Why is the temperature in space and on Earth different?
When we describe weather on Earth, we talk about several interrelated factors such as temperature, wind speed and direction, humidity, precipitation, barometric pressure, cloud cover, and so on. Similarly, when we speak of space weather there are several key values that we mention, such as the speed of the solar wind, particle density of electrons and protons, the strength and orientation of the IMF, and so on.
Weather on Earth varies from place to place and over time. The same is true for space weather. Space weather might be "stormy" in the vicinity of Mars while it is calm in the neighbourhood of Jupiter. A CME aimed at Earth might disrupt space weather in our neck of the woods for a day or two, but could be followed by a period of less disturbed conditions. Changes in weather, both the Earth and space varieties, take place over a wide range of time scales. Some changes happen in matters of minutes and hours, others take days or weeks, and some span periods of years or longer.
Because heat from the Sun is the primary driver of weather on Earth, you might suspect that space weather has a strong influence on Earthly weather. Scientists believe that this is likely, but convincing evidence in support of this assumption has been difficult to come by. Although the Sun's brightness varies over the course of the 11-year sunspot cycle, the variation of output in the visible portion of the spectrum from the highest to the lowest point in the cycle is a slight 1/10th of one percent. However, there have been periods of extreme weather, such as a severe cold snap in the 1800's, that correspond with unusual periods in the solar cycle.
Temperature in outer space depends on many factors: distance from a star or other cosmic event, whether a point in space is in direct light or shade and if it is subject to a solar flare or solar wind. Variation in the temperature of space near the Earth is primarily based on location and time: Temperatures are drastically different on the light and shaded sides of the planet, which gradually change minute to minute based on the planet's rotation on its axis and its revolution around the sun.
Absolute Zero
The key defining characteristic of outer space is emptiness. Matter in space concentrates into astronomical bodies. The space between these bodies is truly empty - a near-vacuum where individual atoms may be many miles apart. Heat is the transfer of energy from atom to atom. Under outer space conditions, almost no energy is transferred because of the vast distances involved. The average temperature of empty space between celestial bodies is calculated at 3 kelvins (minus 270.15 degrees Celsius or minus 457.87 degrees Fahrenheit). Absolute zero, the temperature at which absolutely all activity stops, is zero kelvins (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit).
When we describe weather on Earth, we talk about several interrelated factors such as temperature, wind speed and direction, humidity, precipitation, barometric pressure, cloud cover, and so on. Similarly, when we speak of space weather there are several key values that we mention, such as the speed of the solar wind, particle density of electrons and protons, the strength and orientation of the IMF, and so on.
Weather on Earth varies from place to place and over time. The same is true for space weather. Space weather might be "stormy" in the vicinity of Mars while it is calm in the neighbourhood of Jupiter. A CME aimed at Earth might disrupt space weather in our neck of the woods for a day or two, but could be followed by a period of less disturbed conditions. Changes in weather, both the Earth and space varieties, take place over a wide range of time scales. Some changes happen in matters of minutes and hours, others take days or weeks, and some span periods of years or longer.
Because heat from the Sun is the primary driver of weather on Earth, you might suspect that space weather has a strong influence on Earthly weather. Scientists believe that this is likely, but convincing evidence in support of this assumption has been difficult to come by. Although the Sun's brightness varies over the course of the 11-year sunspot cycle, the variation of output in the visible portion of the spectrum from the highest to the lowest point in the cycle is a slight 1/10th of one percent. However, there have been periods of extreme weather, such as a severe cold snap in the 1800's, that correspond with unusual periods in the solar cycle.
Temperature in outer space depends on many factors: distance from a star or other cosmic event, whether a point in space is in direct light or shade and if it is subject to a solar flare or solar wind. Variation in the temperature of space near the Earth is primarily based on location and time: Temperatures are drastically different on the light and shaded sides of the planet, which gradually change minute to minute based on the planet's rotation on its axis and its revolution around the sun.
Absolute Zero
The key defining characteristic of outer space is emptiness. Matter in space concentrates into astronomical bodies. The space between these bodies is truly empty - a near-vacuum where individual atoms may be many miles apart. Heat is the transfer of energy from atom to atom. Under outer space conditions, almost no energy is transferred because of the vast distances involved. The average temperature of empty space between celestial bodies is calculated at 3 kelvins (minus 270.15 degrees Celsius or minus 457.87 degrees Fahrenheit). Absolute zero, the temperature at which absolutely all activity stops, is zero kelvins (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit).
