Planetary Science

no one has gone to mars yet but there's still curiosity the rover that went to mars

Early astronomers believed in the geocentric model because it appeared to explain the motion of celestial bodies in the sky. The model was supported by the apparent daily motion of the sun and stars around the Earth. Additionally, there was a philosophical and religious belief at the time that Earth was the center of the universe.

Since earth is the only planet we know that has life manyscientists go by what is found here on earth. So, you will need water, oxygen, heat, nitrogen ,and various other chemicals. In addition, some form of food to sustain life living on the planet.

The most important force during the creation and formation of a new solar system is gravity. Even before the system's creation, gravity aggregates the gases and dust to form the star that will become the system's sun.

Planets follow the laws of gravity as described by Sir Isaac Newton and detailed by Johannes Kepler. ... But not quite... Einstien discovered something years later that will blow your mind if you take the trouble to check it out.

You would have learned a lot more (and still can) by looking deeper.

JCF

It depends on the context. In terms of a human lifespan, one year may not seem long. However, in the context of waiting for something or planning an event, one year may be considered a significant amount of time.

One way to divide the planets could be by classifying them as terrestrial planets (Mercury, Venus, Earth, Mars) and gas giants (Jupiter, Saturn, Uranus, Neptune). Terrestrial planets are small, rocky, and have solid surfaces, while gas giants are much larger, composed mainly of gases and liquids, and lack a solid surface.

Mars is the fourth smallest planet in our solar system. It is smaller than Earth, Venus, and Uranus, but larger than Mercury and Pluto. It is the second smallest of the terrestrial planets, with Mercury being the smallest.

The sun is at its highest point in the sky at noon because that is when it is directly overhead an observer at the equator. This position is a result of the sun's path across the sky due to the Earth's rotation.

The curving of winds and ocean currents caused by Earth's rotation is called the Coriolis effect. This phenomenon deflects moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. It is a result of the rotation of the Earth on its axis.

You would have thought it to be Mercury as its the closest to the sun, but its actually Venus, the second closest.

Venus gets hotter as the thick carbon Dioxide atmosphere holds the heat more effectively, while Mercury has no atmosphere.

The solar system appears flat when viewed from the side because the planets orbit the sun in roughly the same plane called the ecliptic. This alignment creates the appearance of a flat disk when observed from a different perspective.

The red planet that humans have sent robots to is Mars. NASA and other space agencies have sent rovers and landers to explore the Martian surface and gather data about its geology and atmosphere.

Yes, the sun's mass is a crucial factor in controlling the motions of the planets in our solar system. The sun's gravitational force keeps the planets in orbit around it, shaping their paths and governing their speeds. The more massive an object, like the sun, the stronger its gravitational pull on surrounding objects.

The distance of the Earth from the sun does not contribute to the changing seasons. Although this distance does change (since the Earth's orbit is elliptical, not perfectly circular) the amount of the change is not great enough to affect the seasons. It is the angle of incidence of solar radiation, which in turn is affected by the axial tilt of the Earth and its revolution around the sun, which creates the changing seasons.

Yes, it is the region beyond Neptune that extends to the edge of the solar system. Like the asteroid belt, this area contains left over parts that did not make it when the solar system was created. Pluto, comets, and other small and tiny items are scattered out here.

No, our solar system has one sun, which is known as the star we call the Sun.

"You can see this in practical terms by making an ellipse yourself. Put two thumbtacks about four inches apart in a paper-sized piece of cardboard. (These distances are arbitrary, but it will get you started.) Next, tie a loose-fitting string, about seven inches long or so, between the two thumbtacks. Finally, place a pencil inside the string and pull it away from the tacks until the string is taut. The string will look like a triangle with the pencil and the two tacks in the corners. Move the pencil all the way around the cardboard, keeping the string taut, and you will draw an ellipse.

This is illustrated in Figure 2. For the purposes of this article, "F1" will be the left focus point for a horizontal ellipse, or the top focus point for a vertical ellipse. Similarly, "F2" will be the right or bottom focus point, for horizontal or vertical ellipses, respectively.

Now that you've drawn your ellipse, you can move from arts and crafts to astronomy. In 1609, Johannes Kepler reasoned that the planetary orbits were not circular as once thought, but were elliptical with the Sun at one of the two focus points of the elliptical orbit. So, to simulate an orbit, you must be able to determine the location of the foci, and use one as the Sun.

Calculating the Foci

To calculate the focus points, you need to know a few basic things. Using correct terminology, the longest axis, going through the two focus points, is called the major axis. The axis perpendicular to this axis at the center of the ellipse is called the minor axis. Half the major axis, marked in Figure 2 by a, is called the semimajor axis. Half the minor axis, indicated as b in Figure 2, is called the semiminor axis.

Often, the first time learning a subject, it's helpful to work with terms you are comfortable with. To simplify, I'll use the terms "width" and "height," and "xRadius" and "yRadius" when discussing the major, minor, semimajor, and semiminor axes, respectively. There's still one more thing you have to figure out before you can continue.

To find the focus points of an ellipse, you must calculate the eccentricity of the ellipse. This is how elongated it is. Once you know the eccentricity of an ellipse, you can multiply this factor by the "xRadius" (or a in Figure 2) to get the distance from the center point to a focus point. This is marked by ae in Figure 2 and is the offset distance you'll use in your script to move the ellipse to the correct new location.

There are a few ways to calculate the eccentricity of an ellipse. The formula I'll use is:

(If you're interested in knowing how this formula was derived, check out the Related Resources on ellipses, left column.) Writing that in ActionScript, using the aforementioned simplified terms, the formula becomes:

e = Math.sqrt(1 - (yRadius*yRadius) / (xRadius*xRadius))

where Math.sqrt() is the Math object notation for square root.

Once you have the eccentricity of the ellipse, all you have to do is multiply that by the "xRadius" (in the case of our horizontal ellipse) to get the distance from the center of the ellipse to one of the focus points around which you can orbit your MovieClip. You may wish to orbit a MovieClip around a specific point, or it might even be the location of another MovieClip. For example, you might again want your example to show the Earth orbiting the Sun and the Moon orbiting the Earth.

But which focus point should you use? Since the ae (or xRadius * e) distance you just calculated is the same from the center to each focus point, the last step you need to take is to determine how to apply the offset. One method would be to use a conditional statement (if or switch, for example) to specify whether you add or subtract the offset from the center point of your ellipse. But there is a simpler way. If you use -1 to represent the left/top focus, 0 to represent the center, and 1 to represent the right/bottom focus, you can multiply the ae offset by this factor and subtract it from the desired anchor point.

For example, say you are placing your ellipse in the center of your stage at (275,200); you have an ellipse that is 250 pixels wide and 150 pixels tall. This results in an eccentricity of .8. Since your ellipse is 250 pixels wide, the "xRadius" is 125, or half the width. Therefore, the x offset would be calculated like this:

centerX -= (xRadius * e) * ellipseFocusPoint;

1) -1 for left focus point

275 -= (125*.8) * -1

275 - (-100)" - alex from yahoo answers

Traveling at 100 km/h, it would take over 58,000 years to reach the nearest star, Proxima Centauri, which is about 4.24 light years away. The vast distance and the limitations of current spacecraft speeds make interstellar travel a significant challenge with our current technology.

The star that gives off more light is likely larger and hotter than the other star. The brightness of a star is directly related to its size and temperature, with larger and hotter stars emitting more light.

If you stood at the north pole and jumped up to look down on our solar system, the earth would be orbiting counter-clockwise, as well as spinning counter-clockwise. The moon would also be orbiting counter-clockwise, as well as spinning counter-clockwise at 1 revolution per orbit. The Earth then rotates 366.25 times per year approximately, which makes for 365.25 days since one is taken up by orbiting the sun.

The Inuit country experiences periods of continuous daylight and continuous darkness due to its high latitude near the North Pole. This phenomenon is called the midnight sun during summer when the sun does not set for several weeks, followed by polar night during winter when the sun does not rise for several weeks.

Far enough from the new Sun that they did not "evaporate". In other words,

towards the outer rim of the main part of the disk.

Aristotel said that earth revole around the sun when people thought sun rotate around the earth. With the help of lunar and solar eclipse he found out this. Next galileo galalia absorbed a planet with his microscope three point revole around that planet and ay days 4th point also appeared they revole around that planet then he concluded that earth only revole around the sun. The point is moon. For info see curiasity did god create universe