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Two other innocent asteroids shared by the sensationalist press. I get PMs of people really scared about it. These two asteroids are not only harmless, but they have never even been considered for the Sentry table. And no they are
no planet killers. They are not big enough to do more than have minor
overall effects like a few months of cooler weather because of the dust
l & # 39; atmosphere. Big enough to affect the returns of our
crops for a year. But it's an academic question because they can not hit.
To reject:
There was NO ASTEROID WARNING.
You can check this here with my non-technical interface to NASA's Sentry board here:
You should therefore strike out Business Insider and Daily Express from your list of reliable sources of asteroid information.
These stories are due to confusion, because they do not know what is meant by "potentially dangerous asteroid" or PHA.
They then summarize their ignorance in the pseudo-scientific discourse on asteroids that deviate in space due to the Yarkovsky effect and gravitational keyholes.
These are borrowed words, they are real effects, but these non-scientific journalists do not know how to use them; they do not apply here.
This is another article I write to support the people we help in the Doomsday Facebook group Debunked, who find us because they are scared, sometimes to the point of feeling suicidal, by such stories.
Share it with your friends if you find it useful because they may also panic.
What is an asteroid or a potentially dangerous comet (PHA)?
Short summaryit means that its orbit is at a certain distance from the Earth. This does not mean that it is a real danger. For example, 2010 TK7 (150 to 500 meters in diameter) permanently orbits a third of an orbit in front of the Earth. This is not a danger for us because we always have a third of orbit in front of us. However, as he constantly follows the same orbit as us, he gets this PHA classification.
There are many others that sometimes cross our orbit but still at great distances from the Earth. They are also PLHIV, but no threat to us.
Most of the time, they have a chance to touch us over the next few tens of millions of years, but they can not touch us yet.
If it's not in the Sentry table, it will not hit us in this century and probably not for many centuries.
Technical term: It simply means that an asteroid of more than 150 meters in diameter is located at a certain distance from Earth's orbit (0.05 instead of 7.48 million kilometers). For a comet, it must also have a maximum period of 200 years.
Whenever they close overflights of the Earth, it deflects them into slightly different orbits. It is really hard to hit the Earth because of its size, so it will usually end up being diverted to other orbits far from the Earth. The Earth is erasing its orbit over a period of tens of millions of years, most of them being sent elsewhere.
Most of them will eventually hit the sun after many overflights of several planets, or by Jupiter or being ejected from the solar system.
A few percent eventually reach other planets, including some that will eventually hit Earth, probably thousands or even millions of years into our future.
Most come from the original asteroid belt, and a few, less than one percent, come from beyond Jupiter after being deflected for the first time by Jupiter in short period comets of the Jupiter family.
Swift-Tuttle is the largest PHA known, with its 26 km width, which has a chance on an impact of 4479. It's plenty of time to divert it, no matter what technology we have in thousands of years.
The sensationalist press often publishes articles about PLHIV. If it's not in the sentinel's table, then it's not a risk.
You can search the object to see if it is in one of the other tables. For example.
Search for 1990MU
Search for 1998 OR2
Then click on the ESA page and they have it, the message "Not in the list of risks"
But if they do not have it (as in this case), you can click on the JPL page and they will usually have it. This is mainly to verify that you entered it correctly – if the name is correct and if it is not. In the Sentry table or the list of deleted objects, this has never been considered to pose any risk to the Earth.
The Wikipedia page is also often useful for asteroids:
What is a NEO?
Meanwhile, NEO simply designates an object whose perihelion (nearest point of the sun) is less than 1.3 ua, or 1.3 times the orbital radius of the Earth. Most are not even PHA.
According to one estimate, the largest undiscovered NEO would be about 3.5 km.
From Table 2-1. NEO population, frequency of impacts and expected completion of Update to determine if it is possible to improve research and characterization of NEOs. Numbers less than 1 are interpreted as a probability, for example 0.02 for objects 7.94 to 10.0 km in diameter. It's only 2% chance to find one or more objects of this size. Most of them will not be PLWHA.
The painting is complete from 10 km (size of the asteroid that ended the era of dinosaurs). There are only four asteroids and four comets of this size.
The asteroid 433 Eros (16.84 km) is the only other NEO of width 10 km or more that seems to have a chance to touch the Earth even in thousands of years.
This could affect us in a million years, with a 5% chance, but it is unlikely that it will hit us before 100,000 years ago.
Summary of the details of the eight objects: NEO asteroids and comets of 10 km or more.
How does the Sentry table work?
The Sentry table is automated. New objects automatically disappear as soon as they are identified as NEOs. The name corresponds to the year in which it was first observed, for example. 2007 then a code of two letters and a number. The first letter indicates the month and a half when it was found, for example: A is from January 1st to 15th, B is January 16th to 31st, and so on. So F is from the 16th to the 31st of March. Then the last bit, say, T3 in 2007 FT3, is awarded in a cycling system, the first asteroid of that half-month receives the letter A, and the letter until the 25 receives the letter Z (omitting the letter I), then it goes from A1 to Z1, and so on.
When they get the first observations, they often do not know whether it's an asteroid or not (maybe just a data problem). If so, he goes to the Scout table where he receives a temporary name. As soon as it is confirmed that it is a NEO, it is then transferred to the Sentry table if there is a risk, or only to the JPL tables and ESA. When an object is discovered for the first time, its orbit is not well known and there are many possible virtual orbits. Only one of them is the true orbit but it is not known at this stage. The impacts in the risk list relate to virtual orbits. When an object is removed from the table, it is usually because its orbit is better known and the virtual orbits that would impact can be excluded.
The smaller asteroids can change orbit over many years, even decades, due to minimal effects such as the absorption of sunlight and its re-emission as heat in a different direction when She turns. Comets can change slightly orbit due to outgassing and jets. But normally, the reason an object is deleted is simply because its orbit is better known.
This video explains how it works:
(click to watch on YouTube)
Asteroids can not sharply deviate from their orbit
The Yarkovsky effect is tiny and mainly concerns small objects, up to a few hundred meters in diameter. It can move objects in small quantities over the decades, but that adds up and if something happens very close to the Earth, it could make all the difference, so it's relevant to Bennu for example and Apophis. This is because sunlight heats a rapidly rotating asteroid, which then dissipates heat from the dark side when it turns away from sunlight. This minimal pressure of thermal radiation is sufficient to slightly change its position over the years and decades.
It's just silly to talk about turning a miss into a hit for an object that's millions of miles away and for big things like that.
Gravitational keyholes apply only to flyovers very close to the Earth, to the point where the next encounter with the Earth may depend on the precise location where they will fly over the earth gravity well.
Again, it's silly for an object that never approaches the Earth.
How to check
You can use my page to perform a unified search in the Sentry table, deleted objects, and then links to the JPL, ESA, and NEODys2 pages (I can add other pages if someone is familiar with them). other databases that I can access through the subject.
If it's not in the sentinel table or in the deleted items table, you know it's not a risk and has never been.
Table of Sentinels around NASA's Asteroids and Comets – Like words instead of technical numbers
Checking the distance to the JPL for dating is a natural thing to do but is not reliable as it does not show potential impacts.
for example. for 2007 FT3, because we only have 1 day of observation, this could be almost anywhere, giving a tiny chance of impact like throwing 9 or 10 dice and getting six each time .
2007 FT3
If you click on the JPL page, it does not even appear near approach in 2019 as it is probably the opposite side of the sun.
Still, it shows a flyby in 2068 with a lot of uncertainty, but not that much, since there is a very small chance that it will hit the Earth before that date.
The reason is that the distance of uncertainty that exists for the most likely overflight and does not include extremely unlikely events. That would be a number of standard deviations – I do not really know what, like e..g. could be 5% or 1% probability that it is outside this range.
If only the JPL page included a section on potential impacts, like the ESA page.
The ESA page does not say much, but indicates whether it is in the risk list or in the priority list or not.
Did you know?
If the Egyptians had built an asteroid-detecting telescope at the time of the Great Pyramid of Giza, more than 4,500 years ago, they would still be waiting for its first asteroid "city killer".
Combines a photo of the Khufu pyramid with one of the two ten-meter Keck telescopes. Related Hawaiian telescopes catch a new surprise (I know that the top of a pyramid in Egypt is not the best place for a telescope, it's just for a visual effect that shows the idea). In some respects, they were just a few key ideas of the industrial revolution. It's an alternative story not impossible :).
Many telescopes scan the sky every day to ensure your safety.
Some of the telescopes in search of asteroids every day
All asteroid tracking is done in the open air and it can not be hidden. It would be like trying to hide the news of a hurricane. Anyway, it is the work of the CNEOS, center of the minor planet, ATLAS, ADAM, main reason for which Pan STARRS warns us as soon as possible. Do not tell us after Congress and others around the world gave them hundreds of millions of dollars to warn us of asteroids, it would be like the weather forecast was saying, "All right, plan a day clear and sunny tomorrow "as a hurricane falls on us Miami. It just does not happen outside of the movies. They would have lost their jobs in a few minutes if they tried to do it and nobody would even want to do it.
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