What is Asteroid: Definition and 281 Discussions

An asteroid is a minor planet of the inner Solar System. Historically, these terms have been applied to any astronomical object orbiting the Sun that did not resolve into a disc in a telescope and was not observed to have characteristics of an active comet such as a tail. As minor planets in the outer Solar System were discovered that were found to have volatile-rich surfaces similar to comets, these came to be distinguished from the objects found in the main asteroid belt. The term "asteroid" refers to the minor planets of the inner Solar System, including those co-orbital with Jupiter. Larger asteroids are often called planetoids.

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  1. Astronuc

    B Asteroid 2024 BX1 entered Earth's atmosphere over Germany 21 Jan 2024

    Asteroid 2024 BX1 that exploded over Berlin was fastest-spinning space rock ever recorded https://www.livescience.com/space/asteroids/asteroid-that-exploded-over-berlin-was-fastest-spinning-space-rock-ever-recorded Visualisation of the trajectory and impact of asteroid 2024 BX1 on 21 January...
  2. Z

    I An asteroid the size of the Rose Bowl has a slight chance of impacting Earth?

    I have heard that an asteroid the size of the Rose Bowl has a slight chance of impacting Earth. Experts say you should not "blow it up" because then we would have many smaller impactors with random trajectories rather than one big one that we could pinpoint with accuracy. But, Wouldn't many of...
  3. BWV

    B Uracil found in carbonaceous asteroid

    Extraterrestrial origin of a sample of Uracil, one of the four bases of RNA. Would imply biochemistry and therefore life is common across the universe, just needing an environment in which to evolve: Abstract: The pristine sample from the near-Earth carbonaceous asteroid (162173) Ryugu...
  4. ananonanunes

    Average distance between asteroids in the asteroid belt

    What I did was find the total area of the space between the Kirkwood gaps and the area occupied by the asteroids (assuming they all had a 100m radius). I subtracted the two to get the area that is empty in that region. To find the average empty area between asteroids I divided this by the...
  5. pinball1970

    Stargazing Asteroid filmed over the English Channel

    Quite rare to get one on film so worthy of a thread on its own,"It is just the seventh time an asteroid impact has been predicted in advance. The European Space Agency tweeted that it was "a sign of the rapid advancements in global asteroid detection...
  6. Tom4

    How Does an Asteroid's Speed Change Upon Impact with Mars?

    Since the radius is "very far", I cannot find the total mechanical energy by using the gravitational potential energy formula and find the kinetic energy at impact. I can't think of any other way to find final velocity without knowing the radius.
  7. O

    NASA's DART spaceship has hit the Dimorphos asteroid: what now?

    NASA's appropriately named "DART" space mission (for "Double Asteroid Redirection Test"), funded at some 330,000,000 worth of USA taxpayers' dollars, has been, as far as we know at these still early days, successful in its various planned goals: to navigate to the asteroid Dimorphos, then hit it...
  8. tech99

    Stargazing Why does the asteroid Dimorphos leave a trail after impact?

    Pictures have appeared showing the asteroid Dimorphos following its impact with a spacecraft and showing a trail being left behind. On further consideration, this is taking place in a vacuum, so there is no air resistance. Why is the debris forming a trail behind the asteroid?
  9. S

    I Gas Density of Lunar Crater Rims: Comet vs. Asteroid Impacts

    I mean - when they form. What are typical gas densities at lunar crater rim when the crater is made by a comet? An asteroid? Both a comet and an asteroid, hitting Moon at several km/s, initially heat up to several thousand K, and even asteroid produces some vapour... at hypocentre. However, by...
  10. BWV

    When you say asteroid mining, people laugh at you

    Too bad they are late to the SPAC party, could have raised billions Dont see how it will ever be more economical to bring minerals down from space rather than just dig deeper for them on Earth
  11. Isopod

    Dinosaur killed in asteroid strike found

    Scientists have presented a stunningly preserved leg of a dinosaur. The limb, complete with skin, is just one of a series of remarkable finds emerging from the Tanis fossil site in the US State of North Dakota. But it's not just their exquisite condition that's turning heads - it's what these...
  12. S

    Conservation of momentum of spacecraft and asteroid

    By "DART will have a relative speed of 6250 ms-1 when it collides with the asteroid", I assume it is the relative speed of the DART with respect to the asteroid. Using that assumption, I can answer question (a) For question (b), I don't understand the solution from the teacher. He did it like...
  13. A

    I Radioactive Dating of Asteroid Elements: How Do Scientists Know?

    When scientists use radioactive dating of elements in the asteroids to determine the age of the solar system, how do they know what the original amount of the radioactive element that was in the rock was? Do they need to know what the original amount of the radioactive element was in the rock...
  14. Rendering

    Impact events: when were they first seen as potentially catastrophic?

    (This is a history of science question, so please let me know if it's not appropriate to this forum.) When did someone first realize that major Earth impact events (asteroids, etc.) could potentially be catastrophic? To be clear, I don't mean in the purely theoretical sense (the likely given...
  15. F

    I How to change CSpice initial velocity from an Asteroid SPK file?

    Hello, I've made a SPK file for asteroid 7482 (1994 PC1) with Horizon. I wan't to change the initial velocity with cspice, because I want to know where it will be in a future time at the speed changed. (now I'm using Newtons calc but is slow an error increases with time). This is for calculating...
  16. berkeman

    DART mission launches to test asteroid deflection

    Um, why are we spending $330M on a mission to (re-)prove that conservation of momentum works in space? What am I missing? https://www.cnbc.com/2021/11/23/spacex-launching-nasa-dart- spacecraft -to-crash-into-an-asteroid.html SpaceX is launching a NASA spacecraft that will crash into an asteroid
  17. Jarvis323

    Most realistic asteroid impact/end of the world movie yet?

    Is this how people would react to a looming world ending asteroid impact?
  18. Anmoldeep

    Expanding explosion from an Asteroid

    An asteroid of mass M explodes into a spherical homogenous cloud in free space. Due to energy received by the explosion, the cloud expands and the expansion is spherically symmetric. At an instant, when the radius of the cloud is R, all of its particles on the surface are observed receding...
  19. C

    Maximum safe mass of an asteroid in geostationary orbit

    Summary:: What is the maximum safe mass of an asteroid in geostationary orbit before it causes problems? Hello everyone, If there was an asteroid in geostationary orbit around the Earth, over the Pacific Ocean, what would be the highest mass it could have before it would start having...
  20. S

    MATLAB Calculating the time taken for an asteroid mission using MATLAB

    Using MATLAB, I am trying to calculate the time taken for a spacecraft to travel from Earth to a near Earth asteroid and then returning back to Earth but so far I have had no luck. Furthermore, I want to plot a Hohmann transfer and calculate the mass of fuel required for this mission. If...
  21. M

    B Biggest asteroid to pass Earth in 2021

    An asteroid that will be the largest during the year 2021 is expected to pass by about two million kilometers from Earth without the risk of colliding with it, but this astronomical event will allow scientists to study this celestial body more closely. This asteroid is called “2001 FO32”, and...
  22. S

    B What is the true density of the Asteroid Belt?

    Hello All Typical 'artist's impressions' of the Asteroid Belt show a large density of matter, see the attached view. Many unmanned spacecraft (and hopefully soon some manned ones) have crossed this belt, without encountering any asteroids, so how close is this view to the truth? Is there any...
  23. E

    I 4 spaceships are pulling a membrane through an asteroid belt

    Given 4 spaceships are pulling an elastic rubber membrane with constant speed and slow velocity into an asteroid belt. - In that way, that they all start in empty space and have a constant low speed of say 50km/h as they reach the belt. - The four edges of the membrane are tied to one of the...
  24. PolVD

    Solve 2D Asteroid Problem: Step-by-Step Guide

    Hi everyone! I don't know how to solve the next problem, and if anyone could explain to me step by step how it is solved I would thank you a lot. I know it's not hard, but I'm not seeing how to do it. Thank you in advance!
  25. Py3_3

    I Determining Relative Position of Space Object to Earth

    Hello, i'm doing a project where the goal is to get the relative position of a space object to the earth, roughly. Basically, i want to say that this object is currently e.g. above New York. The data for any given space object that i have is (It's sourced from an NASA API). The specific...
  26. T

    Sample and Return of Asteroid Bennu - live on Oct 20, 2020 at 1720 GMT

    Yeah, we're trying to get ahold of a physical sample of a pristine asteroid. Coverage starts at 1720 GMT (1:20pm EDT, 10:20am PDT) Live landing and capture at 2200 GMT (5pm EDT, 2pm PDT) https://www.nasa.gov/live/ https://www.space.com/17933-nasa-television-webcasts-live-space-tv.html...
  27. A

    I Can you See Neighboring Asteroids from an asteroid?

    It is well known that the asteroid belt is relatively sparse, with the asteroids spread out pretty far away from each other. From what I have read, asteroids are generally separated from other asteroids by about 500,000 to 1,000,000 km on average from their nearest neighbors. If I stood on an...
  28. Jarvis323

    Passive Aggressive Asteroid Sensationalism

    This isn't meant to be a serious post. This article had me laughing a little this morning. https://mynbc15.com/news/nation-world/massive-asteroid-taller-than-the-empire-state-building-headed-towards-earth-06-03-2020
  29. R

    B Could Asteroid Strikes Affect Mercury's Perihelion Advance?

    Einstein had solved the problem by introducing wrapping of space-time due to Sun as per general relativity. However, the predicted magnitude for other planets like Venus, Earth. Is it possible that additional force required for precession is due to asteroids striking force?
  30. O

    I How does Jupiter protect the Earth from collision with space rocks?

    I read (in "The View From The Center") that Jupiter protects the Earth from collision with large space rocks, asteroids, etc. What I can't get out of my mind is that could it also cause collisions. A large rock (initially not heading for Earth) could be put on a different path by Jupiter's...
  31. screamindivr145

    I Asteroid Response Help: Get Answers to Your Questions Here

    (If anyone could provide links to information it would be greatly appreciated.) I'm currently taking a class on threats from outer space and have to write a paper on something that could be done in response to an asteroid/meteor coming towards Earth. One of the quickest responses would be to...
  32. .Scott

    Harvard Team Discovers 'Hemolithin' Protein Series on Asteroid

    A Harvard teams believe they have found a protein series they call "Hemolithin" in an asteroid. Isotopes and other evidence indicates that it is not from a terrestrial source."Astrobiology Web" link arxiv pdf link
  33. T

    Throwing a baseball while standing on an Asteroid

    Summary:: Between the orbits of Mars and Jupiter, several thousand small objects called asteroids move in nearly circular orbits around the Sun. Consider an asteroid that is spherically shaped with radius r and density 2100 kg/m^3. a. You find yourself on the surface of this asteroid and throw...
  34. S

    I Would a rover on an asteroid float away because of the low gravity?

    I’m wondering if a lander/rover landed on an asteroid with a very low gravity, and we wanted to make said rover move around the asteroid, would it “float” away because of the low gravity? Wouldn’t the normal force and the gravitational force equal 0? If we added a propulsion system, how would we...
  35. alva3

    I How is asteroid 101955 Bennu possible?

    Summary: Five questions about the structure of asteroids; specifically 101955 Bennu. Please forgive my ignorance, but I need help reconciling a few things... I'm curious about the images I've seen of asteroid Bennu: 1. If gravity is proportional to combined masses divided by their distance...
  36. A

    Escape velocity of an iron asteroid

    Homework Statement: Jack can jump upwards a distance 1.4 meters when he is on the surface of the Earth. What is his initial velocity when he jumps? Most of the time, however, Jack is in space. He is an asteroid miner: he looks for asteroids made out of useful metals. His job involves landing on...
  37. M

    What happens if I speed up an Apollo group asteroid?

    Okay, having devised the antimatter bomb, I'm moving along to the concept of using Apollo group asteroids as freight trains for the inner solar system, but my knowledge of orbital mechanics is zilch. For example, (343158) 2009 HC82 appears to have a max speed of about 56 km/s at perihelion...
  38. G

    Can Particle Beams Effectively Vaporize Dangerous Asteroids?

    Lets suppose a space station is threatened by a meteor or some kind of space debris, and the station couldn't be moved fast enough. Could lasers, or particle beams become a realistic solution for that situation in not so far future? https://en.wikipedia.org/wiki/Particle-beam_weapon It talked...
  39. D

    How Should We Prepare for Potential Asteroid Collisions?

    I recently heard in the news that the small asteroid Apophis will be so close to Earth it will be within the Earth's satellite orbits. This asteroid will likely not hit earth, even if it did it wouldn't have an extinction level impact. But there will come a day when we will have to face off with...
  40. J

    I How can an asteroid get caught at a Lagrange point without a "brake"?

    Talking about the Jupiter Lagrange points at 60 degrees only. Hard to imagine a scenario where an asteroid comes from outside or inside the orbit of Jupiter and stops at a Lagrange point. That's like tossing a cone on a table and trying to make it end up standing on its nose. Or make the nose...
  41. M

    B Is the asteroid belt horizontal or like a dome?

    I see that most planets rotate around the sun in a horizontal circle, except for Pluto. My question is about the asteroid belt and the Kuiper belt. Are they horizontal or like a dome? As in can an object go “above” and “below” them in a totally open space? Also ... is it known and confirmed...
  42. J

    I Probability distribution of angle of asteroid entry to the atmosphere

    Used to play with gravitational attraction simulations ages ago. One thing I noticed it was difficult to get a small object to collide with a bigger spherical one vertically and far more likely to hit at an angle far from 0. Has the math of this been worked out for asteroids entering the Earth's...
  43. Mlesnita Daniel

    B Previous thoughts on destroying asteroids were wrong: Nuking them is a bad idea

    This study from Johns Hopkins University shows that even if we manage to nuke an asteroid and "destroy" it, it will have a core back, in almost 2 hours. Nuking them was a bad idea before, but now seems worse. More details here...
  44. jim mcnamara

    NASA NASA asteroid collision warning?

    Yup. Newspapers have it. Again. Note the example "news" article with a very tiny disclaimer. Here are wikipedia's take, some NASA information, and a news article. They are all links and therefore are transient and could change. https://en.wikipedia.org/wiki/2018_LF16...
  45. H

    Time required to change the velocity of an asteroid?

    Homework Statement So I am given a problem where I am asked to find the time it takes to change the velocity of an asteroid by 1m/s. In a previous section of the problem I was asked to find the force through which the asteroid is being propelled, which I calculated it to be F=1.3x10^4 N, and...
  46. Mlesnita Daniel

    B Ideas to protect the Earth from possible asteroid impacts

    Do you have any own idea, on a way to protect the Earth from a possible asteroid impact? (You can not use technologies that are not invented yet, or imaginary. Those that can be invented in the next, let's say, 10 years, are allowed)
  47. A

    Asteroid Impacts and Life on Earth

    Scientists say when asteroids showered on Earth they were the ones who brought water to Earth which started life. But how did few molecules of water started life on earth?
  48. BillTre

    NASA Contoversy about NASA's Asteroid Tracking

    Nathan Myhrvold has raised questions about the accuracy of data NASA uses to track asteroids that may impact the earth. Myhrvold is a former Microsoft chief technologist and a guy with many diverse interests. Specifically he has questioned the size information and how it was derived. This...