Sadly, the catastrophic impact with Apophis asteroid isn't going to happen in 2068 Humanity can breathe a sigh of relief. Asteroid 99942 Apophis, a 340-meter-wide space rock scientists initially believed to be one of the most hazardous near-Earth objects, will not hit our planet in 2068 as feared, after all. “A 2068 impact is not in the realm of possibility anymore, and our calculations don’t show any impact …
A probe orbiting a body changes its orbit. It's a small effect, certainly. For small asteroids the change might notable after enough time has passed. I'm trying to say that it should be calculated precisely how the probe will change the location of Apophis in centuries so that the orbiting probe doesn't make a collision with Earth more likely...
Okay, I certainly don't know any specifics but an orbiting probe is one of the means a hazardous small body could be directed not to hit Earth, given we have enough time to do that. Just be sure that you don't make the situation worse.
"it should be calculated precisely how the probe will change the location of Apophis in centuries so that the orbiting probe doesn't make a collision with Earth more likely..."
Bananas should be avoided because they're both a yellow and white food.
Gimme your reasons, dammit!
An orbiting probe shouldn't have any impact on the asteroid's trajectory. Because the direction of the probe's gravitational influence will cancel out over all directions, over the course of multiple orbits. There will be some small perturbation due to the probe's initial encounter with the asteroid and the momentum the probe will give to the asteroid as it approaches, but that's it. Granted, you've got astronomical timescales on your side for any perturbation to influence.
Probes used as space tugs wouldn't orbit the thing they are tugging for the same reasons. They would have to continually manoeuvre to stay in the right place to provide the tug.
A satellite orbiting a body effectively increases the mass of the body if you treat the two bodies as a single one. This will affect the heliocentric orbit of the body. If the moon vanished from earths orbit, earth's heliocentric orbit would alter.
For the small relative mass of a probe for this little asteroid, the effect is going to be 10E-alot. So it would take some distance epoch to be anything but negligible
Somebody do it in STK. Or GMAT. Or could Kerbal do it?
I think the challenge is not the distance, but the speed. A probe mush match the speed of the asteroid, which at that point may be travelling faster than our current rockets are able to accelerate the probe. The asteroid missions performed so far (like Dawn, Osiris-Rex and Hayabusa) have first travelled in space for years before the encounter, picking up speed with ion engines or by gravity assists.
It might be doable, but here we really need an answer from an actual rocket scientist.
A small array of high speed cameras could capture it as it flies by, whatever its speed is.
To take a sample, you'll need to start moving soon to be able to match speed. Apparently, the Chinese plan to shadow it and maybe sample it.
https://en.wikipedia.org/wiki/99942_Apophis
The solar system has been rolling around for about 4.5 billion years now so the earth's orbit has pretty much cleared out all of the rubble - we've already been hit. All this means is the the chances of another big strike are low, but we have a few meteorites rolling around every year - so it might happen, but it might not.
Version 1.0 : "the chances of another big strike are low"
I think what you meant is that the chances of another big strike in the next few 100 years is pretty low.
"Astronomers estimate there are hundreds of thousands of objects in the Kuiper Belt region that are at least 60 miles- (100 kilometers-) wide or larger."
(From https://solarsystem.nasa.gov/news/792/10-things-to-know-about-the-kuiper-belt/ )
I suspect that the chances of another big strike on Earth are pretty much 100%, over the next 100 million years, all we need is for something to perturb the Kuiper belt or Oort Cloud ever so slightly...
Why do those darn scientists have to cross my profitable plan of selling asteroid shelters? Truth and realism is not a good way to make money.
Please, dear scientists, let us save the fear and doubt to make the extra buck. Please tell the general public that there still is a real change that you are wrong and the world will end by extraterrestrial impact. I'm even willing to share a very small percentage of the asteroid shelter winnings so we'll all have a comfortable future.
No problem.
Just deploy an impactor that will change Apophis's vector by just some single digit m/s by 2025.
Least impact energy will be needed near Aphelion.
Over the following 4 years this minimal correction will deliver the needed delta-V to hit a target of your choosing in 2029...
If you need more time to ramp up sales, change the target time to a different close fly-by further in the future.
Urrrr.... you really don't want that to happen....
Asteroids like that ( by current estimates) aren't solid rock, but rather an aggregate clump. If it hits a satellite at the speed it is going the result will not be pretty. At all....
A direct impact by the asteroid would be significant, but not "world-ending" , despite the Doomsayers. But at least it'd hit in one spot. What would happen after a collision is anyone's guess, but the next pass of the remains would make for Interesting Times.
Rubble pile or solid, at 340 meters Apophis would damage a fairly big spot.
Meteor crater in Arizona, USA was estimated to be in around 30-50 meters wide. It made a crater 1200 m wide and 170 m deep. A really big hole. The impact energy has been estimated at about 10 megatons TNT. So the wind and heat blast would have damaged a bigger area then just the crater.
Bigger estimate for Meteor crater blast energy said the safe distance to watch it hit might be 40 miles away.
https://astronomy.com/magazine/ask-astro/2015/04/blast-radius
So Apophis is 6-7 time more volume. You would want to no be too close to the "spot" it came down at.
"Meteor crater in Arizona, USA was estimated to be in around 30-50 meters wide. It made a crater 1200 m wide and 170 m deep. A really big hole. The impact energy has been estimated at about 10 megatons TNT. So the wind and heat blast would have damaged a bigger area then just the crater."
Wasn't that based on the assumption it was a single big boulder of nickel-iron while this one is apparently an aggregation of rocks? Would that make much of a difference?
Not at impact. A loose aggregation would shed material as it came down but once it hits the earth at several tens of Km/s its basically a ball of plasma whatever it was a fraction of a second earlier and this is what makes the hole. A metal meteor can sometimes retain lumps that burrow further into the earth under the crater so an aggregation of rock actually puts more energy into the crater digging and scorched earth thing.
some satellites in geosynchronous orbits
To be in a geosynchronous orbit a satellite must be 22,236 miles up, if not it will not stay in the same apparent place above the earth. So how can it be closer than some and not others ?
Only after all the rich people have already left/hidden in the shelters.
Of course they'd forgotton just how much work us minions do to keep them in luxury and stupidity of leaving us all to die.
"Erm... does anyone know howto open a tincan? what about you?"
"I cant dear... it might break my nails and you know how much is costs to have them redone... how are you coming along with that fire?"
try "When Worlds Collide". 1951 movie:
https://en.wikipedia.org/wiki/When_Worlds_Collide_(1951_film)
"Pilot David Randall flies top-secret photographs from South African astronomer Dr. Emery Bronson to Dr. Cole Hendron in the United States. Hendron, with the assistance of his daughter Joyce, confirms their worst fears: Bronson has discovered that a rogue star named Bellus is on a collision course with Earth.
Hendron warns the United Nations that the end of the world is little more than eight months away. He pleads for the construction of "arks" to transport a lucky few to Zyra, the sole planet orbiting Bellus, in the faint hope that the human race can be saved from extinction. Other scientists scoff at his claims, and his proposal is rejected by the delegates."
Some squillionaires have bought farms etc. in supposedly 'safe' countries (New Zealand, I am looking at you). One academic who studies survival and societies was at an expensive seminar / group conference for these 'dudes' and was not asked things like 'what skill set do I need to recruit for maximum chances of survival / to rebuild society quickly after the apocalypse?' but "How do I control my guard force so they don't take over?"
Just think about how many highly skilled professions you use every year just surviving and you'll see the pointlessness of spending your wealth preparing for the apocalypse compared to preventing it:
dentists
doctors: GP, oncologist, epidemiologist, physiotherapist, psychiatrist, cardiac / thoracic / dermatologist
plumber / gas fitter / electrician
IT specialists (Reg members, I am not going to enumerate you, lets just say 50 different skills shall we?)
Mechanical engineers (car mechanics etc.)
Structural engineers (bridge, house, etc. construction)
Power engineers (electricity substations, power lines, generators, hydroelectric generation etc.)
Chemists: water treatment, cleaning chemicals, soap manufacturers etc.
Horticulturalists; Farmers, plant disease specialists.
Veterinary scientists (animal care, treatment, slaughter procedures)
Paper manufacturers, ink, pen pencil paint manufacture.
Writers (people who write coherent manuals are actually quite useful)
And many many more
Risk? Surely likelihood.
The word risk is so widely used (even by scientists and risk professionals) to indicate probability alone, consequence alone or the product of both (sometimes even within the same document) that it's effectively ceased to be usable safely as a technical term.
With this year's current record Apophis will probably ( despite the improbably huge nature of space) hit some piece of old space junk which will send it into an inescapable death dive towards Earth which it will hit on December 25th, striking the site a large nuclear waste/weapons dump with uncanny accuracy and just outside the blast radius causing an armoured van filled with an unlawfully developed weaponised new Covid/Flu/Ebola/ variant to crash and burst open next to a crowded area filled with people waiting to go to the airport on holiday all around the world.
I'm just saying, don't buy a lottery ticket yet.
I reckon the worst place to hit would be pretty close to the South Pole. If it forced the Antarctic ice sheets into the sea there would be a pretty immediate global sea level rise of about 70m (seventy metres). The tsunami in the southern hemisphere (due to the rotation of the Earth) would devastate all east facing seaboards. Every major coastal city (2/3 of the world's major cities are coastal) would be inundated. There would be tremendous volcanic activity due to the increased weight on the tectonic plates (a mere 10cm extra snow creates a measurable increase in southern hemisphere volcanism). The rate of revolution of the world would slow, and I would have to move house as I live at a mere 50m above mean sea level.
“If we had binoculars as powerful as this radar, we would be able to sit in Los Angeles and read a dinner menu at a restaurant in New York,”
Haha! So the Earth is flat confessed that guy from the JPL! If Earth was a sphere, he wouldn't be able to read that menu in NY from LA!
Random: if the Alvarez object had missed, the dinosaurs might have eventually after smaller mass extinctions evolved into something a lot like us,
with binocular vision and bipedal locomotion.
The tail might have been retained but as with hominidae it got absorbed much like the appendix.
In fact its said that there might have been more than one intelligent species here on Earth, as mammals may have slowly expanded
to fill niches left by larger predatory saurians as the latter died off.
Cold blooded is actually not entirely accurate as some dinosaur fossils show evidence of a trend towards higher body temperatures
so something able to live in the savannah isn't completely ridiculous.
Feel free to downvote this back to the Cambrian Era.
"Cold blooded is actually not entirely accurate as some dinosaur fossils show evidence of a trend towards higher body temperatures"
I saw a program with David Attenborough. There was evidence that the larger dinosaurs were so big that there was no way they could warm up and then cool down on a 24 hour basis (yes I know day lengths have changed since the cretaceous, but not by too much). So they must have been warm bodied, if not necessarily warm-blooded. The Specific Latent heat of a brachiosaurus is probably quite high. Even something as 'small' as a T Rex would have had a hard time cooling down at night and then warming up again in the morning. Whether they were able to control their body temperatures by generating heat without digestion is another matter.
The binocular vision can be useful. I have both the 8X56 and 10X56 FL Zeiss models https://theoptics.org/best-binoculars-under-500/ , I also have the SLC 10X56. IMHO the FL handles glare and ghosting better than the SLC. The FLs were made to a standard that does not seem to exist today. For the night sky the SLC is not as soft as the FL near the field stop, but it is still soft. Neither show clear crisp stars near the field stop like like the SV in 10 or 12X50, but both show more on the night sky than the SV 10X50.
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