Comets
Stacking of 15 unfiltered exposures, 240 seconds each, obtained remotely on 2021, July 30.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 8" arcsecond in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)
They're red, they're reasonably big, and they have no business being in the main asteroid belt, but their discovery confirms the complex conditions in place when the solar system was still forming.
New research published in the The Astrophysical Journal Letters details the discovery of two extremely red main-belt asteroids. Named 203 Pompeja and 269 Justitia, the asteroids have a redder spectral signature than any other asteroid in the main belt, that highly populated band of asteroids situated between the orbits of Mars and Jupiter. The new paper was led by Japan Aerospace Exploration Agency (JAXA) astronomer Sunao Hasegawa.
Importantly, these red asteroids resemble trans-Neptunian objects, that is, objects located farther away than Neptune, the most distant planet from the Sun (with no disrespect to dwarf planet Pluto). This could mean that 203 Pompeja and 269 Justitia formed way out there in the Kuiper Belt and then drifted inward when the solar system was still young. If confirmed, the new finding shows how chaotic the conditions were back then and that materials from different parts of the solar system would sometimes mix together.
The purpose of the study was to document the distribution and composition of large asteroids in the main belt. Large asteroids, especially those larger than 60 miles (100 km) in width, are likely survivors of the solar system's early days. By studying these objects, the scientists were hoping to catch a glimpse of what the conditions were like some 4 billion years ago.
Stacking of 16 unfiltered exposures, 180 seconds each, obtained remotely on 2021, July 14.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 9" arcsecond in diameter elongated toward PA 230 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)
Stacking of 28 unfiltered exposures, 60 seconds each, obtained remotely on 2021, July 10.1 from Z08 (Telescope Live, Oria) through a 0.7 m f/8 Ritchey Chretien + CCD, shows that this object is a comet with a compact coma about 8" arcsec in diameter and a tail 10" long in PA 250 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)
Over 800 miles from the impact site, massive ripples buried deep underground record the devastation wrought by an asteroid. The Chicxulub impact, the likely smoking gun for the extinction of the dinosaurs at the end of the Cretaceous, sent tsunamis tearing across the Gulf of Mexico. These giant waves left ripples in the undersea sediments as they passed and a new study has found what might be the largest "megaripples" on the planet.
The darkest dayLet's step back a moment. It has been around 40 years since the Chicxulub impact, located on the northern shores of the Yucatan Peninsula, was identified as the potential cause of the famed Cretaceous-Tertiary extinction (a.k.a., the K-t boundary). Since then, signs of this massive collision have been found across the planet. These include a layer of iridium from the asteroid, droplets of molten rock that rained down after the impact, wave deposits as far away as North Dakota and the charred remains of forest burned by the heat of the blast.

The comet is now known as Comet C/2014 UN271, or Bernardinelli-Bernstein after its discoverers, University of Pennsylvania graduate student Pedro Bernardinelli and astronomer Gary Bernstein.
According to the orbit calculated using data from 2014 to 2018, this object is likely to be a comet from the outer edge of the Oort Cloud. But 2014 UN271, despite its typically cometary orbit, appeared completely stellar in these archival images when it moved from 29 to 23 AU (for comparison, Pluto is 39 au from the Sun, on average). Below a simulation (made by T. Dunn) of the orbit of comet C/2014 UN271 showing it path in the Solar System from 1985 to 2049.
A few days after the discovery announcement, 2014 UN271 has been found to show cometary appearance in new CCD images obtained by observers at station codes L81 & K93.Basically this object, that was first seen as an asteroid of magnitude ~22 by DES in 2014 at a distance of 29 AU, approaching the Sun was growing his coma and tails. As of June 2021, it was 20 AU from the Sun shining at a magnitude ~20.After the discovery of the cometary coma, the new comet has been designated C/2014 UN271 (Bernardinelli-Bernstein). This comet will reach perihelion, its closest point to the Sun, in January 2031 at about ~11 AU away from the Sun.

Archaeological site in Arizona, US, with a distinctive black layer, indicating substantial environmental changes beginning about 10,800 BC, with impact debris at its base.
Their analysis backs up claims that an impact occurred prior to start of the Neolithic period in the so-called Fertile Crescent of southwest Asia.
During that time, humans in the region - which spans parts of modern-day countries such as Egypt, Iraq and Lebanon - switched from hunter-gatherer lifestyles to ones centred on agriculture and the creation of permanent settlements.
Catastrophic event
It is thought that the comet strike - known as the Younger Dryas impact - also wiped out many large animal species and ushered in a mini ice age that lasted more than 1,000 years.
Since it was proposed in 2007, the theory about the catastrophic comet strike has been the subject of heated debate and much academic research.
Now, researchers from the University of Edinburgh have reviewed evidence assessing the likelihood that an impact took place, and how the event may have unfolded.
Phaethon appealed to his father, who swore to prove his paternity by giving him whatever he wanted. Phaethon asked to be allowed to drive the chariot of the sun through the heavens for a single day. Helios, bound by his oath, had to let him make the attempt. Phaethon set off but was entirely unable to control the horses of the sun chariot, which came too near to the earth and began to scorch it. To prevent further damage, Zeus hurled a thunderbolt at Phaethon, who fell to the earth at the mouth of the Eridanus, a river later identified as the Po.Another cool thing for the Tusk is that I first learned the Phaethon myth may represent an actual cosmic event way back in 1995. My original guru — on all this stuff — is old buddy Bob Kobres. His neo-digital worldwide web page back in 95′ opened my eyes to the possibility that ancient myth isn't all just caveman campfire stories. Bob believed that long related tales of 'god's wrestling in the sky' were based on actual observations of physically realistic cosmic impacts.
Stacking of 35 unfiltered exposures, 120 seconds each, obtained remotely on 2021, June 02.4 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 15" arcsecond in diameter elongated toward PA 180 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation images (click on the images for a bigger version; made with TYCHO software by D. Parrott)
Stacking of 27 unfiltered exposures, 30 seconds each, obtained remotely on 2021, May 16.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 7" arcsecond in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation images (click on the images for a bigger version; made with TYCHO software by D. Parrott)











