# Amateur Astronomer Discovers possible new Moon orbiting Earth **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [September 11, 2002, 6:57pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003 "2002-09-11T18:57:48Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\ **Post date:** [September 11, 2002, 6:57pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/1 "2002-09-11T18:57:48Z")
Here’s [the story](http://news.bbc.co.uk/2/hi/science/nature/2251386.stm): > [@](#): > > _From BBC News_ > An amateur astronomer may have found another moon of the Earth. Experts say it may have **only just arrived**. Think of the sci-fi potential: “General, that’s not a moon, it’s an alienspaceship!” But here’s my favorite part: > [@](#): > > If it is determined that J002E2 is natural it will become Earth’s **third** natural satellite. > > Earth’s second one is called Cruithne. It was discovered in 1986 and it takes a convoluted horseshoe path around our planet as it is tossed about by the Earth’s and the Moon’s gravity. I never knew that. Sure that could win a few bar bets. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [September 11, 2002, 7:37pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/2 "2002-09-11T19:37:52Z")
Whatever happend to the one reported in the late 1970s and called “Toro”? ---
**Author:** ![Jenericho](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@Jenericho](https://boards.straightdope.com/u/Jenericho)\ **Post date:** [September 11, 2002, 8:36pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/3 "2002-09-11T20:36:45Z")
FWIW, the Moon’s not a satellite of the Earth; its path round the Sun is never retrograde so we’re just one half of a biplanetary system. So, the Earth-Moon-biplanetary-conglomerate now has a _second_ known satellite! ---
**Author:** ![RTFirefly](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)\ **Post date:** [September 11, 2002, 9:19pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/4 "2002-09-11T21:19:55Z")
> [@](#): > > \*Originally posted by Jenericho \* > FWIW, the Moon’s not a satellite of the Earth Yeah, but we’ve got all the air and water, so who cares? 😉 ---
**Author:** ![RTFirefly](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)\ **Post date:** [September 11, 2002, 9:49pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/5 "2002-09-11T21:49:25Z")
I’ve been reading [this page](http://www.astro.queensu.ca/~wiegert/3753/3753.html) which is written by astronomers in order to explain such things to semi-intelligent laymen. They don’t use the word ‘satellite’ with respect to Cruithne, and for good reason, it seems. It’s co-orbital with the Earth (that is, it goes around the sun in something approximating Earth’s orbit), but they call it a ‘companion’ body rather than a satellite. It can be on the other side of the Sun from the Earth, and in the near future, it won’t get any closer than 0.3 AU. (An AU is the mean Earth-Sun distance, ~93M miles.) The linked site describes Cruithne’s orbit, and it has to be read to be believed. They also have little movie simulations, which help. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [September 12, 2002, 5:29pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/6 "2002-09-12T17:29:24Z")
Bummer. Looks like that ‘third moon’ may be an old [Apollo booster](http://news.bbc.co.uk/2/hi/science/nature/2253385.stm). ☹ ---
**Author:** ![bup](https://avatars.discourse-cdn.com/v4/letter/b/6bbea6/32.png) [@bup](https://boards.straightdope.com/u/bup)\ **Post date:** [September 12, 2002, 5:38pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/7 "2002-09-12T17:38:11Z")
> [@](#): > > \*Originally posted by Jenericho \* > \*\*FWIW, the Moon’s not a satellite of the Earth; its path round the Sun is never retrograde so we’re just one half of a biplanetary system. So, the Earth-Moon-biplanetary-conglomerate now has a _second_ known satellite! \*\* This has been discussed at the Bad Astonomy bulletin boards. Given that there’s no hard definition of ‘planet,’ the contention that the moon is half of a biplanetary system is only a contention, and not a black-and-white fact. I’ve never heard that the litmus test for a moon was that it go retrograde wrt the star at some point. I _have_ heard it contended that a moon is a moon if the gravitational center between the planet and moon is inside the planet. In that case, our moon is indeed a moon. ---
**Author:** ![zuma](https://avatars.discourse-cdn.com/v4/letter/z/e9c0ed/32.png) [@zuma](https://boards.straightdope.com/u/zuma)\ **Post date:** [September 12, 2002, 6:05pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/8 "2002-09-12T18:05:15Z")
I’d like to know where I go to get the 15 seconds of my lfie back that I wasted on this thread. maybe it was my own fault, but stiill. ---
**Author:** ![ShibbOleth](https://avatars.discourse-cdn.com/v4/letter/s/848f3c/32.png) [@ShibbOleth](https://boards.straightdope.com/u/ShibbOleth)\ **Post date:** [September 12, 2002, 6:34pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/9 "2002-09-12T18:34:40Z")
> [@](#): > > \*Originally posted by Sunspace \* > \*\*Bummer. Looks like that ‘third moon’ may be an old [Apollo booster](http://news.bbc.co.uk/2/hi/science/nature/2253385.stm). ☹ \*\* Ha! That’s just what _they_ want you to believe. Don’t fall for it; the aliens have probably controlled our leaders minds already, or seduced them with new technologies. **Zuma** , you can get the 15 seconds back, but first you have to fill out some forms. ---
**Author:** ![bernse](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@bernse](https://boards.straightdope.com/u/bernse)\ **Post date:** [September 12, 2002, 7:20pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/10 "2002-09-12T19:20:25Z")
I was hoping it was the Apollo 10 Lunar module, _Snoopy_. That would be a neat relic to get back… although it would probably be infested with Space Vampires by now. ☹ ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [September 12, 2002, 7:33pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/11 "2002-09-12T19:33:25Z")
> [@](#): > > \*Originally posted by Sunspace \* > \*\*Bummer. Looks like that ‘third moon’ may be an old [Apollo booster](http://news.bbc.co.uk/2/hi/science/nature/2253385.stm). ☹ \*\* Can’t be. Remember, we never went, NASA faked the whole thing, so it’s gotta be a brand-new moon! 😉 ---
**Author:** ![Angua](https://avatars.discourse-cdn.com/v4/letter/a/8baadc/32.png) [@Angua](https://boards.straightdope.com/u/Angua)\ **Post date:** [September 13, 2002, 11:22am UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/12 "2002-09-13T11:22:37Z")
Aargh! I’ve been out of the loop too much. This is what comes of doing extra-galactic astronomy, you become out of touch with the wierd and wonderful things in your own backyard… Still, Cruithne came as news to me… ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [September 13, 2002, 11:35am UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/13 "2002-09-13T11:35:47Z")
> [@](#): > > \*Originally posted by ShibbOleth \* > \*\* > > Ha! That’s just what _they_ want you to believe. Don’t fall for it; the aliens have probably controlled our leaders minds already, or seduced them with new technologies.\*\* That would certainly explain a lot, wouldn’t it? Hmm… ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [September 13, 2002, 11:46am UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/14 "2002-09-13T11:46:23Z")
Can’t they remember where they parked that thing? ---
**Author:** ![Baldwin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/baldwin/32/7264_2.png) [@Baldwin](https://boards.straightdope.com/u/Baldwin)\ **Post date:** [September 13, 2002, 3:59pm UTC](https://boards.straightdope.com/t/amateur-astronomer-discovers-possible-new-moon-orbiting-earth/128003/15 "2002-09-13T15:59:51Z")
> [@](#): > > FWIW, the Moon’s not a satellite of the Earth; its path round the Sun is never retrograde so we’re just one half of a biplanetary system. I’ve never heard of this criterion. Wouldn’t that be true not only for the Moon, but for every natural and artificial object orbiting the Earth, given that our orbital speed around the sun is about 60,000 mph, and orbital velocity around the Earth is about 17,000 mph and down? As I recall, the Apollo 13 second stage actually ended up on the Moon, but most of them are still in their own orbits. There may be examples of human technology drifting in space long after our civilization has destroyed itself.