General Astronomy

Anyone explain this? Super moon last night because it was closer to Earth in its orbit of Earth. Why? The moons orbit is influenced by the Earth's gravity, presumably a dropped object accelerates at the same speed if its dropped in the USA or Asia. Which means that the Earth's gravitational pull is the same around the globe. So why isn't the moons orbit a circle instead of being elliptical?
 
Psychedelic Casual said:
I don’t think humans’ brains are big enough to imagine the size of the universe
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“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”​

― Douglas Adams, The Hitchhiker's Guide to the Galaxy

Just about sums it up.
 
AlgarveBlu said:
Does that mean we have been singing the wrong song for 30 years and it should 'Blue Planet you saw me standing alone?' and that doesn't work as we could be singing about planet Earth as well - Shit! now we've got no science as well as no history :-(
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Haha! It does, best tell the boss to change the site think I’m disappointed the moon is a planet a fact I must have forgotten
 
Blue Llama said:
Anyone explain this? Super moon last night because it was closer to Earth in its orbit of Earth. Why? The moons orbit is influenced by the Earth's gravity, presumably a dropped object accelerates at the same speed if its dropped in the USA or Asia. Which means that the Earth's gravitational pull is the same around the globe. So why isn't the moons orbit a circle instead of being elliptical?
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Without looking it up, isn't it because of the suns gravity influencing the orbit and making it elliptical?
 
Centurions said:
Without looking it up, isn't it because of the suns gravity influencing the orbit and making it elliptical?
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The earth's gravity isn't equal. It changes as it's not a perfect sphere, and mass changes. The moon is actually gradually moving away from Earth.

Is the Moon moving away from the Earth? When was this discovered? (Intermediate) - Curious About Astronomy? Ask an Astronomer

Ask an Astronomer is run by volunteers in the Astronomy Department at Cornell University. We answer your astronomy questions. Please browse our archive first.
curious.astro.cornell.edu curious.astro.cornell.edu
 
ultimateharold said:
The earth's gravity isn't equal. It changes as it's not a perfect sphere, and mass changes. The moon is actually gradually moving away from Earth.

Is the Moon moving away from the Earth? When was this discovered? (Intermediate) - Curious About Astronomy? Ask an Astronomer

Ask an Astronomer is run by volunteers in the Astronomy Department at Cornell University. We answer your astronomy questions. Please browse our archive first.
curious.astro.cornell.edu curious.astro.cornell.edu
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I didn't know that (or possibly forgot) although that doesn't answer the original question.

It's (inevitably) much more complicated than I stated about the sun affecting it as everything effects it.

Just the Intro section answers their question I think, the rest will possibly just give you a headache (well, it did me anyway).

NASA - Eclipses and the Moon's Orbit

This is part of NASA's official eclipses web site.
eclipse.gsfc.nasa.gov

Edit: if anyone wants to read a hard science apocalyptic novel that has a lot of info about gravity and orbits then try Neal Stephenson's "Seveneves", awesome book.
 
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Blue Llama said:
Anyone explain this? Super moon last night because it was closer to Earth in its orbit of Earth. Why? The moons orbit is influenced by the Earth's gravity, presumably a dropped object accelerates at the same speed if its dropped in the USA or Asia. Which means that the Earth's gravitational pull is the same around the globe. So why isn't the moons orbit a circle instead of being elliptical?
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Because the earth and the moon are both orbiting a much larger object…
 
JRockBlues said:
Are you sure?

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The Earth only has one known moon, Cruithne is in an eccentric orbit around the Sun which makes it appear to be in orbit around the Earth at certain times of the year. According to QI the one thing you can definately say about the show is that it is often wrong.
 
Blue Llama said:
Anyone explain this? Super moon last night because it was closer to Earth in its orbit of Earth. Why? The moons orbit is influenced by the Earth's gravity, presumably a dropped object accelerates at the same speed if its dropped in the USA or Asia. Which means that the Earth's gravitational pull is the same around the globe. So why isn't the moons orbit a circle instead of being elliptical?
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The Earth and Moon orbit a common centre of gravity which because of the relative mass of the two objects lies inside the Earths circumference, seen from a distance this would make the Earth appear to wobble, the Moon like most moons and planets orbits on a path that is almost but not quite circular. Finaly because the Moons sidereal rotation is gravitationaly locked (it always keeps the same side towards the Earth) the coservation of angular momentum forces the moon into a higher orbit. Right I've run out rubbish about the moon, I'm gonna crawl back under my rock.
 
lyonfish said:
The Earth only has one known moon, Cruithne is in an eccentric orbit around the Sun which makes it appear to be in orbit around the Earth at certain times of the year. According to QI the one thing you can definately say about the show is that it is often wrong.
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They had one episode where they gave back points for previously wrong answers. Alan gained many many points, as did 2 of the other guests (jo brand + ?)… and then there was another panellist - 1st time on… who still had to start on nothing!

Iirc it’s the usual bell curve of now wrong answers versus time. Something like 80% from series A
 
Alan Harper's Tash said:
This new telescope is amazing.

View attachment 49800
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I love that image and it made me laugh, but on a serious note, the telescope has the ability to analyse the composition of the atmospheres of exoplanets when they pass in front of their suns.

It's mind blowing when you consider SETI has been scouring the heavens for signs of life from the detection of radio waves for decades without success, but this new telescope can detect chlorophyll or chemicals that are the result of industrial pollution on planets far away from us, and there are thousands to look at in detail.

The resolution of the mirror is so advanced, it can look further back in time than the Hubble telescope. Hubble took a blurry picture of a galaxy that is 13.6 billion years old, the oldest thing ever to be seen in the cosmos, and formed just a few hundred million years after the creation of the universe.

This new telescope can focus on that blurry image, and see past it. It's possible pictures will be taken of the very first stars that formed just 100 million years after the big bang.

The discoveries it will make over the coming years will advance our knowledge of the universe faster than anything we have had in the past.

Ducks on Jupiter may be a little far fetched, but if there is life out there, we now have the capability of finding it.

It's an exciting time for space buffs like me.
 
NPBlue said:
I love that image and it made me laugh, but on a serious note, the telescope has the ability to analyse the composition of the atmospheres of exoplanets when they pass in front of their suns.

It's mind blowing when you consider SETI has been scouring the heavens for signs of life from the detection of radio waves for decades without success, but this new telescope can detect chlorophyll or chemicals that are the result of industrial pollution on planets far away from us, and there are thousands to look at in detail.

The resolution of the mirror is so advanced, it can look further back in time than the Hubble telescope. Hubble took a blurry picture of a galaxy that is 13.6 billion years old, the oldest thing ever to be seen in the cosmos, and formed just a few hundred million years after the creation of the universe.

This new telescope can focus on that blurry image, and see past it. It's possible pictures will be taken of the very first stars that formed just 100 million years after the big bang.

The discoveries it will make over the coming years will advance our knowledge of the universe faster than anything we have had in the past.

Ducks on Jupiter may be a little far fetched, but if there is life out there, we now have the capability of finding it.

It's an exciting time for space buffs like me.
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It was a little tongue in cheek on my part.

I studied physics to A level and maintain an amateur, yet excited interest in what we are finding, what we are improving and what we will continue to find out.

”Aliens” must exist, whether at microbe or Death Star level.

it’s utterly mind blowing what they are showing us. we’ll to me anyway.
 
Blue Llama said:
Anyone explain this? Super moon last night because it was closer to Earth in its orbit of Earth. Why? The moons orbit is influenced by the Earth's gravity, presumably a dropped object accelerates at the same speed if its dropped in the USA or Asia. Which means that the Earth's gravitational pull is the same around the globe. So why isn't the moons orbit a circle instead of being elliptical?
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Because its made of cheese. Ffs, didn't you learn anyfink at school?
 
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