Near-Earth objects and close calls

[Puma]

A meteor or earthquake?

Strong boom, jolt felt throughout San Diego County

Residents of San Diego County, U.S. and Tijuana, Mexico, began reporting the mysterious tremor and loud rumbling around 4 p.m. Monday.

On Monday, San Diegans throughout the county reported a loud boom and shaking as far away as Tijuana from Mexico.

Reports of tremors and loud bangs began around 4 p.m. Monday.

https://twitter.com/x/status/1630359825296109570

The USGS reported no earthquakes in the region, but the EMSC reported ground shaking in San Diego and Tijuana as a possible earthquake.

https://twitter.com/x/status/1630366110720696320

The U.S. Marine Corps confirmed it is conducting explosive ordnance training at the base Monday between 6 a.m. and midnight, but could not say whether the "booms" heard and felt between 3 and 4:30 p.m. were theirs.

Mexican authorities have not commented on the event.

Here are some reactions from the city:

https://twitter.com/x/status/1630356264470597632

https://twitter.com/x/status/1630357344680050689

¿Lo sentiste? Fuerte auge, sacudida se sintió en todo el condado de San Diego

Los residentes del condado de San Diego comenzaron a informar sobre el misterioso temblor y el fuerte estruendo alrededor de las 4 p.m. del lunes.

alertamundialinfo.com

 

[Puma]

This is a view of the fireball that flowed at 19:57:35 on February 28, 2023, as captured by a wide-angle camera pointed at the northern sky from my house in Hiratsuka. It was observed over a wide area in the Hokuriku and Kanto regions. It was a scattered meteor fireball.

Translation with Deepl

https://twitter.com/x/status/1630661461805793283

 

[Puma]

Meteor breaks up in the atmosphere

https://twitter.com/x/status/1630634030080094208

 

[Puma]

4 big asteroids are flying by Earth this week, but don't worry. They aren't getting too close.​

The near-Earth asteroids are all passing within 4.6 million miles (7.5 million kilometers) of our planet — close enough to make NASA's potentially hazardous asteroid (PHA) list — but none will come closer than 2.2 million miles (3.5 million km), according to NASA's weekly chart of asteroid passes(opens in new tab).

According to our sister site Livescience this week's big space rock flybys start with the asteroid 2012 DK31, which measures about 450 feet (137 meters) across — wider than a 40-story skyscraper is tall. It passed within 3 million miles (4.8 million km) of Earth on Monday (Feb. 27). While 2012 DK31's close approach distance meets NASA's PHA requirements, the agency has projected its path for the next 200 years and found it won't pose an impact risk to Earth, Livescience reported.

A second big asteroid called 2006 BE55 will fly by Earth today (Feb. 28) and is the one passing within 2.2 million miles of our planet. At 450 feet across, this asteroid is about the same size as 2023 DK31 and takes up to five years to orbit the Earth, according to Livescience

On Friday (March 3), two more big asteroids will pass the Earth, including the biggest of the week's four close-flying space rocks.

First, there's asteroid 2007 ED125. It's about 700 feet (213 m) across, making it the size of a large football stadium and the largest of the week's asteroid flybys. It will be nearly 2.8 million miles (4.4 million km) from Earth during its flyby, according to NASA. The second large asteroid is 2021 QW which is 250 feet (76 m) across and will pass within 3.3 million miles (5.3 million km) of Earth.

There are actually two more asteroids flying by Earth on Friday (March 3), but both are about the size of a large airplane — much smaller than 2007 ED125 and 2021 QW. One, called 2017 BM123, is 190 feet (58 m) wide and will pass within nearly 2.9 million miles (4.6 million km).

The other is a newly discovered asteroid called 2023 DX and will pass within 1.2 million miles (2 million km) of Earth. It was first detected on Monday (Feb. 27), according to NASA

NASA researchers and other scientists around the world regularly scan the skies for asteroids that may one day pose an impact risk to Earth. Space rocks larger than 492 feet (150 m) with orbits that pass within 4.6 million miles (7.4 million km) of Earth are considered to be potentially hazardous objects.

4 big asteroids are flying by Earth this week, but don't worry. They aren't getting too close.

None of them pose an impact risk.

www.space.com

 

[Puma]

Huge fireball with strong afterglow near California Bay Area

March 02, 2023.

NBC Bay Area viewers shared videos recorded early Thursday morning showing a meteor illuminating the pitch black sky.

One of the videos from a viewer in Vallejo shows a streak of light entering the frame before illuminating the night sky. Another video recorded by a viewer in San Ramon shows a similar view.

Astronomer Gerald McKeegan of the Chabot Space and Science Center confirmed that the fireball was in fact a meteor and said it probably started out as a small asteroid in space before burning up as it entered the atmosphere.

https://twitter.com/x/status/1631421329772785664

https://twitter.com/x/status/1631408755849203715

Enorme bola de fuego con fuerte resplandor cerca del área de la bahía de California

Bola de fuego visto sobre el cielo del área de la Bahía, este jueves 02 de marzo del 2023.

alertamundialinfo.com

 

[sToRmR1dR]

A bright fireball lit up the night sky over the Andalucía, Spain.

Published on Mar 3, 2023 (1:53)

 

[sToRmR1dR]

Bright fireball captured streaking in the sky above Morocco.

Published on Mar 4, 2023 (1:45)

 

[Puma]

Fireball over Popocatepetl Volcano

During the early morning hours of Thursday, March 2, 2023, at about 3:00 a.m., the monitoring cameras of the National Center for Disaster Prevention (Cenapred) captured the appearance of a fireball in the vicinity of the Popocatepetl volcano.

According to the images shared by Webcams de México, it appears that the meteor would have passed near the crater of "Don Goyo" (as the Volcano is known in Mexico)

Cae enorme bola de fuego con severo estruendo y resplandor sobre el volcán Popocatépetl

Captan espectacular bola de fuego cerca del cráter del volcán Popocatépetl este 02 de marzo del 2023.

alertamundialinfo.com

Wow! Direct and non-stop to the crater of the #volcano #Popocatépetl This is what a spectacular shooting star looks like this Thursday at dawn.
View #Tlamacas. Thanks #CENAPRED

https://twitter.com/x/status/1631278293134594048

 

[sToRmR1dR]

A bright fireball lit up the night sky over the Andalucía, Spain.

Published on Mar 9, 2023 (1:46)

 

[sToRmR1dR]

A bright fireball lit up the night sky over the Madrid and Segovia, Spain.

Published on Mar 12, 2023 (2:05)

 

[sToRmR1dR]

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

Published on Mar 16, 2023 (1:55)

 

[Voyageur]

Wow! Direct and non-stop to the crater of the #volcano #Popocatépetl This is what a spectacular shooting star looks like this Thursday at dawn.

Wow indeed:

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

That is a busy sky (Mar 3, 4, 9, 12, 16) in and around Spain.

 

[thorbiorn]

Earlier in March

Fireball over Denmark - meteorites may have fallen in Jutland
Aarhus University is seeking help from people who have either seen the meteor - or have found one of the meteorites.

Fireball seen from Silkeborg 4 March. Video: Jesper Grønne

The article has a video, but I can't embed.

Anders Brandt
YESTERDAY AT 18:00

A fireball could be seen in the sky in large parts of Denmark on the night of Saturday 4 March, and the remains of it may have fallen to the ground in southern Central Jutland as one or more meteorites.

The meteor hit the Earth's atmosphere at an altitude of 90 kilometers at a speed of almost 65,000 kilometers per hour and immediately began to burn - and could then be seen as a fireball.

When it reached an altitude of 30 kilometers just 4.5 seconds later, the fireball extinguished due to the deceleration and cooling.

It was caught by cameras set up for the purpose in Denmark, Norway and Germany, and with the help of a total of nine cameras, the trajectory of the fireball could be determined.

There are pictures from the Norwegian meteor network and the Danish
[The Swedish Allsky Meteor Network exists, but does not work as smoothly as the two others.]
From Kristiansand in Norway there was a colour image:
All these spectacular fireballs, but where are the meteorites? Good observations can help to calculate the trajectory and make estimates of whether there might be falls or not. On March 4, there was a fireball over Denmark,
From Kristiansand in Norway there was a colour image:

All these spectacular fireballs, but where are the meteorites? Good observations can help to calculate the trajectory and make estimates of whether there might be falls or not. On March 4, there was a fireball over Denmark,
From Kristiansand in Norway there was a colour image:

and this:

 

[Puma]

NEO 2023 DZ2 discovered about a month ago on a direct path with earth. It is large and has been given a warning scale of danger of 9 according to the video but officially is 7

Small-Body Database Lookup

Asteroid 2023 DZ2
Closest approach Date: March 25, 2023
Miss Distance: 0.5 Lunar Distance
Velocity: 7.8 Km/s
Diameter: 59 meters
SpaceWeather.com

200-foot asteroid 2023 DZ2 to pass closer than moon​

Yet another newly discovered space rock will safely zip past Earth, this one on March 25, 2023. It’ll sweep by at about half the Earth-moon distance. Astronomers at the observatory of La Palma, in the Canary Islands, Spain, discovered the asteroid in late February, 2023. And amateur astronomers might get a glimpse of the asteroid as it speeds past. See the charts at the bottom of this post.

Closest approach to Earth is thought to occur at around 19:52 UTC (3:52 p.m. EDT) on March 25. But the exact time and other details might be updated as more observations come in.

The asteroid has been labeled 2023 DZ2. It’s part of the Apollo family of asteroids. Current estimates put 2023 DZ2’s size at about 210 feet (64 meters) in diameter.

As of March 18, 2023, there were 94 observations of the new asteroid’s orbit spanning 63 days. New observations will better define the space rock’s orbit and should allow scientists to get a more precise estimate of its size, which could be between 144 and 325 feet (44 and 99 meters) in diameter.

For comparison, the asteroid that entered over Chelyabinsk, Russia, in February 2013 was a space rock around 65 feet (20 meters) in diameter. Watch a video of size comparisons in asteroids here.

2023 DZ2 is classified as a NEO (Near Earth Object). It orbits the sun every 3.17 years.

Small risk of impact in 2026​

As is the case with many newly discovered asteroids – whose orbits are incompletely known – preliminary analysis of the space rock’s trajectory suggests a very unlikely 1-in-430 chance that the asteroid will impact Earth on March 27, 2026.

But – with further observations – it’s likely astronomers will rule out even this small risk.

| EarthSky

earthsky.org

 

[thorbiorn]

On Sott, it is sometimes reported which color the fireball or meteor had. Below are a couple of excerpts that may help explaining the observations of different colours.

That was three years ago, below is more on:
The colours of meteors and fireballs
First, there is an image of the colours and their wavelengths, as it will make it easier to interpret the information in the diagrams:

The paper Catalogue of representative meteor spectra has a few interesting findings:

They explain:

The appearance of the spectrum depends not only on the temperature, but also on the speed of the meteor. As an example of a spectrum of a fast (50.7 km s−1) meteor, the spectrum SX457 is given in Fig. 6. In contrast, in Fig. 7 the example of a slow (24.5 km s−1) meteor is presented (the spectrum SX1206). Both meteors had a similar visual magnitude (≈+1 mag). The atmospheric lines of O I, N I, the nitrogen bands N2, and the forbidden green oxygen line [O I] are much brighter in fast meteors and cause brighter red and infrared parts of the spectrum of a fast meteor than in the spectrum of a slow meteor. The only atmospheric line, eminent in the spectrum SX1206, is the brightest oxygen line O I at 7774 Å.

The diagram below shows that a fast meteor generally begins to light up at a higher altitude:

Different colours can indicate different elements
The American Meteor Society’s filter bank spectroscopy project has this table:

However, it gets more complicated:

For extremely bright fireballs and bolides, where many more emission lines are seen and their closer proximity in wavelength may cause mixing in a pass band, this concept breaks down. But the goal of this work is to push the limiting magnitude of spectra to the fainter meteor regime than typically captured with grating spectroscopy, thus operating at intensity levels where one is not expected to see a lot of the weaker emission lines.

One example about fireballs:

Bright Perseid fireball with exceptional beginning height of 170 km observed by different techniques
[...]
Abstract

We report multi-instrumental observation of a bright fireball belonging to the Perseid meteor shower, which was recorded simultaneously by 11 all-sky photographic cameras, one high-resolution 300 mm photographic camera, two digital all-sky cameras, one wide-field digital camera, and two analog image-intensified video cameras on 12 August in 2012 at 22:29:46 UT. An exceptional beginning height of 170 km makes this fireball the highest Perseid ever observed and the highest meteor ever observed with precise atmospheric trajectory and heliocentric orbit not belonging to the Leonid shower. Moreover, one spectral video camera recorded the spectrum of the fireball. The spectrum shows only atmospheric emissions of O, N, and N2 above 130 km. Below 110 km, the spectrum is not markedly different from other Perseid fireballs. The spectrum of the persistent train was also recorded, and a double-station observation of the persistent train provided its vertical and horizontal motion.

If a fireball begins to light up at an altitude of 170 km, it will be visible from quite far away, provided the sky is clear.
Here is another article:
EMISSION SPECTRA OF TAURID FIREBALLS OBSERVED IN 2015.
From it there are three diagrams:

And they conclude:

We have presented a sample of three meteor emission spectra recorded during our monitoring of the activity of the Northern and Southern Taurid meteor showers in 2015. As a consequence of the enhanced Taurid fireball activity produced that year, we obtained over 40 emission spectra. Some afterglow spectra were also recorded. These signals are dominated by the emission associated with different Fe I multiplets. The emissions of the Na I-1 doublet and the Mg I-2 triplet are also very noticeable, and the contributions of Ca II-1 and Ca I-2 have been also identified. The detailed analysis of these spectra will provide information about the chemical nature of the progenitor meteoroids and about the processes that take place in Taurid fireball persistent trains.

So much for colours, but to finish with an update, only small fireballs have been recorded in 2023 by NASA. They range between 0.073 and 0.57 kt of TNT. For comparison, in 2022, the largest was 7 kt.