TELESCOPES:

• A telescope is an optical instrument designed to make distant objects appear nearer and brighter.


• Muggle astronomers have utilised telescopes to discover new asteroids, planets, comets, stars and galaxies, and moons. Uranus, Neptune, and Pluto are planets that were discovered through the use of telescopes.

HISTORICAL TIMELINE:

• The first developed telescopes had two individual lenses at opposite sides of a tube. A light-gathering convex lens (a positive lens) was placed at the far end, while a concave eyepiece (a negative lens) was placed at the near end. Two lenses were required due to the fact that a convex lens tends to make objects appear blurry. This was a Muggle telescope invented by Hans Lippershey in 1608, and made distant objects look three times larger as if they were to be viewed with the naked eye.


• In 1610, Galileo Galilei discovered that the magnifying power of this telescope could be increased to 20 by decreasing the curve in the objective lens. This was then used to identify Jupiter's four largest moons, now known as the Galilean moons. Galilei also discovered that Venus has similar phases to the Moon, furthermore confirming that the Earth revolves around the sun. Any telescope with a concave eyepiece is now called a Galilean telescope.


• Despite this evolutionary discovery, it meant that the telescope had a highly miniscule field of view. In 1611, Johannes Kepler discovered that if the eyepiece was switched to a convex lens, the field of view would be increased (although everything would appear upside down). This type of telescope is known as an astronomical telescope.


• At the beginning of the 17th century, the terrestrial telescope was formed through the use of two convex lenses, meaning that the telescope would not present the view upside down.


• All three of the mentioned telescopes have been improved and adjusted over the years, enabling the ability to change the focus. Additionally, newer models have been designed to support two individual tubes (a wider tube for the objective lens and a narrower tube for the eyepiece).


• During the 17th century, refracting telescopes caused distorted colours to appear at the edge of the field of view due to the way in which light refracts differently there. In 1688, Isaac Newton solved this problem by replacing the lenses with mirrors, inventing the reflecting telescope. Any telescope taking the form of this design is now called a Newtonian telescope.


• In 1929, Edwin Hubble used the biggest telescope ever created (the 100-inch-wide Hooker telescope) to conclude that the universe is constantly expanding, initiating the branch of astronomy known as cosmology.

MAGNIFICATION:

• A telescope's power refers to the amount by which a distant object is magnified through one's utilisation.


• This magnification can be increased in a telescope by weakening the objective lens or mirror and strengthening the eyepiece.


• A telescope can gather more light with a larger objective lens or mirror.


• For example, making the objective lens or mirror of a telescope twice as wide and twice as long will gather four times as much light, since two times two is equal to four.


• Additionally, making an objective lens or mirror larger also improves the resolution of a telescope. The naked eye has the ability to identify two points of light about 1/20th of a degree apart, while astronomers are required to distinguish distant objects with an even smaller observed distance. 


• These miniscule fractions of a degree are instead measured in arcminutes and arcseconds. A single degree is divided into 60 arcminutes and 1200 arcseconds.


• Doubling the diameter of the objective lens or mirror of a telescope will result in a doubled resolution. However, this can be negatively impacted by the air due to its movement, as this causes the stars to appear to be constantly moving. This makes it highly challenging to achieve a resolution better than one arcsecond, despite the size of the telescope.


• Nowadays, large telescopes utilise adaptive optics to solve to this problem, in which the mirror contorts hundreds of times each second in an effort to compensate for the observed movement of the stars. Another solution involves launching a telescope into orbit to limit the air interfering with the stars' appearance.

SATELLITES:

• A satellite is an object that is orbiting a planet. Moons are an example of natural satellites, while artificial satellites consist of human-made objects that are purposely launched into object through the use of rockets.


• While Muggles utilise satellites to conduct GPS's, satellites can additionally be used for communication, to review and photograph the Earth, to study weather conditions, and to place telescopes above the atmosphere.


• The Hubble Space Telescope is a telescope that is currently in orbit around the Earth, and is around 2.5 metres in width. This means that this telescope should have the ability to resolve two individual stars that are 0.05 arcseconds apart.


• In 1990, this telescope held a resolution of more than one arcsecond, caused by a flaw in the primary mirror, sending back unclear images. This problem was resolved three years later, after a team of trained astronauts improved the resolution to the expectation.


• After this correction, the Hubble Space Telescope assisted in identifying distant black holes and galaxies, more accurately estimating the age of the universe, and improving accuracy rates regarding its expansion, proving that this is accelerating.


• In addition, satellites carry numerous other important tools that conduct a variety of uses.


• Satellites have been placed in the orbit of various other celestial bodies, including all planets, a selection of their moons, and a few comets and asteroids.
  

THE SPACE RACE:

• In 1957, the Soviet Union launched the first satellite (Sputnik).


• Four months in advance, the United States also successfully launched a satellite (Explorer 1) after numerous failures.


• This was after a second satellite was launched by the Soviet Union, this time carrying a dog. 


• Following this occurrence, the Soviet Union launched a third satellite transporting the first man (Yuri Gagarin) into space.


• In 1958, the United States developed NASA and largely increased university fundings in order to ensure the advancement of future rocket scientists.


• Eventually, the space race was won by the United States when Neil Armstrong and Buzz Aldrin were safely transported to and from the Moon in 1969.


• However, the Soviet Union launched the first woman (Valentina Tereshkova) into space in 1963. Tereshkova spent almost three days in outer space before being safely transported back to the Earth.


• Two decades passed before the United States allowed a woman (Sally Ride) to be launched into space, due to the belief that women were incapable of this journey.

SPACE AGENCIES:

• Canada, India, Japan, and China are a particular selection of the several European countries that contribute towards the European Space Agency. This contribution can be executed either amongst other countries or simply within an individual country.


• A few days into 2019, the China National Space Administration became the first to land a rocket on the far side of the Moon.


• The International Space Station was built by the Americans, Russians, Europeans, Canadians, and Japanese through cooperation.


• Witches and wizards have had the opportunity to work under cover with a selection of these space agencies. However, this does not include NASA due to the official segregation between magical people and No-Majs organised in 1790.

SPACE SHUTTLES:

• During the early 1980s, the Space Transportation System program was introduced by NASA, utilising partially or totally reusable artificial satellites.


• These space shuttles were furthermore used to launch a variety of other satellites, interplanetary probes, and the Hubble Space Telescope. These were involved in numerous research programs in orbit and participated in the development and maintenance of the International Space Station.


• Despite this extraordinary progress, the lives of 14 astronauts were taken throughout a total of two space shuttle accidents.


• In 2011, the Space Transportation System program was terminated. Since this occurrence, astronauts and supplies from the United States have been transported to and from the International Space Station through the Russian spacecraft, Soyuz.

RADARS:

• A radar is a detection system that utilises particular wave forms to identify the range, angle, or velocity of objects. Radars execute this by bouncing waves off an object and examining those that are reflected by the object.


• Radars were originally invented to detect enemy planes and missiles through the military. However, these detection systems are also utilised in regards to air and ground traffic control, locating landmarks and ships at sea, ocean surveillance, weather monitoring, geological observations, and radar astronomy.


• The Moon, a few planets, the four largest moons of Jupiter, Saturn’s rings and its biggest moon, Titan, and a selection of asteroids and comets are all astronomical objects that have been researched through radar.


• The information gathered by astronomers regarding the surface area of these features are furthermore used by witches and wizards in order to sufficiently understand their magical effects.

ROVERS:

• Rovers are specially designed vehicles that travel across the surface of a planet or moon. Some rovers have the ability to transport people, while others are programmed to be driven from the Earth or drive themselves.


• These vehicles are commonly used to collect research on planets or moons through taking pictures, atmosphere readings, or dust and rock samples.


• Rovers have only yet been placed on the Moon and Mars, the majority of which were launched by either Russia or the United States.


• A rover that is programmed to be controlled from Earth causes a delay regarding commands, since signals travel at the speed of light. This is often highly impractical.


• Rovers can be driven from the Earth if they are placed on the Moon's surface, as these signals only take 1.25 seconds to arrive at its destination. However, a rover would have to be self-driving if it is placed on Mars' surface, as these signals take between four and 24 minutes to arrive at its destination.

TERMINOLOGY:

• Cosmology includes the science of the origin and evolution of the universe.


• A convex lens refers to a lens that is thicker in the middle than at the edges and magnifies distant objects.


• In contrast, a concave lens refers to a lens that is thinner in the middle than at the edges and sharpens the view of an object.


• Refracting telescopes are telescopes that use only lenses, since lenses refract light.


• In contrast, reflecting telescopes are telescopes that use only mirrors, since mirrors reflect light.


• The term resolution is dependent on the observed distance of two points of light, while still being seen as individual points. This is measured as an angle, not a straight-line distance.