Asteroids, Comets, and Meteors

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Defending Earth From Cosmic Threats: Planetary Defense Experts Unite!
https://scitechdaily.com/defending-eart ... rts-unite/

By NASA April 13, 2023
Near Earth Asteroid Animation

The 8th IAA Planetary Defense Conference was held in Vienna with the aim of discussing ongoing efforts focused on addressing the asteroid impact hazard. Scientists, engineers, policymakers, and other Planetary Defense experts shared their respective knowledge and expertise to encourage coordination among global asteroid impact mitigation. The conference allowed attendees to hear from national policymakers on how to coordinate response to emergency events and what information would be needed from the Planetary Defense community about an impending asteroid impact. Ultimately, preventing an asteroid impact with Earth and avoiding a catastrophic natural disaster poses a complex problem that requires a multidisciplinary approach and international coordination.

The 8th IAA Planetary Defense Conference was held in Vienna to discuss efforts focused on addressing the asteroid impact hazard. Participants shared their knowledge and expertise to encourage coordination among global asteroid impact mitigation, and the conference also saw the release of the updated National Preparedness Strategy and Action Plan for Near-Earth Objects and Planetary Defense.

In a world where many global challenges exist, finding ways to respond to an as yet undiscovered asteroid that might one day impact Earth could seem like a lesser priority. While it is true there are currently no known asteroids of significant size on a collision trajectory with Earth, an asteroid impact with our planet has potential for catastrophic damage and could change the course of civilization as we know it. Equipped with this understanding, Planetary Defense experts around the globe convened last week in Vienna, Austria, for the 8th IAA Planetary Defense Conference (PDC) to discuss ongoing efforts focused on addressing the asteroid impact hazard.

[caltrek]

Mystery Rock That Damaged a New Jersey Home Could Be a Shooting Star
by Morgan McFall-Johnsen
May 11, 2023

Introduction:

(Science Alert) A grapefruit-sized metallic object fell from the sky, straight through the roof of a New Jersey home, and crashed into the floor of the bedroom on Monday, according to local reports.

Police who responded to the incident in Hopewell, New Jersey, believe the falling object may be a meteorite, possibly from the Eta Aquarids meteor shower, which peaked this weekend.

Nobody was home when the likely meteorite shot into the house, punching a hole in the roof and appearing to dent the floor, at about 1:15 pm local time, according to police.

"We are thinking it's a meteorite, came through here, hit the floor here because that's completely damaged, it ricocheted up to this part of the ceiling and then finally coming down and resting just on the floor there," Suzy Kop, who said the object fell into her father's bedroom, told CBS News Philadelphia.

"I did touch the thing because I just thought it was a random rock, I don't know, and it was warm," she said.

Read more here: https://www.sciencealert.com/mystery-r ... ing-star


The potential meteorite, in the bedroom where it landed.
(Hopewell Township Police Department/BI)

[wjfox]

The most dangerous asteroids of the next 1,000 years

3rd June 2023

Astronomers have mapped the paths of potentially hazardous 1 km+ asteroids between now and the year 3000 AD. At least 28 are found to have non-zero probabilities of a 'deep encounter' with Earth.

Read more: https://www.futuretimeline.net/blog/202 ... ranked.htm

[wjfox]

[caltrek]

First Known Boomerang Meteorite? This Space Rock Might Have Come From Earth
by Dr Alfredo Carpineti, PhD.
July 14, 2023

Introduction:

(IFL Science) Scientists might have found a truly weird rock. It looks like a meteorite, but its composition is very close to that of rocks that form deep in the ocean. And so, they have proposed a radical explanation: that this rock was knocked off the Earth, flew through space for maybe thousands of years, and then came back to Earth.

The meteorite was recovered in the Maghreb and purchased in Morocco in 2018. It has the designation Northwest Africa 13188 and a mass of 646 grams (23 ounces). Its chemical composition is dominated by two minerals, plagioclase and pyroxene, which make up about three-quarters of the meteorite. On top of that, the team looked at the isotopic composition of the rock, in particular of oxygen.

The chemical properties of elements are defined by the number of protons in their nucleus and, by consequence, the number of electrons that orbit said nucleus. But they can come in variants that are either lighter or heavier, which depends on the number of neutrons that are also present in the nucleus.

Oxygen is no exception. Almost all oxygen is O-16 (which has eight protons and eight neutrons), but there is a tiny percentage of O-17 and O-18 in nature. Different celestial bodies have different fractions of them, so scientists can use this like a fingerprint to track where an object is from. The minerals and the isotopic composition point to this rock being very much an Earthly one.

But that is not the full picture. The rock has a well-developed fusion crust. That is typical of meteorites. It would be difficult to fake it, though not impossible. But what really sells it as a meteorite is the concentration of isotopes of beryllium, helium, and neon that are consistent with a rock being exposed to cosmic rays for 10,000 years.

Read more here: https://www.iflscience.com/boomerang-m ... rth-69826

[wjfox]

[weatheriscool]

World's 1st mountaintop impact crater discovered in northeastern China
By Stephanie Pappas published about 19 hours ago
A two-peaked mountain in northeastern China is the site of the world's first confirmed mountaintop crater.

A nearly mile-wide (1.6 kilometer) divot in a Chinese mountaintop is actually an impact crater from a long-ago meteorite landing.

The newly discovered crater, located in northeastern China not far from the North Korean border, is the first confirmed mountaintop crater on Earth. Researchers aren't sure when the impact happened, but it left a circular depression and split the mountaintop into two peaks, known as Front Baijifeng and Rear Baijifeng.

The mountain peaks are littered with rock fragments known locally as "celestial stone," which turns out to be a scientifically accurate moniker. According to a new study, published Sept. 1 in the journal Matter and Radiation at Extremes, rocks on the peaks bear the telltale shock patterns of an impact with a space object.

The researchers were intrigued by the shape of the depression between the mountain's two peaks, which spans about 4,593 feet (1,400 meters), and by the debris-like scattering of large sandstone fragments on the mountain.

More:
https://www.space.com/earths-1st-mounta ... tern-china

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[firestar464]

old news

https://www.space.com/meteorite-impacts ... 2023-video

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OSIRIS-REx Successfully Drops Precious Pieces of Asteroid Bennu In Utah Desert
Dr Alfredo Carpineti
September 24, 2023

Introduction:

(IFL Science) SIRIS-REx has successfully completed its primary mission: to collect a sample of material from asteroid Bennu, pack it up into a capsule, and fly back to Earth. After seven years in space, and a few billion miles around the Sun (to save fuel), the orbits of our planet and the spacecraft crossed again, allowing the precious delivery of the first-ever US asteroid sample return to be made.

The cosmic package – signed, sealed, and delivered – landed safely in the US Air Force's Utah Test and Training Range on Sunday, September 24 at 8:52 am local time (2:52 pm UTC). It was collected in a helicopter in a well-rehearsed approach and taken to a special kitted-up room to avoid Earthly contamination. Protective items like the heat shield and back shell will be removed there and nitrogen will be used to remove oxygen and moisture from the sample canister.

Tomorrow morning a Boeing C-17 plane will fly the capsule down to NASA’s Johnson Space Center and that is where the fun begins.

Why was Bennu chosen for the asteroid sample?

Asteroid Bennu, the most dangerous known asteroid, is a window into the very beginning of the Solar System. A primitive space rock that has remained mostly unaltered for billions of years, studying its physical and chemical properties could give us hints about the building blocks of planets as they were forming 4.5 billion years ago.

Bennu is a rubble pile, loosely held together by gravity. OSIRIS-REx was able to estimate the density and porosity (the amount of empty space) of the whole asteroid but this can now be checked and compared with what is gleaned by the sample.

Read more here: https://www.iflscience.com/osiris-rex- ... t-70827



The sample is back on Earth.
Image Credit: NASA