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10

My understanding is that the Earth's axis points in the same direction in space during its entire orbit around the sun. And this is what causes our seasons. The second statement is correct. The axial tilt is the primary driver of the seasons. The first statement is not exactly correct. There is a small but persistent change in the orientation of the ...


7

Picture the Earth as a small ball suspended in midair, not moving, although it's rotating on its axis. Unless forces are applied to it, absolutely nothing will happen. That's conservation of energy (or momentum; you can work with it either way). Earth will not spontaneously start moving in one direction because that would violate conservation of ...


4

Pluto and its largest moon Charon are tidally locked to each other. Charon and Pluto revolve about each other every 6.387 days. The two objects are both gravitationally locked to the other, so each keeps the same face towards the other. This is a mutual case of tidal locking . . . Because of Charon's large size compared to Pluto, and because its ...


4

The changing angle between sun and moon does cause some slight nutation in the earth's axis of rotation over an 18.6 year period. In the case of the Earth, the principal sources of tidal force are the Sun and Moon, which continuously change location relative to each other and thus cause nutation in Earth's axis. The largest component of Earth's nutation ...


4

It's pretty simple, actually. The Moon creates tides. Due to tides, the water bulges out towards the Moon (and also on the opposite side). But the Earth also rotates pretty fast (once a day), faster than the Moon orbits the Earth (once a month). There's friction between the rotating Earth, and the watery bulge created by tides. The rotation of the Earth ...


3

You know, the first time someone told me this, I was absolutely certain they were confused, ignorant, or otherwise mistaken, and I told him he had his facts wrong. To be precise, we were talking about an observer on the equator. I maintained that the Sun would rise due east and set due west, all year round. He said no. What gave me pause, though, is that ...


3

If you project the orbits onto a plane, for example the plane of the ecliptic, the projections will cross. But that's only because you're looking at a 3D problem in 2D. If you look at the orbits in 3D, you'll see that Pluto's orbit is highly inclined (17º) from the ecliptic, so it never actually passes through Neptune's orbit. Each time it seems to cross (in ...


3

For those who haven't seen it: Some human explorers land on a planet orbiting a black hole. The black hole is surrounded by a large accretion disk. The planet orbits at a distance such that going any closer to the black hole will mean that your odds of getting out are slim; it's also composed of water. Finally, time dilation from the black hole means that ...


2

The Earth acts like a massive gyroscope. A tremendous force would be required to change the orientation of the axis. While forces are certainly exerted, they are not large enough to cause appreciable change in the orientation of the axis as the Earth falls/orbits about the Sun. As you indicate, the orientation of the axis is responsible for the change in ...


2

Consider the case of similar-mass, close binary systems. If the orbital periods are less than a few days they are expected to become tidally locked on a timescale much shorter than the stellar lifetimes. In many cases the synchronisation can be established by comparing the rotation periods of the stars using modulation by starspots with the orbital period ...


2

How do scientists and astronomers recognize the perfect path or orbit (if it's orbiting an object) of an asteroid or a comet? They don't, and they can't. The best they can do is estimate the object's trajectory based on observations and based on techniques used to propagate the object (and other objects in the solar system) over time. These estimates ...


2

Lets Keep things simple. Below is a picture of the orbit of the Earth. I take the question to mean why the axis doesn't point toward the Sun all the time. The answer comparing the Earth to a Gyroscope is the easiest to use. The spinning effect on the axis does cause a force that helps keep the Earth's axis at a 23.5° angle (Approx) there is a slight wobble ...


1

To start with, such two orbits are extremely unlikely. First of all, any object orbiting a star and deviating strongly from a circular orbit has a high risk of crashing into something. As you notice, there are very few planets in our solar system, and all of them except Pluto have a very regular orbit. Planets which have intercrossing orbits would have ...


1

Because the Sun's gravitational pull on Earth is (nearly) uniform, it doesn't tilt the Earth, it only pulls it as a whole, without affecting the Earth's spinning around its own axis. The Earth's radius is ~ 6,400 km, the distance to the Sun is ~ 150,000,000 km, and the gravitational force diminishes as a square of a distance, so the ratio in the pull on ...


1

As a hint: a force directed inward does not change the angular momentum, and therefore does not change the semi-major axis nor the period. It's not clear which angle you're talking about, but knowing that the semi-major axis did not change should let you set the problem up as a simple geometry problem.


1

When material is shed from a comet, it mostly continues to follow the same orbit as the comet, but drifts out ahead or behind the comet in a complex way due to interactions with solar wind and the gravity of other objects. If you imagine the elliptical orbit of 55P/Tempel-Tuttle, it will have patches of denser dust in clumps spaced out around the ellipse ...



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