Like diverting meteor path away from Earth, or blasting giant asteroid which was expected to impact Earth, etc.

Has any space agency saved Earth from a major calamity at any time?

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    $\begingroup$ Does detecting the effect of CFCs on the ozone layer count? $\endgroup$
    – 0xDBFB7
    Commented Apr 24, 2022 at 21:07
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    $\begingroup$ Weather satellites being used in Hurricane and Tsunami warnings, Earth-observation satellites being used during natural and humanitarian disasters, Satellite communications being used during humanitarian relief efforts. Also, our modern world wouldn't function without GNSS. And it's not even necessarily the navigation aspect, but the time synchronization aspect that is more important. Cancer research performed on the ISS. $\endgroup$ Commented Apr 24, 2022 at 22:53
  • $\begingroup$ Clearly the dinosaur's NASA analogue didn't do its job... $\endgroup$
    – Jon Custer
    Commented Apr 26, 2022 at 14:21
  • $\begingroup$ Do you mean in fiction or real life? $\endgroup$ Commented Apr 27, 2022 at 0:19
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    $\begingroup$ @QuoraFeans Ofcourse real. $\endgroup$
    – K. Yuta
    Commented Apr 27, 2022 at 5:24

6 Answers 6


More fundamental, and a question if it counts as a 'space agency' act being NOAA led but weather satellites not only reduced the fatalities associated with weather data collection but increased the number of dangerous weather events to be forecast days rather than hours in advance.

Weather satellites are among the first 'working' satellites arguable beating communication and navigation

It is arguable that for areas with large amounts of ground stations available it would be possible to work without satellite data, but for areas where the weather comes from over the ocean expensive and risky networks of surface ships* would be required, especially when the most important time to have them at sea is when extreme weather is likely. Satellites are mostly immune to the extreme weather they measure.

*While weather buoys exist for surface data, in the absence of satellite upper atmosphere data something capable of doing balloon and radar operation would be required, probably requiring crewed ships.

  • $\begingroup$ Many things changed with the onset of the "satellite era", including communication, weather forecasting, observing climate change, and navigation. $\endgroup$ Commented Apr 25, 2022 at 17:29
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    $\begingroup$ Could do with a hurricane image. Mapping can also stop tankers from capsizing and people from wandering into dangerous places... $\endgroup$ Commented Apr 25, 2022 at 23:45
  • $\begingroup$ possible to work without satellite data — possible is relative, but it would not be realistically possible to get the current quality of numerical weather prediction no matter how many ground stations you have, because satellites can uniquely see the top of the clouds as well as what is above. It would take many thousands of stratospheric balloons. $\endgroup$
    – gerrit
    Commented Apr 26, 2022 at 7:56
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    $\begingroup$ Those buoys in the middle of the ocean do not have an electronic connection by which to relay their data. They instead relay the collected data to satellites in geosynchronous orbit or low earth polar orbit. Those buoys would be rather useless were it not for satellites. $\endgroup$ Commented Apr 26, 2022 at 10:10
  • $\begingroup$ @DavidHammen that sounds like an electronic connection via a satellite $\endgroup$ Commented Apr 27, 2022 at 8:58

Ozone depletion was hypothesized and first measured without the means of satellites according to the wikipedia article. However, satellite data was apparently very helpful in showing the scope/size and history of the problem, which led to a rapid change in public policy, thus reducing the harm inflicted.


Has any space agency saved Earth from a major calamity at anytime?

There are historians who believe that the US–Soviet and US–Russian collaboration, for example in the Apollo–Soyuz Test Project, the Shuttle–Mir Project, and ultimately the merging of Мир-2 and Space Station Freedom into the International Space Station had at least a partial hand in preventing the Cold War becoming hot, including preventing a Nuclear War.

In that sense, NASA and Роскосмос (and its predecessors) may have prevented the annihilation of (a significant portion of) humankind.

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    $\begingroup$ In addition, one could plausibly argue that the race to land men on the moon, won by the civilian US space agency, served as a safety valve of sorts for the arms race during the cold war, and that of course was the predecessor of the joint missions listed in the answer. $\endgroup$ Commented Apr 26, 2022 at 14:34
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    $\begingroup$ The question was whether Earth was saved. The continuation of the human race is almost definitely not a positive in that context. $\endgroup$ Commented Apr 27, 2022 at 10:56
  • $\begingroup$ @AdamBarnes while such interpretations are widely known (e.g. "The Day the Earth Stood Still"), it does not seem to be what poster is asking about (i.e. Earth itself does not need "saving" from meteor impacts, as planet itself couldn't care less) $\endgroup$ Commented May 4, 2022 at 12:10

As yet, no space agency has blasted anything that may have posed a hazard to Earth. One of the issues with blasting such hazards is the numerous fragments of the blasted object may pose a greater risk to Earth than the larger singular object.

In such instances it would be better to blast near the object to alter its course. One of the problems with this is such objects are usually detected when it is too late to act.

So far, all that agencies can do is warn us of threats or potential threats, such as comets, asteroids, solar flares and high energy beams.


Like diverting meteor path away from Earth or blasting giant asteroid which was expected to impact Earth etc.

Not yet.

However, later this year (between 26 September 2022 and 2 October 2022), NASA's and ESA's Double Asteroid Redirection Test mission will (attempt to) alter the course of the asteroid-moon Dimorphos with a kinetic impactor.

Note that this test is deliberately performed with an asteroid that is not Earth-crossing to avoid accidentally knocking it into a collision course. So, it does not quite the bill of "diverting away from Earth", but it is "diverting".

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    $\begingroup$ That planned mission is a training/practice run so we can learn exactly how to divert dangerous objects in case we need to save the Earth from a future impact. The ultimate goals are to be able to 1. Divert incoming objects and 2. Divert useful objects into easier to reach orbits (like around the Earth or the Moon for easier mining access). $\endgroup$
    – Kyle A
    Commented Apr 25, 2022 at 12:03
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    $\begingroup$ @KyleA 2: what could possibly go wrong...? 🤣 $\endgroup$ Commented Apr 25, 2022 at 18:26
  • $\begingroup$ @KyleA I remember hearing about a comet that will get near Earth, which will alter its path because of the attraction, and that could either lead it into hitting Earth or not in the following years (2025?). $\endgroup$
    – Clockwork
    Commented Apr 25, 2022 at 18:34
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    $\begingroup$ @Clockwork: I don't think it's all that unusual with earth-crossing asteroids. Any time anything like that makes a close enough approach to Earth, even though known not to hit us, it becomes more difficult to predict its trajectory afterwards than it would be if it stayed well clear of anything. So after such a close approach you can make measurements of the orbit afterwards that add precision to what the predictions said beforehand. $\endgroup$ Commented Apr 26, 2022 at 4:14
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    $\begingroup$ I don't know anything about the detailed modelling (other than ofc that I'm aware of both Newtonian mechanics and general relativity, very much entry-level). But I think basically this is because "close" means "steeper gradient in the gravity field", which magnifies the error bars over time more than what happens when "nowhere near anything big". Extreme case, if some object was going to skim the atmosphere then it becomes very chaotic where it goes next. You don't know exactly what the force on it will be. So it's tricky for example to predict where some de-orbited satellite will splash down. $\endgroup$ Commented Apr 26, 2022 at 4:19

No, it hasn't happened, no matter what some people may want to believe. If anything, the opposite is actually the case.

In 1983, a Soviet human operator Lieutenant Colonel Stanislav Petrov has saved Earth from a Soviet space agency maintaining an early-warning system named "Oko" (eng. "Eye) whose false alarm could have caused a total disaster of nuclear war. On September 26th, 1983, that system reported supposedly a few nuclear missiles approaching USSR, and the official procedure was telling Lt Col. Petrov to report that to his superior who would almost certainly had launched an enormous retaliatory strike as means of mutually-assured destruction. Lt Col. Petrov correctly came to the conclusion that it was a false alarm since it made no sense for, and dismissed the alarm as invalid, most possibly saving life on Earth from destruction.

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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage
    Commented Apr 27, 2022 at 14:11

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