The identity of the object that will hit the Moon in early March is still uncertain. Some of the story is in Why did we think that the object was gonna hit the Moon March 4th 2022? Who's been tracking and predicting it so closely? and more can be found in this (temporary?) Project Pluto post Corrected identification of object about to hit the moon

It could have been an asteroid, was then assigned to the DSCOVR mission upper stage, and is now currently assigned to China's Chang'e-5 T1 though apparently there's some pushback from China as well as based on some info from 18SPCS.

There is an interesting proposal on the Project Pluto page:

How did this mistake get past everybody? Aren't others tracking junk like this?**

As mentioned on my original page about this object, high-altitude junk has been of no concern to anybody outside the asteroid surveys, and even we haven't been all that fussed about it. Objects of this sort are not tracked by the US Space Force; they (mostly) use radar, which is 'near-sighted' : it can track objects four inches/10 cm across in low orbits, but can't see big rocket stages like this when they're as far away as the moon. You need telescopes for that.

Strange as it seems (to me, anyway), orbits are computed for objects of this sort only by me, in my spare time. Which leads to the question...

Should high-flying space junk be better tracked? Perhaps by an 'official' agency of some sort?

In the past, the limited work I did was probably sufficient. For the reasons described above, tracking deep-space junk wasn't all that major of a concern.

But many more spacecraft are now going into high orbits, and some of them will be taking crews to the moon. Such junk will no longer be merely an annoyance to a small group of astronomers. A few fairly simple steps would help quite a bit.

First, anybody launching objects into high orbits ought to make the last known state vector (where the object was and where it was going) publicly available, to some agreed-upon, centralized location that has some funding to do the job. SpaceX did have such a vector for the DSCOVR second stage, but it didn't get much distribution; I only learned of it very recently. (If I'd had it back in 2015, I probably would have recognized my mistake quickly.) The amateur radio community put together a state vector and orbital elements for the Chang'e 5-T1 stage, but that didn't get much distribution either and was also unavailable to me at the time.

Second, that centralized location ought to be the clearinghouse for observational data on high-orbiting junk, and should keep track of where such objects are going and make that data publicly available. (Basically, I'm asking for somebody to take over the job. They can use my software, which is all freely available, but I'm busy with asteroids.) This would be somewhat similar to the way in which the Minor Planet Center gathers observations of asteroids and figures out where they're all going.

I'd also advocate for attacking the problem on an international basis. This isn't just a US (or Chinese) problem.

Third, some thought should go into Keeping Outer Space Clean. (This already happens for low-orbiting objects, but everyone has been quite blasé about high-altitude junk.) The most recent Chinese lunar mission, Chang'e 5, put the booster into an orbit where it went past the moon, came back, and re-entered into the middle of the Pacific, far from any land mass. I hope that means CNSA has decided to dispose of space junk properly. (I don't know that they have; it could just have been sheer luck. If the upper stage of their next lunar mission goes into the ocean, we may suspect a pattern.)

"Proper disposition", by the way, may mean different things for different objects. For some, it could mean the Pacific Ocean; others might be best left to hit the moon, or put into solar orbit. The answer may not be the same for every bit of junk. But simply ignoring the issue, as has been (mostly) the policy to date, shouldn't be an option. It's an especially bad idea for objects for objects such as this, with orbits that bring them close to the moon. You get chaotic orbits in that case, where you really don't know where they'll eventually end up.

I've added some emphasis there for the purposes of this question, which is:

Question: For the Project Pluto proposal: "Should high-flying space junk be better tracked? Perhaps by an 'official' agency of some sort?" What would it take to implement?

In the Pod Bay I wrote:

The cost to what is proposed there is trivial. At these distances tracking is done with telescopes using the Sun to paint the objects (not radar) so it's mostly about coordinating information and probably only small adjustments to observing schedules of existing facilities, and getting launch providers to share their last known state vectors. So an office with a few desks with phones and computers, a few salaries...

Of course, as the Project Pluto proposal points out pointedly, it would also take some openness and cooperation, which means it might need some international standards of behavior.


1 Answer 1


Honestly if there isn't much there, we really don't need to track it, unless it is some kind of spy satellite.

LEO is very important to track, as collisions are likely. GEO is also similarly important, because of the large number of objects there.

LEO can easily be tracked by ground based assets, and there are special satellites to track GEO. All of this is done by https://www.space-track.org/ , which is the public outreach of the US 18th Space Control Squadron.

But for an object higher that Geostationary Orbit, but still around Earth, well, what harm would it do? There are very few objects that far out, and space is really big. Objects that far out aren't moving very fast either, so any potential impact would be low velocity. The main reason to track such objects is for asteroid spotting purposes really, I can't think of a reason to do so at this time.

Theoretically if one were to start tracking such objects one would either need a large number of space based assets that were closer to them, or just use big Earth assets. Being closer does help radar significantly, and optical a fair bit as well, but that is largely offset by launching said object to space. The space around Earth is just too large, more objects don't help. To see smaller objects requires a more focused beam, ensuring it takes longer to find anything.

Bottom line, tracking objects in deep space is hard and expensive, and there is little utility to doing it. These objects often are found by asteroid detection surveys, and specific tools to find satellites seems like a waste.


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