astronomical Union. A telegram announcing the discovery (CBET 4798) was issued today.

Fireball 2

Krakatoa And The Great Comet of 1882: Exploring The Real Engine of 'Climate Change'

Eruption of Perbuatan volcano on Krakatoa Island, 26 August 1883.
© Dea Picture Library/De Agostini/Getty Images
Eruption of Perbuatan volcano on Krakatoa Island, 26 August 1883.
In May 1883, the captain aboard the German ship Elizabeth observed ash spewing above Krakatoa, an island in the Sunda Strait between Java and Sumatra in Indonesia. In the following weeks, other vessels reported hearing thunder and seeing incandescent clouds. Locals would also report earthquakes as small volcanic eruptions rumbled across the island.

Little did they know that these were the early signs of what would become one of the biggest volcanic eruptions in recorded history. Krakatoa erupted on Sunday August 26th 1883, sending volcanic dust as high as 24km (15miles) into the atmosphere. The following day on August 27th, two enormous explosions were heard as far away as Australia, with the final eruption destroying two-thirds of the island and triggering a powerful tsunami that wiped away entire settlements and was felt all the way across the Indian Ocean in South Africa. It's estimated that 36,000 people died in this natural disaster.

The eruption also had a marked impact on the global climate, sending a very large amount of sulfur dioxide (SO2) into the stratosphere, which led to a global increase in sulfuric acid concentration. This in turn increased cloud coverage that dimmed sunlight, sending global temperatures down by at least 0.4°C the following year. As submarine telegraph cables were already in use, news about the eruption was relayed rapidly across the globe, hitting the newspapers in New York, London and Paris by August 28th.

Comet 2

New Comet C/2020 K8 (CATALINA-ATLAS)

CBET 4796 & MPEC 2020-L46, issued on 2020, June 12, announce the independent discovery of a comet (magnitude ~19) of an apparently asteroidal object made on CCD images taken with the 0.68-m Schmidt telescope of the Catalina Sky Survey (on May 25, 28, and 29) and the 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program (on June 7). Then on June 8, R. Weryk reported the linkage of all of these tracklets, suggesting it might possibly be a comet based upon the astrometry. The object has been found to show cometary appearance subsequently by numerous CCD astrometrists at other observing sites after the object was posted on the Minor Planet Center's PCCP webpage. The new comet has been designated C/2020 K8 (CATALINA-ATLAS).
We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 29 unfiltered exposures, 60 seconds each, obtained remotely on 2020, June 09.4 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 irregular coma about 10" in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini).

Stacking of 24 unfiltered exposures, 57 seconds each, obtained remotely on 2020, June 10.4 from U69 (iTelescope, Auberry California) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a diffuse coma about 15" in diameter slightly elongated toward PA 358 (Observers A. Valvasori, E. Guido).

Our confirmation images (click here for a bigger version)
Comet C/2020 K8 Catalina-Atlas
© Remanzacco Blogspot

Question

India's Lake Lonar turns pink baffling scientists and locals

Maharashtra's Lonar Lake has turned pink overnight, leaving scientists and locals baffled about the reasons behind this change. Located in the Buldana district about 500 km from Mumbai, the Lonar crater had formed due to a meteorite, which hit the earth about 50,000 years ago.
Lonar Lake, India
© Outlook India
Water in the Lonar Lake, which has now turned Pink
This is the world's third-largest crater formed due to a meteorite strike. People in the area were considerably surprised when the lake's normal bluish-green water turned a pinkish red.