Boffins find asteroid with the shortest solar year of any space rock in our Solar System The newly discovered kilometre-sized asteroid dubbed 2019 LF6 has the shortest solar year around our Sun – compared to all the other space rocks found floating around the Solar System at just 151 days. 2019 LF6 belongs to a small group of space rocks classified as “Atira” asteroids, which orbit between the Earth and the Sun. …
Could it be the case that instead of having two general belts of asteroids (as defined on School astronomy charts), that the areas cleared by planets are actually the exception and there's just a general abundance of asteroids all around the solar system except for where planets have cleared a path?
Cool find though.
I think if you run the rather chaotic many body maths you will find that there are only a few attractors in the solar system and orbits that lie outside of these are unstable
I would be willing to bet that this particular asteroid will only last a few thousand or even million years in its current approximate orbit, before being perturbed [again?] by a close brush with Mercury or Venus
After a quick search, I learned that Atira asteroids are "confined to a zone inferior to Earth orbit".
So that is why they can be so quick around the Sun. Also, I guess we have nothing to fear from them as long as they stay where they are.
On the other hand, if something jolts them out of their orbit, it won't take long to become a very serious threat.
After a quick search, I learned that Atira asteroids are "confined to a zone inferior to Earth orbit".
Or you could have read the article?
On the other hand, if something jolts them out of their orbit, it won't take long to become a very serious threat.
If they're inside Earth's orbit then whatever "jolts" them would have to speed them up to give them the energy to get any nearer to us. I'd be more worried about objects with orbits which either cross or are outside our own.
"If they're inside Earth's orbit then whatever "jolts" them would have to speed them up to give them the energy to get any nearer to us."
Which is far from impossible, but for an object to get a gravity assist which managed to put it on a collision course with the Earth would be pretty unlucky. (Of course, any objects on a collision course with Earth, are by definition, unlucky.)
Generally though, we worry about stuff from outside our orbit (which would require a similar amount of energy to 'jolt' their orbits down to intersect the Earth), but that's mainly because there's more stuff outside our orbit, than there is inside it.
If they're inside Earth's orbit then whatever "jolts" them would have to speed them up to give them the energy to get any nearer to us.
Also, since this one, at any rate, has an orbit highly inclined to the plane of the ecliptic, whatever gives them the boost the increase their orbit (by a significant fraction of an AU) would also have to happen in exactly the right way to neatly pop it back into the ecliptic.
I reckon the probability of an interaction (probably with the same planet that knocked them out of the ecliptic in the first place) that boosts their kinetic energy enough, alters the plane of their orbit, and pushes them into a new orbit that crosses that of the Earth is so vanishingly small, it may as well be zero. I know million-to-one chances happen nine times out of ten, but the sorts of odds involved are going to make million-to-one chances look like a certainty.
The 20-30 min window twice a day isn't very long, Is it time we considered building an observatory on Mercury where it can look out into a well lit inner solar system without the Sun getting in the way? I know there's a thin exosphere but that shouldn't be much of an issue when looking for rocks big enough to worry about.
The most expensive part of building a base on Mercury will be shipping the blankets and sunscreen. It's not tidally locked to the sun, but its day is longer than its year, so your surface installation will either be in a deep freeze (practically no atmosphere to trap heat, or distort telescope pictures), or in blistering heat and super high solar flux.
But at least you could power the whole base with a solar cell from a pocket calculator......
Mine's the one with the SPF 9001 in the pocket.
This is a solved problem bar minor technicalities: your observatory hovers in shadow by the Sun-Mercury L2 point, hanging from an annular sail. The thrust from the mirror stabilises the orbit, directs sunlight onto the cold cells powering the satellite, and the instruments look through the hole!
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