Ever since life began, people have been dreaming about going to space someday. In the recent past, that dream became a reality during the “Space race” which began in shortly after WW2 with a conflict between Russia and the U.S also, known as the cold war. Each side attempted to prove the superiority of their technology, military fire power and political system. Multiple years after the start of the cold war, Space was thrown into the mix. Russia and the U.S then began the space race on October 4th, 1957. Russia launched a soviet R-7 intercontinental ballistic missile, which launched the Sputnik satellite. This was the first Satellite to enter earth’s orbit. Fast forward a few more years and President Dwight Eisenhower signed a public order which created NASA. The National Aeronautics and Space Administration. During this time the space race began to heat up and in 1959 the soviets launched the Luna 2 which was the first probe to reach the moon. 2 years later, the Soviets became the first country to put a person into earth’s orbit.
The American’s began testing their own crafts with chimpanzees. In May 1961, President Kennedy made a BOLD public announcement that we would get a human to the moon before the end of the decade. In February the following year, John Glenn became the first American to reach the orbit of the earth. 8 year later astronauts: Neil Armstrong, Edwin “Buzz” Aldrin, and Michael Colins set off from earth on the Famous Apollo 11 mission. It was a successful mission and the U.S finished the space race with the first humans on earth to land on the moon. This solidified the space race against the Soviets.
Ever since the space race was over, the whole “humans in space” thing kind of died down. That doesn’t mean unmanned space mission stopped. Once we made it to the moon, we have been eager to discover other planets. The U.S started small by uncovering more planets and moons in our solar system but soon started to discover a new classification of plants called “Exoplanets.” An Exoplanet is defined as: “Any planet beyond our solar system.” The first signs of Exoplanets was in 1995 when NASA began using a satellite to discover a Sun-like star. Instead, they saw what seemed to be a planet. This made NASA more eager about exploring our universe. 16 years later, NASA confirmed the first official terrestrial Exoplanet, named Kepler-10b. It was named that because it was discovered by the Kepler Space Telescope. Ever since the Kepler Telescope had discovered the first terrestrial planet outside our solar system in 2011, Over 1000 other planets have been discovered using the Kepler, Hubble, and Spitzer Space Telescopes.
A statistical estimation says that there is at least one planet per star, putting around a trillion planets in our Galaxy alone. This means there are at least a million if not a billion habitable planets in our galaxy. A habitable planet is defined as: A Habitable planet must be in a “Habitable Zone” which means it is at a range of distance from a star where liquid water might pool on the planet’s surface. To find similar planets to Earth, Astronomers are focusing on the ‘habitable zones’ around different stars, where it’s not too hot nor too cold for liquid water to exist on the surface. With the discovery of the planet Kepler-186f NASA confirms that Earth-Size planets exist in habitable zones. “If we can identify another Earth-like planet, it comes full circle, from thinking that everything revolves around our planets to knowing that there are lots of other Earths out there.” -Sara Seager, Professor of Planetary Science and Physics at MIT
It has been about 20 years since the Ground and Space-based observations began and about 3200 different Exoplanets have been discovered. “If we find lots of planets like our…we’ll know its likely that we aren’t alone, and that someday we might be able to join other intelligent life in the universe.” -William Borucki, Principle Investigator for NASA’s Kepler Mission. NASA’s ultimate goal of the Exoplanet program is to find unmistakable signs of current life. With that goal in mind the WFIRST Telescope, or the Wide-Field Infrared Survey Telescope will launch in the mid 2020’s. The telescope could zero in on a distant planet’s reflected light to detect the signatures of oxygen, water vapor, or some powerful indication of possible life.
Exoplanet Terms Sometimes the terms used to describe the planets beyond our solar system need more explanation. Below are some of the more common phrases you will hear. “Hot Jupiter’s” are Star-Hugging, infernal worlds. “Super Earths” are super mysterious, frozen planets, gas giants make Jupiter look puny or small, rocky planets in Earth size range but in tight orbits around Red Dwarf Stars. A “Water-World” is a hypothesized extrasolar planet with surfaces completely covered by deep oceans. Exoplanet: A planet orbiting a star other than our sun; also called an “Extrasolar Planet” Habitable zone: The range of orbital distance from a star at which temperatures would allow liquid water to pool on the surface with sufficient atmosphere. Goldilocks zone: Another name for habitable zone because the zone is “Just Right”
Terrestrial planets: Planets composed mostly of rock and metals, like Earth, Venus, Mars, and Mercury. Sometimes also called “rocky” or “telluric.” Tidally locked: When a celestial body, such as a planet or moon, always has one side facing the body it orbits, such as a star or planet. A Tidally-locked planet has a day side facing the heat of its Star, and a colder night side facing away. Tidal forces and the stars gravity “lock” the planet, so that its orbital period is equal to its rotation period. Red Dwarf star or M Dwarf star: A class of small, relatively cool star, emitting dim, red light. They are the most common type of star, comprising about 75% of all stars in the galaxy. Light-year: The distance light travels in one year, 5.88 Trillion miles (About 9.5 Trillion Kilometers) AU: An astronomical unit-the distance between Earth and the Sun, or about 93 Million miles (150 million Kilometers) Super-Earth: One of the most common types of Exoplanets discovered so far, with a mass between that of Earth and Neptune. The properties of such planets are largely unknown.
Orbit: The curving, repeating path of an object, such as a satellite, moon or planet, around a space body such as a moon, planet or star. Infrared: Electromagnetic radiation with wavelengths longer than the red end of the visible light spectrum, but shorter than microwaves. James Webb Space Telescope: This future NASA space Telescope, scheduled for launch in 2021, will be a large infrared telescope with a 6.5-meter primary mirror. It is sometimes called JWST or WEBB. Spitzer Space Telescope: A NASA space telescope launched in August 2003, currently in an Earth-Trailing orbit. Spitzer observes infrared radiation from exoplanets, stars, stellar nurseries, the center of the galaxies and the early stages of planetary system formation. The mission ended Jan. 20, 2020. Light curve: Graphical representation of changes in the brightness of space objects over time, including those of variable stars, supernovae and transiting Exoplanets that sometimes pass in front of their stars.
Hot Jupiter: A giant, gas planet in extremely close orbit around its star. Some complete a single orbit-their “Year” is as little as a few Earth days. Radial Velocity: The amount of “Wobble” induced in a star by the gravity of an orbiting planet, or planets. By measuring the stretching and compressing of light wavelengths from the star, as it is pulled in one direction, then another, Earthbound observers can detect Extrasolar Planets. Brown Dwarf: A Star-Like object that is not quite massive enough to burn like a star, but bigger that a planet. Ultra-Cool Dwarf: Star-like objects with effective temperatures of less than 2,700 Kelvin are referred to as “Ultracool Dwarfs.” This group includes stars with extremely low mass and brown dwarfs, or objects that are not quite massive enough to burn like a star. “Dwarf” is the term for an average adult Star, used to distinguish star like the sun from the giant star that exists in the Universe.
The mass of a planet is the amount of matter in the planet, which is not always the same as its “size.” Exoplanet masses are measured in comparison to Earth for smaller rocky planets, or Jupiter for big gas planets. The standard unit of mass is the kilogram (kg), and the Earths mass is about 5.97 x 10^24 Kg. Spectroscopy: A method of analyzing light by separating it into distinct wavelengths, which allows to identify its chemical components to determine the atmospheric components of alien worlds. A dim, compact star; The remnant core that remains after intermediate-mass stars exhaust their nuclear fuel and blow off their outer layers. They are dominated by oxygen and carbon, but often have thin layers of hydrogen and helium. F-type star: A main sequence star that is somewhat hotter more massive, and more luminous than our Sun.
To find signs of life on distant worlds, scientists must stare across vast gulfs of space, seeking the firefly light of tiny planets amid the searchlight glare of their parent stars. Especially in this new era of exploration, the technological challenges are immense. With this new era, all technology is highly advanced to do specific jobs up in space like finding Exoplanets and discovering new things about the universe. An example of this highly advanced technology is a satellite built by NASA engineers and astrophysicists. It is a gigantic mechanical sunflower the size of a baseball diamond, called the star shade, which would unfold its petals in space to block the light of target stars while using methods to find Exoplanets. When it comes to telescopes and satellites. Bigger is definitely better. One of NASA’s main Exoplanet satellites which is called “TESS” Transiting Exoplanet Survey Satellite is a relatively small satellite, but it does have a big job in finding Exoplanets.
