# Tag Info

149

This is an interesting question, but it lacks a key factor that is crucial to the answer: TIME. The point on Earth closest to the Sun varies through time, so the question can be asked about any moment in time, or over periods of time. Let's analyze the factors involved. At any given moment in time, the point on Earth's surface that is closest to the Sun is ...

29

The clouds can be seen moving but of course it's subtle at first glance. Frame 16: Frame 20:

27

They are moving, but not fast enough to notice at the distance shown. From the NASA page: These images were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image, reflecting the orbital tilt of Earth from the vantage point of the ...

11

The apparent anomaly, known as the Lunar Terminator or Moon Tilt Illusion, is indeed a matter of perspective. A brief explanation can be found here: http://chrisjones.id.au/MoonIllusion/ The essence: 'The illusion occurs when the moon and sun are separated by a wide angle, so that they are perceived relative to the horizon, as if in a panorama. A panoramic ...

11

The image is real, and the clouds are moving, they just move slow, as clouds do. The unnatural appearance arise because they are taken by DSCOVR at an extraordinarily large distance, from a place called L1, more than one million kilometers away!!!. The rotation of the Earth in the animation makes it difficult to distinguish the movement of the clouds, but ...

11

First of all, tides are not as simple as the "two-bulge" simplification. In reality, the diagram shown is misleading. The two bulges appear assuming an ocean of constant depth covers the entire surface of Earth. Clearly that is not the case and in the diagram you can see the continents. Considering the different sizes of the basins and the distinct ...

10

In short: No. Unless multi-million timescales are considered. The reason we keep teaching Newtonian mechanics, is because it is a VERY accurate approximation of a more general theory (general relativity) within the regimes of speed and gravity acceleration found in everyday life. Therefore, all the relativistic corrections to Newtonian mechanics in the ...

10

It is impossible to know. Solar flares can have more than 500,000 kilometers. So if we consider them part of the sun, the moment when the earth is closer to the sun can be very different from perihelion if a big flare happens, making much of what was discussed in other answers irrelevant.

10

Let's start by the quick rule of thumb, I'll follow the way I do it mentally as I think the mnemonics I use could help you too. First, the tropics are at 23.5° of latitude. And remembering that the original definition of meter is "A ten-millionth of an Earth's quadrant", it means the perimeter of Earth is 40,000 km, that consist on 360° of latitude, then: $... 8 Both the tropics of Capricorn and Cancer are 23.43692 degrees from the equator. So the angular distance between the two is 46.8738 degrees (2 x 23.437) of latitude. One nautical mile is defined as one minute of latitude. This is equivalent to one 1/60 of a degree. Thus, the distance between the tropics, along the surface of the earth is 60 x 46.8738 = ... 8 Tides arise from the differences in gravitational pull across an object. That's why their strength falls as$r^3$instead of$r^2$(where$r\$ is the distance between the two objects). Visually it can be understood as follows Does that makes sense? The key is to consider the differences in gravitational pull felt by the Solid Earth and both the water ...

7

The ecliptic path, is a well defined trajectory when displayed on the background of the fix stars like in the following figure (taken from physics.csbsju.edu) However, there is not such thing as an ecliptic path on the surface of the Earth. If you thought of it as the "Ground track" of a satellite but applied for the Sun, you have to consider that ...

6

As mentioned by Barry in the comments, you just have to substract 6 degrees of latitude to get the ring around areas were it never gets DARKER than civil twilight or darker for 24 or more hours (or 12° for nautical twilight and 18° for astronomical twilight). That would be: "Never darker than civil twilight circle": : 60° 33′ 46.7″ (orange in the figures ...

4

The point on the surface of the Earth where the Sun is currently immediately overhead is called the Zenith Point. Its Latitude and Longitude correspond to the Declination and Greenwich Hour Angle of the Sun. These data points can be approximated to any degree of accuracy and timeframe by a Fourier series of n terms. Accuracy sufficient for sextant work ...

4

This question can be answered in many different ways that take into account, or ignore, the many factors that affect the total output of a fix solar panel over a year. In general, all answers will agree that the solar panel will have to face the north in the southern hemisphere, and the south in the northern hemisphere. This is because that is the direction ...

4

Answers will be different because they must be tied to a model of solar evolution, and all models are a bit different. So to answer your question we have to select a model. A pretty standard and trusted one, is the one used in the paper Stellar evolution models for Z = 0.0001 to 0.03. Where Z stands for the metalicity of the star, that for the Sun they ...

4

What is happening here? Photoshop! The number of visible satellites plummets towards the middle of the night when more satellites fall into the shadow of the Earth, represented by the dark area on the left of the image. (emphasis added)

3

I don't see this point made, so I'll just add it. In very high gravitation situations orbital energy can be lost to "relativity" or more specifically, gravity waves. The primary relativistic effect that the Sun's gravity has on Mercury is an increase in it's precession, as @CamiloRada pointed out, and see more details here. A secondary relativistic ...

3

The latest positions that I am aware of say yes, but not in any useful way. From what I have read, the current prevailing opinion is that the weather of Earth is a chaotic system. Chaotic systems are known to be very sensitive to initial conditions. Eddys in the atmosphere that are mere milimeters in size may change whether it rains or shines on the other ...

3

As JeopardyTempest commented: Actually, the astronomical seasons are defined in such a way that you should expect them to be a full 1 ½ months behind, not just 21 days! Namely, astronomical winter only starts at the winter solstice, astronomical spring only starts at the equinox etc.. A more intuitive definition would arguably be if the seasons were centered ...

3

There are many models that estimate orbital parameters at long timescales. All of them rely in rather complicated formulas that account for the perturbations generated by other planets, the Moon, and many other factors. Some of the models even consider relativistic effects as described in this answer. An orbital solution that I often see cited and used in ...

2

This tool lets you determine daylight hours from latitude for any day of the year. I feel like this answer should be longer, but there is not much more to say.

2

You can just think of this in terms of energy. To leave a mark in the geologic record, you have to use something that is at least as strong as the forces that are shaping the world around you: erosion, melting, tectonic forces, wind and weather. These are all very energetic things that are happening around us all the time, and for long time spans. If you ...

2

No, it is not possible. The only thing I could think about is re/de/magnetisation of magnetic minerals. Even then I'm not sure it's feasible, because you to form a magnetic field you need an electric current in motion, but that's a question for physics, not here. So far, the major magnetic signals recorded in the geological history are well understood. ...

2

The density & composition of the meteoroid would be important. There are three main types of meteoroids: Iron Stone, & Iron-Stone Iron meteoroids are dense & would be somewhat resistant to burning up. Stone meteoroids are composed of grains of material. The composition of these meteoroids is 75-90 percent silicates. They tend to resemble ...

2

Whichever spot on the surface of the Earth is experiencing Lahaina Noon, or would be if it wasn't cloudy, is at the subsolar point and pointed directly at the Sun, moreso than any other point on Earth at that moment. Of course, you could get closer to the sun by climbing higher. If you were able to be at the summit of Chimborazo volcano in Ecuador (point ...

2

Something that I noticed in your formula is that you are using 365 for the amount of days in a year. Perhaps trying it using 365.25 would be more correct as it accounts for the leap year. Please let me know if this helps/corrects the issue.

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