Near-Earth objects and close calls

A bright fireball streaked through the night sky over the Mediterranean Sea.

Published on Mar 15, 2021 (1:04)

Just to highlight this dates from March 15th (rather than May) and already noted on Sott -

 
A newly-discovered asteroid made a close approach to Earth on May 14, 2021.

Posted by Teo Blašković on May 17, 2021

 
HUGE BOLID #SPMN160521 recorded last night at 22h32m06s from multiple stations in our research network. While we work on its reconstruction we share a selection of spectacular videos. This one captured by Cèsar Guasch
@MeteoSantMateu from Sant Mateu
2) The racing car #SPMN160521 it was reported by various visual testimonies and captured from the Observ. by La Murta in #Murcia by Sensi Pastor and José A. de los Reyes. We share that video below and you have the general details in the list:http://spmn.uji.es/ESP/SPMNlist.html
3) HOW DID THAT BOLID SEE #SPMN160521 FULL COLOR? Well, take a good look at that intense emerald blue and those flares captured by one of the color cameras from our station in #Benicàssim (Castelló) operated by Vicent Ibáñez (
@vicent_ibanyez
)

Snip:
We now know most of these come from the main asteroid belt – a region between Mars and Jupiter.

But might some of them have come not from asteroids, but from comets that originated in the outer reaches of the Solar System? What would such meteorites be like, and how would we find them?

Skipping Down:

Our research, published in The Planetary Science Journal, scoured every fireball tracked by the DFN between 2014 and 2020, in search of possible cometary meteorites. In total, there were 50 fireballs that came from comet-like orbits not associated with a meteor shower.

SD:

The next question is: if all meteorites are asteroidal, how did some of them end up in such weird, comet-like orbits?

For this to be possible, debris from the main asteroid belt must have been knocked from its original orbit by a collision, close gravitational encounter, or some other mechanism.

Meteorites have given us our most profound insights into the formation and evolution of our solar system. However, it is now clear that these samples represent only part of the whole picture. It is definitely an argument for a sample-return mission to a comet. It’s also testament to the knowledge we can gain from tracking fireballs and the meteorites they sometimes leave behind.

May 16, 2021 Yangquan Shanxi CHINA (Friday, May 7th 2021 around 16:42 UT.)
 
New meteor impact crater discovered on Mars on 12th March. About 13 meters in diameter.


New meteor impact crater discovered on Mars




Andy Tomaswick
Universe Today
Mon, 17 May 2021 12:00 UTC




meteor crater mars

Meteors hit much harder on Mars than they do on the Earth. Lack of atmosphere obviously contributes to that, but its proximity to the asteroid belt also makes the red planet a more likely target for some gravitationally disturbed rock to run into. Now that we have a satellite infrastructure consistently monitoring Mars, we are able to capture the aftermath of what happens when it is pummeled by space debris, and the results can be dramatic.


Comment: Jupiter not a shield but is flinging comets toward Earth says new research


One powerful tool in that impact hunting toolkit is the Mars Reconnaissance Orbiter (MRO). It has a variety of instruments on it that make it possible to both track down areas of interest and then follow up with high resolution imagery, incluidng HiRISE, the camera that took the picture above. That is exactly what happened with a new crater that the satellite noticed on one of its flybys.


Anton Petrov discusses Martian crater formation.
Credit: Anton Petrov YouTube Channel
The new crater shows up as a bright spot, which scientists theorize might be shallow subsurface materials that were blasted into the open on impact. This contrasts with many new craters, which show up as dark spots as dust from the ejecta is covered in a darker material. Those bright spots are significantly bright in the attached image though, as it was color enhanced in post processing.

The new crater is 13m in diameter, and shows up spectacularly on the newly released image. It goes to show just how active our solar system still is, and how a little rock can make a big impact when there's little to nothing to stop it.

Learn More:
HiRISE - A New Impact Crater with Bright Ejecta
UT - The Colorful Walls of an Exposed Impact Crater on Mars
UT - The "Happy Face Crater" on Mars Has Been Changing Right Before Our Eyes

Lead Image:
New HiRISE Picture of the Day showing a 13m new crater on Mars.
Credit: NASA / JPL / UArizona
 
Last edited:
Scott Manley theorizes the effects of the Keyhole effect (on close approach asteroid's).
And the possibilities of natural forces being a game changer to the current data (of close approach space rocks prediction's).

There are thousands of asteroids which regularly come close to the earth and have a chance of one day hitting the Earth, potentially causing a major disaster. However despite the laws of physics enabling us to predict the motion of the planets with precision for thousands of years, we can't do the same for these asteroids, because they all end up having a close approach with the Earth that makes it almost impossible to predict their orbit after this. Thanks to Rusty Schweickart for suggesting this subject.

Thanks to Scott Vaughen for creating the hyperbolic orbit tool.

An asteroid whose orbit is wholly within Venus’s
More close-in asteroids could be discovered if their orbits are as stable as two new studies suggest.
16 Apr 2020 in Research & Technology
On 4 January 2020, astronomers using the Zwicky Transient Facility at Palomar Observatory discovered a new asteroid, 2020 AV2. So close is its orbit to the Sun that the observing window shut just 19 days later. Nevertheless, enough measurements were taken to indicate that 2020 AV2 spends the entirety of its 151.2-day, roughly circular orbit inside the orbit of Venus. At 0.6538 ± 0.0001 AU, its aphelion (farthest distance from the Sun) is the smallest ever determined for an asteroid.

The orbit of 2020 AV2 is known with sufficient accuracy that two independent teams could infer the object’s dynamical past and future. Their newly published analyses agree that 2020 AV2 is close to an orbital resonance with Venus. If other asteroids occupy similar orbits, they could constitute a large and stable population that awaits discovery.

One team consists of the brothers Carlos de la Fuente Marcos and Raúl de la Fuente Marcos, both of Complutense University of Madrid in Spain. The other is Sarah Greenstreet of the B612 Asteroid Institute and the University of Washington in Seattle. Each used a different, complementary approach to tackle the sensitivity to perturbations of satellites in many-body, self-gravitating systems. The de la Fuentes calculated orbits for the central set of observationally derived orbital parameters and for three pairs of increasingly outlying sets of parameters. Greenstreet also calculated an orbit for the central set of observationally derived parameters as well as for 9900 sets of parameters assigned from a Gaussian distribution within the observed uncertainties.

Asteroid 2020 AV2 likely originated in the main asteroid belt between Mars and Jupiter. A type of orbital resonance, ν6, made the orbit of 2020 AV2 ever more eccentric until the asteroid experienced close encounters with Earth, Venus, and Mercury. Despite the drastic changes in trajectory wrought by close encounters, both analyses indicate that 2020 AV2 appears to be in or close to the 3:2 orbital resonance with Venus. The stability of the resonance could safeguard the asteroid’s orbit from further close encounters with Venus. An additional source of stability, the analyses suggest, could come from correlated oscillations in inclination and eccentricity known as von Zeipel-Lidov-Kozai oscillations.

Asteroids whose orbits lie within Earth’s are known as Atiras, after the Earth goddess of Pawnee mythology. Twenty-one Atiras have been discovered since the first one, (163693) Atira, was confirmed in 2003. Prefixing V for Venus yields Vatira, which is what astronomers unofficially call 2020 AV2.

Detecting other Vatiras is challenging because of their proximity to the Sun. Few ground-based telescopes can point low enough in the early morning or late evening to observe them. The de la Fuentes’ and Greenstreet’s analyses suggest the search for a new and possibly large population of Sun-orbiting objects could pay off. (C. de la Fuente Marcos, R. de la Fuente Marcos, Mon. Not. R. Astron. Soc. 494, L6, 2020; S. Greenstreet, Mon. Not. R. Astron. Soc. 493, L129, 2020; thumbnail illustration credit: NASA/JPL.)

Refences:
The first Vatira, 2020 AV2, may point to asteroids resembling Earth’s mantle.
Nola Redd Jul. 1, 2020 , 12:20 PM


SideNote reading:
Guidebook to the Geology of Barringer Meteorite Crater, Arizona (a.k.a. Meteor Crater) 2nd edition
by David A. Kring ©2017, Lunar and Planetary InstituteLPI Contribution No. 204 Complete volume(164 MB)
Chapter 9: Projectile (3.35 MB)
Chapter 10: Trajectory (171 K)
Chapter 11: Energy of Impact (165 K)
Chapter 12: Age of the Crater (169 K)

Fr. Translation
Animations of the Impact Blast Zone
 
A newly-discovered asteroid made a close approach to Earth on May 30, 2021.

Posted by Teo Blašković on May 31, 2021


A newly-discovered asteroid made a close approach to Earth on May 31, 2021.

Posted by Teo Blašković on May 31, 2021


Bright fireball captured streaking in the sky above Indian lake, Ohio.

 
Back
Top Bottom