The Habitable Zone outside Earth Essay

With all our knowledge of everything around us, overwhelming as it may be, there are still a lot of aspects that are unknown to even the smartest scientists. Did you know that humans know only 5% of the entire universe? Yes, everything we know about the Earth, the Milky Way, and all the planets is barely even a fourth of what comprises the entirety of the universe. Knowing that, it would be illogical to say that the creatures on Earth are the only forms of life in the universe. Today I will tell you about unidentified object sightings, close

A red dwarf star’s HZ, for example, would be much closer to the star itself compared with that of our sun. It is also important to determine the planet’s size and mass, which is imperative in deciding whether it can sustain an atmosphere. Maintaining an atmosphere is essential for life to exist and small a planet with a small gravitational force at its surface may not be capable of retaining one. The Kepler transit data can only measure planet masses, diameters, orbital periods, and parent star types and although this information is useful for determining habitable zones, further data is required to determine true habitability. The latter can be done by studying the composition of the exoplanet’s atmosphere.

Aliens and life beyond earth has been a mystery for a long time. Many people and scientist have been looking for life outside of Earth, or just floating in the sky trying to get video of it. For all of human history we have been looking for extraterrestrial life, and these are the major events of finding, debunking, and moving forward to life on earth

Atmospheric carbon impacts the temperature of the Earth because it is a greenhouse gas. When visible light from the sun heats the surface of the earth, some of the energy is transmitted back towards the

Among the billions of stars in each galaxy, many have planets that revolve around them. At least a few are bound to be of the right size and have the correct spatial orientation with respect to their star to allow life to grow. We believe this because life exists on the Earth. Astronomers have concluded that there must be hundreds of billions of other stars with conditions approximating those of the sun. Therefore there could be a million earth like planets with advanced civilizations in the Milky Way galaxy alone (Stilley). It is very probable that there is intelligent life elsewhere in the universe.

All the habitable zone estimates assumes that these planets have an atmosphere. The exoplanet must accrete enough volatiles during formation to create an atmosphere and must be massive enough to sustain the atmosphere. The atmosphere also needs to be dense enough to stabilize surface temperature through climate feedback, such as the greenhouse effect. The atmosphere should absorb in the infrared spectrum but not in the visual

The radial velocity method was used to detect the first exoplanet, 51 Pegasi b (51 Peg b) around a main sequence star, 51 Pegasi (51 Peg). The radial velocity method uses the variations in velocity of a star due to the gravitational pull from an exoplanet (Lissauer 2002). Furthermore the velocity isn’t measured in terms of actual speed but in terms of light based on the Doppler effect. The Doppler effect occurs when a star moves. When it moves toward us, its wavelengths of light are shortened and when a star moves away from us, its wavelengths of light are lengthened. Through the continued observation of the Doppler effect on a stars spectrum of light, the velocity of a star is inferred. Any change in a stars velocity is caused by a sufficiently massive companion, an exoplanet (Lissaeur 2002).

The second main “driver” of global temperature change is reflectivity. Changes in reflectivity affect how much energy enter Earth’s system. When the sunlight reaches Earth, it can be reflected or absorbed, and that depends on the Earth’s surface and atmosphere; light colors reflect the most sunlight, while dark colors absorb more sunlight. Albedo, the amount of solar radiation reflected from an object or surface, indicates the amount of sunlight reflected as a percentage. Earth has an albedo of about 30%, which means that 70% of the sunlight is absorbed (NRC, 2010). This is important because the sunlight absorbed warms the land, water and atmosphere. In the past, this can be seen in the melting of sea ice or increases in cloud cover.

Greenhouse gases ,such as carbon dioxide, is absorb and emits heat into the earths atmosphere, keeping the Earth warm enough to support life. However, human activities, such as burning fossil fuels, are adding large amounts of greenhouse gases to the atmosphere. Earth must get rid of energy at the same rate it receives energy. More greenhouse gases means that more heat is being held in the atmosphere, which makes the temperatures higher. All the greenhouse gases people have added to the

The argument suggesting life existing on other Earth-like planets has been present since man first looked into space and questioned his own existence and the existence of others like him. Today there are many theories on the existence of intelligent life elsewhere in the universe, but only one theory goes beyond them and into an even larger realm. The contents of this theory, known as the “multiverse” theory, suggest that humans on Earth live within one universe of many others that reside within a primordial vacuum containing many other universes (Jenkins and Perez). Each of these universes possesses potentially different natural constants and physical laws that govern them differently, thus calling forth some logical questions. First,

Many people who live on Earth are close minded to what is really out there in the universe. They cannot even begin to fathom the vastness of it and how Earth is just a tiny little speck compared to everything else out there. From the planets to the stars and out towards the edge of the unknown, we can only see what science provides us with. From this, we know that we are nothing but a tiny planet located in a solar system of millions in a galaxy of many more in the universe.

The primary cause of climate change is the human expansion of the greenhouse effect. The greenhouse effect is a natural occurrence, which NASA defines as “the warming that results when the atmosphere traps heat radiating from space” (NASA). During the greenhouse effect, heat from the sun passes through the atmosphere, which is made up of various gases. When the heat from the sun reaches the surface, some of it radiates away from Earth, back into space. However, some of the gases in the atmosphere, known as greenhouse gases, absorb this heat, preventing it from escaping (World Meteorological Organization). The greenhouse effect keeps the Earth at a habitable temperature. The World Meteorological Organization, or WMO, states that the greenhouse effect and

Energy from the sun drives the earth’’s weather and climate, and heats the earth’’s surface; in turn, the earth radiates energy back into space. Atmospheric greenhouse gases (water vapor, carbon dioxide, and other gases) trap some of the

Personally, the idea of either being alone in our galaxy or not alone in our galaxy gives me the chills. Our place in the Universe is undefined because of our lack of knowledge and insight. As of now, life on Earth is the only known intelligent life, but there are hypotheses and theories that suggest otherwise. I believe that the probability of life in our galaxy is high and that we have a high probability of finding it.

Any factor that alters the amount of radiation received from the sun or heat lost to space may influence the climate. Therefore, any enhancement of the Greenhouse effect is a cause for concern. Besides fluctuations of solar radiation due to the earth orbiting around the sun, human activities influence the number of greenhouse gases.