Near-Earth objects and close calls


FOTCM Member
Since NASA announced recently that Near-Earth objects (NEOs) are on the rise since 20 years, it could be worth to keep some of the new discoveries on the record. It feels like if every week a new and unknown object crossed closely the earth and was discovered just some hours before.

The newest discovery for this week (10. August) was asteroid 2018 PD20 a 15 m tall asteroid that came as close as 33.210 km (20,636 miles).

Asteroid seen after it makes the closest flyby of the year
The existence of an odd pair of asteroids points to an early period of chaos in the young solar system. One that ended 600 million years earlier than previously thought.

Much like the famed Trojan horse, Jupiter's Trojan asteroids are hiding a secret.

According to a new study published in the journal Nature Astronomy, the existence of a bound pair of "Trojan asteroids" trapped in a stable orbit near Jupiter suggests the early solar system was shaken up by a battle between the giant planets much earlier than astronomers previously thought.

"The Trojans were likely captured during a dramatic period of dynamic instability when a skirmish between the solar system's giant planets — Jupiter, Saturn, Uranus, and Neptune — occurred," said lead author David Nesvorny of the Southwest Research Institute (SwRI) in a press release.

According to the study, within just 100 million years of the solar system's formation, the giant planets had already jostled for position. During the fray, Jupiter jumped inward a hair, while Uranus and Neptune were pushed away from the Sun toward an ancient collection of small bodies located on the outskirts of the solar system. These small bodies are known as Kuiper Belt objects, and can include comets, asteroids, and everything between.

With the new addition of Uranus and Neptune, the still-forming outer solar system got thrown out of whack. "Many small bodies of this primordial Kuiper Belt were scattered inwards," said Nesvorny. "And a few of those became trapped as Trojan asteroids."


Jupiter's Trojan asteroids are divided into two main groups. Asteroids in the Greek Camp (leading Jupiter at L4) are named after Greek heroes, while those in the Trojan Camp (trailing Jupiter at L5) are named after Trojan heroes. (Astronomy: Roen Kelly)

The leading camp of Trojan asteroids, known as the "Greek Camp," is located at Jupiter's L4 Lagrangian point (think "L4 for forward"), which is a special point in a planet's orbit where competing gravitational forces from the Sun and the planet perfectly balance each other. Among the trailing population of Trojans — located at L5 and referred to as the "Trojan Camp" — hides a strange, co-orbiting pair of twin Trojans named Patroclus and Menoetius. The pebble-pile asteroids that make up this binary couple are each about 80 miles (130 kilometers) wide and are remnants from the very earliest moments of the solar system's formation.

"Observations of today's Kuiper Belt show that binaries like these were quite common in ancient times," said co-author William Bottke of SwRI's Space Studies Department. "Only a few of them now exist within the orbit of Neptune. The question is how to interpret the survivors."

Many existing models that attempt to explain how the solar system evolved suggest that planetary migration took place roughly 700 million years after the Sun formed. This is partly because the migration of the planets is often linked to a period known as Late Heavy Bombardment (LHB) — a cataclysmic era beginning about 3.9 billion years ago. During LHB, huge numbers of asteroids tirelessly shelled the inner planets and the Moon, leaving behind many craters that we can still see today.

However, although LHB is often associated with planetary migration, the authors of the new study argue that the two events occurred during distinct epochs separated by over half a billion years.


This animation shows how the Trojans Patroclus and Menoetius orbit around one another as they circle the Sun behind Jupiter. New research suggests that, because the fragile binary pair is still intact, it must have entered Jupiter's Trojan Camp much earlier than previously though

According to the study, if the planets didn't migrate until 700 million years after the formation of the Sun, then there is very little chance the fragile Patroclus-Menoetius Trojan could have survived. Instead, the researchers claim (and support with new models and simulations) that Patroclus and Menoetius were already bound together and in place near Jupiter long before LHB occurred. Since the binary pair was most likely captured by Jupiter during its tussle with the other giants, the researchers argue the very existence of the Trojan pair strongly suggests the planets migrated very early on, within about 100 million years of the solar system's formation.

If shown to be true, this new model has dramatic implications for LHB.

Many large craters observed on the Moon, Mercury, and Mars are typically associated with impacts from outer-solar-system asteroids during LHB. But if the planets migrated hundreds of millions of years before LHB occurred, then where did impacting asteroids come from?
One possibility is that the crater-causing impactors that struck the inner planets did not originate from the outer solar system at all. Instead, they could have come directly from the rocky leftovers of the newly formed terrestrial planets.

Although there are still many mysteries regarding the Trojan asteroids that remain to be solved, an ambitious NASA mission will help lift the veil. Scheduled for launch in 2021, NASA's Lucy mission will soon embark on a meandering 12-year journey that will take it to six Trojan asteroids, as well as one main-belt asteroid for good measure. Fittingly, Lucy's last scheduled target, which it should reach in March of 2033, is none other than the binary pair of Patroclus and Menoetius.

So keep an eye out, because over the next 15 years, we are primed to learn a great deal about the hidden troops that make up Jupiter's Trojans. And they likely have some more secrets to share.

4 newly detected asteroids within 1 lunar distance, including second closest of the year
Snip: Posted by TW on November 19, 2018
Four new <1 LD Apollo-class asteroids were detected at Catalina and Mt. Lemmon sky surveys on November 17, 2018. Three of them, including the second closest of the year, flew past our planet on November 16 and 18 while the fourth is expected at 23:23 UTC today, November 19. The total number of known <1LD asteroids this year now stands at 66.

Asteroid 2018 WH

Asteroid 2018 WH was first observed at Catalina Sky Survey, near Tucson, Arizona on November 17. Its estimated diameter is between 2.8 and 6.3 m (9 - 20 feet).

The object made its closest approach to Earth at 05:49 UTC on November 16 at a distance of 0.50 LD / 0.00128 AU (191 485 km / 118 983 miles) and a speed (relative to the Earth) of 7.81 km/s.

'Mysterious' objects hit two cars in Scottsdale, Arizona --
Fri, 16 Nov 2018 18:13 UTC Video / 02:46

American Meteor Society - Fireball event
Events in 2018 5004-2018
AMS received one report about a fireball seen over GA on Saturday, November 17th 2018 around 09:20
Thanks for the video, c.a. Observed a fireball/neo on Saturday or Sunday night driving home from work - and live close to the Georgia state line on the North Carolina side. So that means that this area has been seeing more than just a one-off I think (unless it was the same one in the video). It's the second time I've seen something like this in the area in the last couple of years; bright, streaking low in the sky and as plain as day.
Thanks for the video, c.a. Observed a fireball/neo on Saturday or Sunday night driving home from work - and live close to the Georgia state line on the North Carolina side. So that means that this area has been seeing more than just a one-off I think (unless it was the same one in the video). It's the second time I've seen something like this in the area in the last couple of years; bright, streaking low in the sky and as plain as day.

Speaking of which, I too saw a fireball around 2 weeks ago. We were watching a JP interview on TV and I saw a green one through my window. Pretty!
Translated from Spanish by Microsoft
Above the constellation of the oven approaching each day to the Taurus, does not come out in Stellarium 😥 I hope this image will serve you.

From Instituto de Astrofísica de Andalucía, IAA-CSIC via Manu Garcia of IAC: “The complex dynamics of the ring systems miniature solar system”
richardmitnick 8:50 pm on November 21, 2018
From Manu Garcia, a friend from IAC. Ring systems around small celestial bodies.

Result of a numerical integration showing the development of seven hundred particles orbiting an elongated body size and shape similar to Chariclo (an ellipsoid with the major axes of 314 x 278 x 172 kilometers). The particles are subject to a radial dissipative force that simulates the effect of collisions. After three months (upper panel), most of the particles within the corotación (190 kilometers from the center of Chariclo) fell on the body. After a year (central panel), it has been emptied the internal area, and after a year (lower panel) particles continue their migration to the outer areas.

The discovery of rings around the Solar System bodies that are not planets, like the dwarf planet Haumea or centaur Chariclo, showed that it is most common structures than previously thought. Work in the Institute of Astrophysics of Andalusia (IAA-CSIC) participates, analyzes the complex dynamics of these rings in miniature.

Until five years ago it was thought that the rings were unique features of large gaseous planets, like Saturn or Uranus, but the discovery of rings around no planetary bodies in the solar system forced to review these structures, apparently more common than is I thought. Now, a job in which the Institute of Astrophysics of Andalusia (IAA-CSIC) participates has analyzed the dynamics of these ring systems in miniature, more complex in some cases than the giant planets because of the terrain or elongated shape of these bodies.

In 2013 and 2017, respectively, two bodies of the solar system entered the small group of objects ring: Chariclo, the largest of a population of objects known as centaur, which are among Jupiter and Neptune and share features with both comets as asteroids; and Haumea, a dwarf planet beyond Neptune with ellipsoidal shape and size, most side, similar to Pluto.


The complex dynamics of the ring systems miniature solar system. Image author transneptunian object Haumea.

Both have narrow and confined rings, suggesting the existence of “satellites shepherds” that contribute to the rings remain confined as those seen around Saturn and Uranus. However, there is an important difference between giant planets and no planetary bodies, since the latter can show very irregular shapes: may have reliefs such as craters or mountains, nonexistent in the gaseous planets, or show an elongated shape (Haumea, for example, it has a flattened shape as a rugby ball).

“In this study we showed that these deformations or irregularities create gravitational resonances between the body and the ring particles that cause synchronous orbit (or corotation), wherein the particles have an orbital period equal to the rotation of the central body, is empty: the particles of the disc that are within the corotation fall toward the central object and, conversely, that are outside are pushed outward beyond the 1: 2 resonance (in which complete a revolution around the body at the time this tour twice on itself), “said Pablo Santos-Sanz, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC), which participates in the work.

The time scales associated with the migration of the particles of the disk are small, a few years in the case of elongated bodies, as Haumea. For a spherical body with an equatorial mountain five kilometers, the area co-rotation can be emptied in less than a million years, a period of very short time compared to the age of the Solar System.

These findings are confirmed in the known objects: rings Chariclo and Haumea are four hundred and two thousand two hundred and ninety kilometers outside its resonances 1: 2, which occur three hundred and fifty kilometers respectively seven hundred thou.

Another prediction paper presented affects the rotation of the body, to be rotated very quickly on itself so that the particles at that distance are kept forming a stable ring or, otherwise, would vent further, to finish perhaps forming satellites . For frozen bodies as Chariclo and Haumea rotation period must be less than seven hours, which is also true, and rotating on themselves seven and four hours, respectively.

“This is a field still new study because five years ago we did not know that these objects could present rings. These mechanisms could also explain the formation of satellites around certain bodies through the migration of a disk initially more next to the object, “says Pablo Santos-Sanz (IAA-CSIC).

Science paper:
Ring around non-axisymmetric dynamics with application to Chariklo bodies and Haumea
Nature Astronomy

See the full article here.


Welcome to the Instituto de Astrofísica de Andalucía (IAA). The IAA is an institute of Consejo Superior de Investigaciones Científicas (CSIC) in Granada – Andalucía. The activities of the IAA (CSIC) are related to research in the field of Astrophysics and the development of instruments for telescopes and space vehicles.

These webpages are intended to present our activities as well as useful information both for other professional institutions devoted to astrophysics research as well as for those interested in learning something more about the IAA and astrophysics in general.

From the front page on, an explanation is provided of the structure and organization of the IAA, followed by general information concerning our technological and scientific research in addition to all the activities we consider of general interest.

The pages of each department provide basic information: the staff, research lines, projects under way and research results. The navigator will also find more specific and varied information on each of the individual pages of the IAA staff.

The IAA has as its general scientific objective to help increase the bulk of knowledge about our universe, from the closest at hand, our solar system, to an overall scale of the entire universe, improving descriptions and analysing the physical processes that take place there. The nature of this aim demands a multi-disciplinary approach, requiring a combination of theory, observation and technology in different areas of physics and engineering. Although the IAA is a centre for pursuing basic science, we are aware of the role that astrophysics plays as a user and producer of new technologies.

To achieve our overarching objective, different scientific programmes are being undertaken with specific aims and timetables, encompassing four large areas of astrophysics: the solar system; star formation, structure and evolution; galaxy structure and evolution; and cosmology. Basic science has been and continues to be the motor for training scientific and technical staff, as well as for stimulating the development of other disciplines. The history of the IAA clearly depicts the observational function of the centre.

The telescopes installed in the Observatorio de Sierra Nevada (OSN), reflect a scientific policy with the clear objective of ensuring continued access to observational means to undertake far-reaching scientific projects. This fact adds singularity to the centre and at the same time offers the challenge and incentive for research at the IAA. The design and construction of instruments for the OSN, as well as others to be carried in special space vehicles, not only serve as support for basic research by the different teams of the IAA, but also represent activity of prime importance for the appropriate combination of research and development.

The Institute of Astrophysics of Andalusia (Spanish: Instituto de Astrofísica de Andalucía, IAA-CSIC) is a research institute funded by the High Council of Scientific Research of the Spanish government Consejo Superior de Investigaciones Científicas (CSIC), and is located in Granada, Andalusia, Spain. IAA activities are related to research in the field of astrophysics, and instrument development both for ground-based telescopes and for space missions. Scientific research at the Institute covers the solar system, star formation, stellar structure and evolution, galaxy formation and evolution and cosmology. The IAA was created as a CSIC research institute in July 1975. Presently, the IAA operates the Sierra Nevada Observatory, and (jointly with the also the Max-Planck Institute of Heidelberg) the Calar Alto Observatory.


An artist’s conception of a distant Solar System Planet X, which could be shaping the orbits of smaller extremely distant outer Solar System objects like 2015 TG387 discovered by a team of Carnegie’s Scott Sheppard, Northern Arizona University’s Chad Trujillo, and the University of Hawaii’s David Tholen.

Our outer solar system is a dark, cold place that's difficult to explore from Earth. But careful observations are turning up more and more evidence for a massive planet we just haven't seen yet.
By Nathaniel Scharping | Published: Tuesday, October 2, 2018

Far beyond the orbits of the solar system’s eight planets, astronomers have found another object they’ve nicknamed “The Goblin.” It’s a small world traveling a lonely path through the outer reaches of our cosmic neighborhood, and it joins a small club of dwarf planets and other planet-like objects out beyond Neptune. Most excitingly, the object’s movements fit into previous theories regarding a possible “Planet X” hiding far away in our solar system, and could help astronomers to find it.

Distant Objects

The dwarf planet’s official name is 2015 TG387, and it was discovered three years ago by a team of researchers using the Subaru telescope atop Mauna Kea in Hawaii. Led by Scott Sheppard of the Carnegie Institution for Science, the astronomers were scanning broad swathes of the sky in search of faint glimmers that might betray new objects in the solar system. Sheppard, who found another similar object just four years ago, spent the next three years confirming the original sighting with his team and announced the find today in the Astronomical Journal.

The dwarf planet is about 190 miles in diameter based on preliminary measurements. Pluto, for example, is about 1,500 miles in diameter. The Goblin is one of just a few objects whose elliptical orbits never take them closer to the sun than Neptune. Just two, 2012 VP113 and 90377 Sedna have a perihelion (the point of an object’s orbit closest to the sun) farther out than The Goblin, and its orbit actually takes it far beyond them at its most distant point. The dwarf planet is estimated to reach some 2,300 Astronomical Units (AU) from the sun at maximum, putting it more than twice as far out as Sedna. Earth is one AU from the sun, so the new object, at maximum, is 2,300 times further from the sun than we are.

2015 TG378’s nickname comes from the letters TG in its official name, as well as a recognition of the fact that it was found around Halloween, the authors say.


The orbits of the new extreme dwarf planet 2015 TG387 and its fellow Inner Oort Cloud objects 2012 VP113 and Sedna as compared with the rest of the Solar System. 2015 TG387 was nicknamed ‘The Goblin’ by the discoverers, as its provisional designation contains TG and the object was first seen near Halloween. 2015 TG387 has a larger semi-major axis than either 2012 VP113 or Sedna, which means it travels much further from the Sun at its most distant point in its orbit, which is around 2300 AU. Illustration by Roberto Molar Candanosa and Scott Sheppard, courtesy of Carnegie Institution for Science

The vast distances the object must travel to complete an orbit means that it only travels around the Sun once every 40,000 years. We were lucky we caught The Goblin when we did, says Sheppard, because it’s only visible to use with current technology less than one percent of the time.

And the find reinforces the idea that there are likely many more objects like it in our solar system orbiting out of sight.

“For over 99 percent of TG387’s orbit, it would be too faint for us to detect it,” Sheppard says. “This suggests we are only seeing the tip of the iceberg of these kinds of objects and that there are thousands of them that are too far away for us to see.”

Planetary Dance

As of right now, we only know of a handful of these so-called “Trans-Neptunian Objects,” those that live out beyond Neptune’s orbit. None so far have been designated planets, but at least two, Eris and Pluto, are quite large, with diameters of well over 1,000 miles. Most follow eccentric orbits that loop relatively near to the sun before taking them to the edge of the Kuiper Belt some 50 AU out and beyond. This makes them hard to find, but modern telescopes have begun to pick them out against the blackness of space.

The few that we do know of behave in a curious way, though. Though most orbit too far from the giant planets like Jupiter and Neptune to be influenced by their gravity, most distant objects seem to be moving in accordance with some powerful gravitational force in the outer solar system. This planetary harmony was first picked up on by Sheppard and collaborator Chad Trujillo in 2012, when they discovered 2012 VP113, but subsequent discoveries have only bolstered their theory.

In essence, their orbits are arranged in such a way that it seems like there’s another large planet tugging them into alignment. Called either “Planet X” or “Planet Nine,” this still-hypothetical world could remain undiscovered in much the same way The Goblin did.

Chasing More Goblins

Sheppard says that The Goblin’s orbit fits exactly into their models of how distant objects should behave if Planet X exists, further bolstering the notion that another massive world may be hiding in our solar system.

“When we put a hypothetical distant massive Planet X into our numerical simulations of the solar system, TG387 is still stable,” he says. “This is not true if you just randomly placed small objects into the outer solar system, as they would mostly be unstable to a massive Planet X.”

Sheppard hopes to find more objects like The Goblin to further pin down the location and orbit of the potential Planet Nine. The outer solar system is still a largely unknown place, and astronomers will likely be discovering new objects there for years to come.

“There are a lot of exotic and extreme objects yet to be found in the outer solar system,” he says. “We are only just now uncovering what the very outer solar system might look like and what might be out there.”
Including, perhaps, a true ninth planet.

Translated from Portuguese by Microsoft
☄️ Meteor ☄️ registered in Mexico City, Mexico 🇲🇽 on December 08! #meteoros #astronomia #citizenscience

Top 10 Most Astonishing Asteroids
Published on Jul 2, 2015
The top ten most interesting asteroids, with Scott Manley and Astrum! We're turning our attention to some of the smaller but nonetheless remarkably fascinating objects in our Solar System. You'll be amazed at how much there is to know and see about asteroids. List of asteroids mentioned:
10. 2005 VX3
9. 99942 Apophis
8. 25143 Itokawa
7. 2 Pallas
6. 10199 Chariklo
5. 21 Lutetia
4. 433 Eros
3. 243 Ida
2. 4 Vesta
1. 1 Ceres

Jose Maria Madiedo
Translated from Spanish by Microsoft
A rock from an asteroid enters the atmosphere at 86mil km/h and produces a brilliant fireball over Granada and Almería @ideal_granada @Almeria24h @lavozdealmeria @DiarioDAlmeria @ideal_almeria @ElHuffPost @miangulo_95
Translated from Spanish by Microsoft
This is the trajectory that has followed the fireball, which has been recorded at 3:51 in the morning @ideal_granada @Almeria24h @lavozdealmeria @DiarioDAlmeria @ideal_almeria @ElHuffPost @miangulo_95
Translated from Spanish by Microsoft
The event has been recorded by the detectors that the SMART project (@UniHuelva) has in the observatories of the Hita (Toledo), Calar Alto, Sierra Nevada, La Sagra and Sevilla @ideal_granada @Almeria24h @lavozdealmeria @DiarioDAlmeria @ideal_almeria @ElHuffPost @miangulo_95

Translated from German by Microsoft
The first interesting star cover in the new year: Double asteroid (90) Antiope covers an 11-mag star on January 4/5, 2019, the cover path crosses Doppel-Asteroid (90) Antiope bedeckt Stern am 4. Januar 2019 über Europa - Forum der Vereinigung der Sternfreunde … far south Germany

Call for Observation
(90) Antiope occults 10.8 mag star on 2019 January 04 in Europe
In the late evening of January 4th, the double minor planet (90) Antiope will occult TYC 1868-00281-1 (10.8 Vmag) for an expected duration of 8.4 sec. In Europe the centre line will cross Romania (~23:17 U.T.), Hungary, Austria and Germany (~23:18 U.T.) and France (~23:19 U.T.). In the case of an occultation by minor planet the combined magnitude will drop about 2.6 mag. The target area is located about 64deg above the horizon in the southwestern sky (for position at centre line at E 12deg).

Path maps for Europe
Centre line: Romania, Hungary, Austria
Centre line: Austria, Germany, France

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Today three new discovered asteroids at the beginning of January passed and are passing earth in a save distance. Unfortunately the Nasa site which lists them is not available at the moment.
  • 2019 AT6: January 15th, 3:20
  • 2019 AM8: January 15th, 16:03
  • 2019 AG7: January 15th, 22:43
Don't know how often that happens or happened, but three new discovered objects should be pretty rare or it will be the new normal.
Saw a comet where I live in Western Australia yesterday evening, fairly large and fairly slow moving. I came from roughly a western direction at an angle of 45 deg from the horizon. I was sitting on the verandan, in front of me is another house. Just before the comet disappeared behind the roofline of the house, it split in two fragments. the core was white, with a bluish-green centre. It was quite an aweinspiring phenomenon!

So far I haven’t found any account of it in the local or state news.
There's a definite upswing with an incoming of celestial bodies in progress!

A VISITOR FROM BEYOND THE KUIPER BELT: Comet Iwamoto (C/2018 Y1) is coming. On Feb. 12th and 13th, the dirty snowball will make a rare visit to the inner solar system, passing by our planet only 0.3 AU (45 million km) away. Here it is, approaching Earth on Feb. 7th from the constellation Virgo:


Amateur astronomer Michael Jäger made the 41-minute movie at his private observatory in Jauerling, Austria. At the time, Comet Iwamoto was crossing the celestial equator, so there are many streaks in the movie from geostationary satellites. (Update: A new movie from Jäger shows even more satellites including one satellite flare.)

Discovered in Dec. 2018 by Japanese amateur astronomer Masayuki Iwamoto, this comet is a visitor from beyond the Kuiper Belt. It comes from the realm of Extreme Trans-Neptunian Objects (ETNOs) more than 5 times as far from the sun as Pluto. This means it could be a relative of other ETNOS such as Sedna, 2012 VP113 ("Biden"), and 2015 TG387 ("Goblin").

Comet Iwamoto doesn't visit us very often. Following a highly elliptical 1371-year orbit, its last passage through the inner solar system was around 648 AD (unrecorded), and its next won't happen until 3390 AD. Therefore, if you want to see the comet, now is the time to look.


Above: Click to view an interactive 3D orbit of Comet Iwamoto, courtesy of NASA/JPL

Shining with an astronomical magnitude of +6.5, the comet is invisible to the unaided eye. Nevertheless, it will be an easy target for backyard telescopes in the nights ahead as it glides through the constellation Leo the Lion high in the midnight sky. If you have a GOTO telescope, use this ephemeris to point your optics--and submit your images here.


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