The Sentry Program, Near Earth Object Monitoring
An asteroid could easily wipe out all humanity, luckily NASA monitors them.
The Risk of Near Earth Objects
Near Earth objects continually put the planet at risk. There are a massive amount of them in space, over 15,000 being discovered so far. That means it’s only a matter of time until one heads in our direction. We must be ready or face the consequences. [1]
Although, the consequences are based on the size of the asteroid. Anything smaller than about 25 meters can be completely ignored, it will just burn up in our atmosphere. As an asteroid gets larger, about 150 meters, it hits the ground with more energy than the largest atomic bomb in history. Once it hits 300 meters an asteroid can impact the ground with an energy over 20 times that of the largest nuclear weapon. Once it gets a kilometer wide it could impact with almost 1000 times that same weapon, which is enough to eradicate an entire (smaller) country or cause a tsunami 32 meters high from as far away as 300 kilometers. An impact with an asteroid 10 kilometers wide would be he enough to cause 100 meter high tsunamis as far as 10,000 kilometers away. You can image what would happen to that continent.[2] [3]
Luckily events like this do not happen very often. On average a 150 meter asteroid strikes Earth every 16 thousand years. Or 300 meter asteroids it happens every 72 thousand years. Asteroids the size of one kilometer happen only once every 440 thousand years on average. [2]
You may think this gives us some breathing room, but not really. The real problem here is that we don’t actually know where all the Near Earth Objects are.
How The Sentry Pages Work
The sentry pages are split up into two main pages, the impact risk page and the main sentry page.
This page tracks the impact risk of NEOs. As new asteroids are discovered some will be put onto this page, because we don’t know where they will end up. After more observations and calculations are made asteroids are often taken off of this list. This category also does host a few “permanent resident” that have a very low but still non-zero chance of impact in the future.
This is often used as a reference source for scientists or the media. The calculations are complex and long, meaning there is large opportunity for error. This gives them a way to cross-check their work.
You can find the page here
The main sentry page is a collection of all objects that ever made it onto the impact risk page. All of the objects on this page pose basically zero risk and it is only used as a reference source.
Both of these pages use two different scales to measure the risk posed. One is the Torino Scale and the other is the Palermo Scale.
This scale is used mostly for communicating with the public. It takes into account how likely an impact is and how large the effect will be, but not the time until impact.
The scale ranges from 0-10. Most NEO are placed at zero, meaning that they either have a near zero chance of impacting Earth or will burn up in the atmosphere with no effect. Three is a close encounter with an object warranting an extra look by astronomers, this is usually reassessed back to zero. At six the NEO poses a major global threat, but it is still unknown if it will hit Earth and more assessment is needed. You can guess what ten means, a certain global catastrophe. Luckily this only happens once every 100,000 years.
You can see the scale here
The Palermo scale is more important to scientists. It compares the chance of impact with the chance of a random impact of the same size range. This is called relative risk. This scale is log base 10. Zero is equal to the average chance of the event occurring, a one on the scale means it is ten times more likely, a two means it is one hundred times more likely, and a negative one means that asteroid has 10% the chance of impacting as a random event in the same time period. [4]
This information is important to know, in the off chance that there is an emergency. Countries already have major problems working together, what do you think would happen if you added mass panic and a misunderstanding of the danger onto that.
Great post! We need many more of these to get people interested and engaged in the subject that is, after all, quite serious.
Working at ESA myself I was a bit disappointed to see that the ESA AIM project - short for Asteroid Impact Mission - did not receive the neccessary funding to proceed. Working in the same corridor as those responsible for the project logistics and strategy I am lucky to learn about it on a regular basis.
Hopefully it can still become the successor to ExoMars 2020 once other projects that have been prioritized are out of the way.
Anyways, I hope to share much more on this topic for those that are interested. Having just yesterday posted my introduction to steemit I look forward to doing many more blog posts about Asteroids, and the work that space agencies and private companies are doing in the field.
Asteroid research have always been on the top of my interest as I got into space in the first place chasing my curiosity to understand the origins of life. Since Asteroids carry the fundamental building blocks of our solar system in their purest form since its formation ~5 billion years ago they offer so much opportunity for us to learn from!
Anyways just wanted to give you a upvote and say that I look forward to discuss the topic a lot more and share both my own views and what I see working with the space community in general :)
Yeah space is interesting, too bad we are too busy funding war to fund space.
well I guess that's the highest stage of capitalism for you.
Indeed. It is quite frustrating to watch... Anyways perhaps this is where Blockchain can help have an impact. I can see a future where people are collectively funding and building new capabilities in space.
I think cryptocurrency might be better, but I still don't think its the solution. Still too much power given to the rich. Five people own half the wealth of the world, they could easily take over any blockchain.
Well, everything begins small. The accelerating inequalities have to a large extent been enabled by a time where a few handful of people have been able to serve the needs of many in a globalised economy. Especially on the web, what used to take hundreds of thousands of employees can now be done by a few software engineers.
However, I think we're slowly getting to the point where people are taking a pause, looking at the data, and wondering why they should continue to provide the essential foundation for a few people to succeed. I at least hope (although I'm far from convinced) that more people will start demanding that when some companies can profit absurdly from them giving up their 2 most important 21st century assets: Their time and their personal data, that they will also want a fair share of profit that is generated from them investing time in building content on the web, and them providing data that is vital for digital products to function.
This is where I hope blockchain technologies, and sites like steemit, can have an impact. No it won't solve the problems overnight. But it can help steer the balance a bit more in the right direction.
I think at this point they have enough power to prevent any small shifts in power, they have been happening for hundreds of years. At this point only a full scale revolution can solve our problems.
Capitalism will always form monopolies and in the end stages always be controlled by a few.
Good post, it is important to be informed of the different versions, that people have about these phenomena, although God is in control.
get off my profile
If God is in control he seems rather inept considering the almost endless misery visited upon so many who have done nothing but be born in a part of the world without access to modern-day medicine.
I don't want to know the God that allows suffering on such a scale to go on if he is "in control". If any human being had the control you assign to your god, yet allowed the state of the world to be as it is, we would rightly call them a monster.
I realize that by following you I will know a lot about space. :) So glad I came across your introduction! Keep the good work up. :)
Quite scary!! Even if the Nasa monitors them...
Nothing helps put life into perspective like the constant potential for a single large rock to wipe out you entire species.
yeah that about sums it up, well except for the fact that there are a lot of other ways it could happen too ;)
i just followed and Happy 4th of July!