Posted by
CowboyNeal
on from the heavenly-bodies dept.
loconet writes "The BBC is reporting that astronomers have discovered the first object ever that is in a companion orbit to the Earth. Asteroid 2002 AA29 is only about 100 metres wide and never comes closer than 3.6 million miles to our planet."
Earth's second moon
by
EggplantMan
·
· Score: 5, Interesting
Not only is it co-orbital but it periodically gets trapped in earth's gravitational field to become a second moon:
General Simon Worden of the United States Space Command described it as a "near Earth object that is close to being trapped by the Earth as a second natural satellite".
...
In 550AD, and again in 2600AD and 3880AD, for a while it will become a true satellite of our planet, in effect Earth's second moon, although technically it will remain under the gravitational control of the Sun.
--
?-|||-----x<*))))><
Re:Earth's second moon
by
rebelcool
·
· Score: 3, Interesting
the orbit is as such that after orbiting earth for awhile, it builds the momentum to escape earth's orbit and fling itself back out and around the sun.
Interplanetary probes use this method all the time for escaping earth's gravity. After launch, they orbit the earth for awhile building up momentum (this is known as a 'gravity assist') then fling themselves out.
This is actually a much more common cosmic event than actually capturing something in permanent orbit. Doing that requires careful placement in the case of artificial satellites or just random chance in the case of natural ones.
--
-
600 years?
by
cybermace5
·
· Score: 5, Interesting
They claim it will be temporarily in earth orbit by 2600 AD. And then they go on to speculate on how important that would be to space exploration, possibly becoming the second object visited by astronauts.
If, in 600 years, we haven't sent astronauts to visit other planets, I have preemptively lost faith in the human race.
Come on, in 600 years we should have a pretty decent Mars colony going.
-- ...
Re:Not quite a planet, eh?
by
jamie
·
· Score: 5, Interesting
"In roughly the same orbit around the sun, a much smaller mass has to travel MUCH slower than the Earth to maintain that orbit."
No, any object in the same orbital path travels the same velocity.
Think about it this way. If I have a heavy object and a light object orbiting at Earth's distance from the sun, by your hypothesis one will travel faster than the other. So if I duct-tape them together they should travel at a speed somewhere in-between the fast one and the slow one. But the taped-together object masses the sum of both smaller objects so it should travel faster. It can't travel both faster than and slower than its larger half, so the hypothesis can't be right.
Re:Not quite a planet, eh?
by
MCZapf
·
· Score: 3, Interesting
I never quite understood the concept that an object in orbit is "falling around the sun (or earth)" until I read a physics book that got me to visualize this:
Imagine you have a cannon. You fire a cannonball out of it, and it follows a parabolic path until it hits the ground (Boom). Now, you get a more powerful cannon, and fire a cannonball even farther. In fact it's so powerful that the cannonball is traveling so fast horizontally that the ground is receding from it, due to the curvature of the Earth, faster than gravity is pulling it down to the Earth!
Tada! So the cannonball just keeps moving, around the Earth. It's in orbit.
I hope that explanation helps at least one person who was like me.
Zookeeper Hypothesis
by
gnarly
·
· Score: 5, Interesting
The Fermi Paradox asks: If intelligent life is common, given the billions of years since the formation of our galaxy, why have E.T.'s not yet reached (and perhaps colonized) Earth?
One proposed resolution is the Zookeeper Hypothesis, ie, they could have contacted us but are just waiting and watching for us to evolve, a la 2001.
If so, then wouldn't they want to put a probe near the Earth, which swoops down every few centuries or so for a close look, to see if any thing interesting has happened?
-- :-( is a registered trademark of Despair.com
Mr. Bass's Planetoid!
by
tekrat
·
· Score: 3, Interesting
Gosh doesn't anyone read the SF of children's writer Eleanor Cameron?
She wrote "The Wonderful Flight to the Mushroom Planet", but in "Mr. Bass's Planetoid", she created a tiny asteroid that allowed the two young protagonists to view the Earth while having landed their spaceship on this asteroid.
Next thing you know, the BBC will report that we've discovered Lepton! Watch out Mushroom People, we're coming!
-- If telephones are outlawed, then only outlaws will have telephones.
a real answer to Fermi
by
commodoresloat
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· Score: 4, Interesting
Or rather, a question; who's to say that other intelligent life in the universe is anything like our species? The idea that they can and should colonize us, study us, or even visit us seems like the height of anthropocentric hubris. They might not be "flesh-and-blood." They might have a completely different relation to matter and energy as we understand it. They might live in water. They might have no interest in enslaving us or looting our precious natural resources.
Confused...
by
abhinavnath
·
· Score: 5, Interesting
How is this object considered a "companion" while Cruithne - Earth's "second moon" - is not?
Is there an astronomer in the house? Or anybody who could clarify this?
-- My other sig is also a.Porsche
Re:Confused...
by
abhinavnath
·
· Score: 3, Interesting
I understand the difference between a satellite and a companion. However Cruithne and this body both follow spiral orbits in resonance with the Earth. Neither body orbits the Earth directly. I wanted to know why 2002 AA29 was described as the "first ever" companion object found when 3753 Cruithne was discovered in 1997, and given the discoveries of 1998 UP1 and 2000 PH5.
Re:Effect on Earth
by
nurightshu
·
· Score: 4, Interesting
I'm a firm believer in astrology, and I think that this type of object might play some role. [...] Thought?
Apparently not on your end of the connection, there's not. Now, I know we're supposed to be respectful of everyone's beliefs, no matter how crackpot or unfounded they may be, but come on! The URL is "science.slashdot.org," not "stuff-not-subject-to-empirical-proof,reason,or-ex perimentation.slashdot.org". This is a discussion about an asteroid in companion orbit (apparently of the L4 and L5 LaGrange points; see above), and you're wondering what effect it would have if 2002 AA29 were in the fifth house while Jupiter and Venus are in ascendance.
In the immortal words of "Weird" Al Yankovic, "Now, you may find it inconceivable or at the least a bit unlikely that the relative positions of the planets and the stars could have some special deep significance that applies exclusively to only you." I do. 2002 AA29 has been conclusively proven to exist. Has the "like, influence of the planets, man" been subjected to the same rigorous standards?
Didn't think so. Thank you, please drive through.
-- They that would sacrifice their.sig space for that cliched Franklin quote deserve neither.
Re:meters, miles...
by
mpe
·
· Score: 3, Interesting
You think that's bad? As a student pilot, I've learned that the aviation industry has the biggest problem with unit consistency.
There is a series of Discovery channel involving building a light aircraft, one of the first points the presenter made was that the construction involved using strange mixtures of units. You also have fuel load on commercial aircraft being measured as a weight, thousands of pounds; whilst dispensed as a volume; either litres, US gallons or imperial gallons depending where the plane fills up. Messing up the cacluations leading to a flight crew having to test the gliding abilities of an airliner over Canada.
I really wish us stubborn americans would just switch to SI...
The US signed the "Treaty of the metre" a long time ago, the US Congress explicitally has the power to set weights and measures so it's really a political problem.
Re:meters, miles...
by
gorilla
·
· Score: 3, Interesting
One plane crash was due to the crew having loaded so many pounds of fuel when they should have loaded so many kilograms instead...!
This was the Gimli Glider, which didn't crash, but did run out of fuel and had to make a dead stick landing on the abandoned RCAFB Gimli. No-one was seriously hurt. The aircraft, registration C-GAUN, serial number 22520, is still in service after $1M worth of repairs. Here are some photos from earlier this year.
Re:meters, miles...
by
tetranz
·
· Score: 3, Interesting
I'm curious. How much has the UK really changed? Are road distances Km or miles? And road speeds?
Twenty something years after New Zealand changed to metric I find it interesting and a little disappointing sometimes to observe the results.
Degrees F quickly disappeared because (I assume) of TV weather forecasts. MPH has gone because of car speedos but I think you would get blank looks if you asked a mechanic or tyre installer about pressure in Kpa.
Pounds and ounces seem to be long forgotten except for babies' weights.
Commercial floor space still seems to be advertised in sq ft, land area often in acres although I'm sure the official documentation is metric.
Off the cuff comments on TV by police etc at the scene of some event will often make it clear that feet and yards are still more comfortable than meters.
New born babies' weights are more often than not quoted in the newspapers in pounds.
Some adults still quote weight in stones (14 pounds?) although I doubt that you can even buy scales with stones now.
Slashdot Mirror
?-|||-----x<*))))><
They claim it will be temporarily in earth orbit by 2600 AD. And then they go on to speculate on how important that would be to space exploration, possibly becoming the second object visited by astronauts.
If, in 600 years, we haven't sent astronauts to visit other planets, I have preemptively lost faith in the human race.
Come on, in 600 years we should have a pretty decent Mars colony going.
...
No, any object in the same orbital path travels the same velocity.
Think about it this way. If I have a heavy object and a light object orbiting at Earth's distance from the sun, by your hypothesis one will travel faster than the other. So if I duct-tape them together they should travel at a speed somewhere in-between the fast one and the slow one. But the taped-together object masses the sum of both smaller objects so it should travel faster. It can't travel both faster than and slower than its larger half, so the hypothesis can't be right.
Imagine you have a cannon. You fire a cannonball out of it, and it follows a parabolic path until it hits the ground (Boom). Now, you get a more powerful cannon, and fire a cannonball even farther. In fact it's so powerful that the cannonball is traveling so fast horizontally that the ground is receding from it, due to the curvature of the Earth, faster than gravity is pulling it down to the Earth!
Tada! So the cannonball just keeps moving, around the Earth. It's in orbit.
I hope that explanation helps at least one person who was like me.
One proposed resolution is the Zookeeper Hypothesis, ie, they could have contacted us but are just waiting and watching for us to evolve, a la 2001.
If so, then wouldn't they want to put a probe near the Earth, which swoops down every few centuries or so for a close look, to see if any thing interesting has happened?
Gosh doesn't anyone read the SF of children's writer Eleanor Cameron?
She wrote "The Wonderful Flight to the Mushroom Planet", but in "Mr. Bass's Planetoid", she created a tiny asteroid that allowed the two young protagonists to view the Earth while having landed their spaceship on this asteroid.
Next thing you know, the BBC will report that we've discovered Lepton! Watch out Mushroom People, we're coming!
If telephones are outlawed, then only outlaws will have telephones.
Or rather, a question; who's to say that other intelligent life in the universe is anything like our species? The idea that they can and should colonize us, study us, or even visit us seems like the height of anthropocentric hubris. They might not be "flesh-and-blood." They might have a completely different relation to matter and energy as we understand it. They might live in water. They might have no interest in enslaving us or looting our precious natural resources.
How is this object considered a "companion" while Cruithne - Earth's "second moon" - is not?
Earth's Second Moon
2nd Moon Orbiting Earth Discovered
Google Search: Cruithne
Is there an astronomer in the house? Or anybody who could clarify this?
My other sig is also a
I'm a firm believer in astrology, and I think that this type of object might play some role. [...] Thought?
Apparently not on your end of the connection, there's not. Now, I know we're supposed to be respectful of everyone's beliefs, no matter how crackpot or unfounded they may be, but come on! The URL is "science.slashdot.org," not "stuff-not-subject-to-empirical-proof,reason,or-ex perimentation.slashdot.org". This is a discussion about an asteroid in companion orbit (apparently of the L4 and L5 LaGrange points; see above), and you're wondering what effect it would have if 2002 AA29 were in the fifth house while Jupiter and Venus are in ascendance.
In the immortal words of "Weird" Al Yankovic, "Now, you may find it inconceivable or at the least a bit unlikely that the relative positions of the planets and the stars could have some special deep significance that applies exclusively to only you." I do. 2002 AA29 has been conclusively proven to exist. Has the "like, influence of the planets, man" been subjected to the same rigorous standards?
Didn't think so. Thank you, please drive through.
They that would sacrifice their
You think that's bad? As a student pilot, I've learned that the aviation industry has the biggest problem with unit consistency.
There is a series of Discovery channel involving building a light aircraft, one of the first points the presenter made was that the construction involved using strange mixtures of units.
You also have fuel load on commercial aircraft being measured as a weight, thousands of pounds; whilst dispensed as a volume; either litres, US gallons or imperial gallons depending where the plane fills up. Messing up the cacluations leading to a flight crew having to test the gliding abilities of an airliner over Canada.
I really wish us stubborn americans would just switch to SI...
The US signed the "Treaty of the metre" a long time ago, the US Congress explicitally has the power to set weights and measures so it's really a political problem.
This was the Gimli Glider, which didn't crash, but did run out of fuel and had to make a dead stick landing on the abandoned RCAFB Gimli. No-one was seriously hurt. The aircraft, registration C-GAUN, serial number 22520, is still in service after $1M worth of repairs. Here are some photos from earlier this year.
I'm curious. How much has the UK really changed? Are road distances Km or miles? And road speeds?
Twenty something years after New Zealand changed to metric I find it interesting and a little disappointing sometimes to observe the results.
Degrees F quickly disappeared because (I assume) of TV weather forecasts. MPH has gone because of car speedos but I think you would get blank looks if you asked a mechanic or tyre installer about pressure in Kpa.
Pounds and ounces seem to be long forgotten except for babies' weights.
Commercial floor space still seems to be advertised in sq ft, land area often in acres although I'm sure the official documentation is metric.
Off the cuff comments on TV by police etc at the scene of some event will often make it clear that feet and yards are still more comfortable than meters.
New born babies' weights are more often than not quoted in the newspapers in pounds.
Some adults still quote weight in stones (14 pounds?) although I doubt that you can even buy scales with stones now.