89

Impacting solar system objects would have relative closing speeds from around 11 to 72 km/s. We could take the optimal case that the asteroid approaches whilst fully lit by the Sun (which I think precludes the minimum and maximum speed in the range quoted above) and then scale from another similar body - say the asteroid Vesta. This has a diameter of around ...


38

The name used for such objects is vulcanoids. This term refers to the hypothetical intra-Mercurian planet Vulcan, which was proposed by Urbain Le Verrier (best known for his successful prediction of the existence of Neptune) to account for the anomalous precession of Mercury's orbit that is now explained by general relativity. Note that the expected number ...


19

Yes and here's a video of "a Giant Comet Hitting the Sun": https://www.youtube.com/watch?v=Mat4dWpszoQ The impact occurred sometime during May 10-11, 2011. The comet was not named but believed to be a member of the Kreutz family of comets Many close calls Before this spectacular plunge we had witnessed several other comets graze (come close without ...


19

Of course you would need to specify who the person is - an Olympic athlete? Let us assume so and then you can scale downwards accordingly. So an Olympic high jumper can jump hard enough to raise their centre of gravity about 2m off the ground. Let us assume this is a ballistic problem. The athlete actually gives themselves sufficient upward speed to get ...


17

I'm pretty sure that the radial pattern found in the data is a result of WISE's approximately 90 minute sampling cadence (dictated by the satellite's orbit), astrometric precision (about 0.2 arcseconds in the stacked images around launch, see Wright et al. 2010), and the number of free parameters in fitting the asteroid orbits based on that data. See, in the ...


16

Well, that article was never accepted for publication in any peer-review journal apparently. That said, estimates may vary widely depending on assumptions about the composition and velocity of the asteorid. One could estimate the mass of the object assuming compositional ratios similar to a certain class of objects and integrating the whole Iridium deposits ...


15

We actually have a very good idea of this because the Mars Reconnaissance Orbiter has been orbiting Mars for over a decade. The MRO is, basically, a spy satellite around Mars and is continually taking high-resolution photos of the surface. It has revisted much of the surface, taking pictures multiple times over the years. As a consequence, we have a very ...


14

The Yarkovsky effect is the thrust on a small object in space that has been heated by sunlight, created from radiant energy. The YORP effect is when the thrust produces rotation, likely due to uneven heating or differences in surface projections (IE: A mountain acts as a better solar collector than a flatter portion of a spherical object on the opposite side)...


13

The strength of the Earth's gravitational field compared to the Moon and the Sun is not enough to capture and hold satellites - there are too many disruptive forces that would rip them away over time. However there are some objects at the Lagrangian points - the points where the gravitational fields of the Earth and other objects are equal and so it is ...


13

You are right that the tilt of the asteroids are distributed in very random way, and that the rotation of the Solar nebula is a minor contributor to that tilt, and only skews it a little. However, you are not right that randomness simply adds up. The randomness does in fact cancel out more and more when you combine a large amount of asteroids, until the ...


13

I also googled "iridium content of comets", and the first result was https://news.dartmouth.edu/news/2013/04/dartmouth-researchers-say-comet-killed-dinosaurs Now there is currently no consensus on the nature of the Chicxulub impactor. The observations of iridium and osmium suggest an asteroid. A minority opinion is that a comet may be responsible. The ...


13

The time of the orbit is not well known but the inclination can't change as much (small changes in velocity due to outgassing can significantly change the orbital period, but can't change the inclination much. So, while we have a good idea of it's orbital track close to perihelion, we just don't know when it will be there. We don't know where the Earth will ...


12

Many models shown in books or television show a very populated asteroid belt but in fact the belt is mostly empty. To answer your question, the inclination of the asteroids vary a lot going from 0° to 40° although most off them are in between 0° and 30°; See The orbital element distributions of real and modelled asteroids. So yes it would be 3 dimensional.


12

The computer program you are asking for is literally impossible: Even ignoring the affect of the greater universe and transient visitors such as comets on hyperbolic orbits, the Solar system is a chaotic complex system. We have a pretty good handle on the motion of the bodies we are, and have been aware of, during the time modern astronomy has been ...


12

Yes, there are, but they are very rare. Wikipedia has a list of retrograde asteroids, and mentions: As of September 2016, of the more than 700,000 minor planets known, there are only 95 known retrograde minor planets. That means only 0.014% of known minor planets are in a retrograde orbit. The asteroid with the highest known inclination is 2013 LA2, ...


12

It would be much better for Earth if the impactor hit the moon... In this Worldbuilding answer, I used a paper on ejecta kinematics to do calculations for ejecta velocity upon impact. Without going into too much detail here, much of the ejecta from a large impactor would not exceed the moon's escape velocity of 2.38 km/s. You can examine Figure 7 from the ...


11

There is definitely not a catalogue of all meteorites hitting Earth. For instance, the ones falling in desert areas and in the ocean aren't found, and even the ones falling in more populous regions are easily mistaken for normal rocks. Meteorite rate Meteorites come in all sizes, from sand grains to dinosaur-annihilating rocks. The size distribution of ...


11

There is no chance of a collision in the short term. 2020 CD3 is in a rather chaotic orbit of the Earth that extends well beyond the moon and doesn't come very close to Earth Each orbit is different, but no orbit brings it closer than the moon. The orbit is irregular because it is perturbed both by the moon and by the gravity of the sun. At its furthest ...


10

The objects you are refering to are actually two different objects: asteroids and comets. Meteor and meteorite are other names for an asteroid, at a given time of its interaction with our planet. We'll get to that. So first, what is the difference between an asteroid and a comet? A comet is a small solar system body that display a "coma" (an atmosphere of ...


10

Was it Comet Hale-Bopp? It was discovered in 1995, but made a very close approach in 1997, earning it the nickname "The Great Comet of 1997". Wikipedia states As it passed perihelion on April 1, 1997 the comet developed into a spectacular sight. It shone brighter than any star in the sky except Sirius, and its dust tail stretched 40–45 degrees across the ...


10

Wordy answer, mostly light on Math: The key word here (and the article uses this word) is "long period comets". First there's Jupiter impacts, but that's a relatively low percentage, cause even large Jupiter is quite small compared to it's orbit. Even if you extend it out to it's Roche limit where a comet could break apart, it's still a very small ...


10

A carbonaceous condrite has the same reflectivity as the moon at around 7-13%. If there was ice, if the tail was 10 times smaller than hail bopp, it would have auspiciously covered half of the sky. it could have made an incredible display in the 1-2 days preceding the collision, because it was as close to the sun as hale bopp, the brightest astronomical ...


9

TL;DR version: Too big and way, way too late. The dispersal can't be done, even at the lower end of that 3-20 km scale. Holsapple claims 5 kilojoule/kg are needed to disrupt and disperse a solid 1 km asteroid asteroid, with energy scaling with radius1.65. Disrupting and dispersing a solid 3 km diameter asteroid with a density of 3 g/cc would require a ...


9

A lot of the naming conventions were originally "because they remind us of things we already called this", or simply "tradition". How we name things has slowly but surely adjusted with time as more objects were found, and a more robust classification system was needed. Imagine it like having bins to sort your toys into. If you have a small number of balls,...


9

Answer based on a misunderstanding of the question, left here because it contains some useful background on WISE. The pie-shaped patterns starting in 2010 are results of the WISE mission (see the video description). The radial pattern within those pie shapes is not explained by my answer. NASA's Wide-field Infrared Survey Explorer (WISE) is a space ...


9

If this is something that you have found (rather than purchased as a meteorite) the chances are very small that it is a meteorite. Even if it is a meteorite, the chances it's a Martian one are even smaller still and none have been found in the United States. According to the Meteorites in the US page, which draws from the Meteoritical Society database, only ...


9

It is important to appreciate the scale of the comet's orbit compared to the Earth's orbit. The Earth goes round the Sun in a nearly circular path. The average distance is one Astronomical Unit (AU). C/2020 F3 (Neowise) has an incredibly skinny elliptical orbit. It's closest approach to the Sun (perihelion) is at 0.3 AU, which is inside the orbit of Mercury. ...


8

A comet is usually characterized by its tail. A dead comet has lost all its ices and gases (responsible for producing this tail), leaving just a rocky core. The Halloween comet is such a dead comet, in that it has no tail, but furthermore it resembles a skull, making it particularly relevant for Halloween.


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