The Wide Field Infrared Survey Telescope (WFIRST)

WFIRST, which stands for Wide Field InfraRed Survey Telescope, is NASA’s observatory that is designed to research the area of dark energy, exoplanets, as well as infrared astrophysics for six years.

WFIRST’s primary mirror is 2.4 meters, which is 7.9 feet, in diameter. This size is the same as the size of Hubble Space Telescope’s primary mirror. These two telescopes also have the same structure. WFIRST has two instruments, the Wide Field Instrument, and the Coronagraph Instrument. The Wide Field Instrument has a field of view that is 100 times greater than the Hubble infrared instrument, and it is able to capture more of the sky by using less of the observing time.

The Wide Field Instrument, which is the primary instrument, will measure light from a billion galaxies over the course of the mission lifetime. It will also perform a microlensing survey of the inner Milky Way to find approximately 2,600 exoplanets. On the other hand, the Coronagraph Instrument will perform high contrast imaging and spectroscopy of dozens of individual nearby exoplanets.

 

Picture from Newton

 

What Is Hyperthermophile

Hyperthermophile is an organism that is able to live and thrive at high temperatures, compared to the suitable environment for survival for most of the lives on Earth. For example, a hyperthermophile can handle a temperature above 80°C, which is 176-degree Fahrenheit. The first identified hyperthermophile is Sulfolobus acidocaldarius, which is both a hyperthermophile and an acidophile. It was discovered in the late 1960s in a hot, acidic spring in Yellowstone National Park.

Hyperthermophile is one of the three types of thermophiles. The other two types are the obligate thermophiles and the facultative thermophiles. The obligate thermophile is unable to survive at relatively lower temperatures, whereas the facultative thermophile is able to survive and even thrive at a relatively low temperature. On the contrary, hyperthermophile likes high temperatures, usually above 80 °C and this range is appropriate for its growth.

 

Picture from National Park Service

 

 

Some Interesting Facts about Uranus

Uranus is one of the gas giants in our solar system. Unlike most of the objects in our solar system, Uranus is rotating in an opposite direction, which means it is rotating clockwise if viewed from Earth’s north pole. However, this is not a unique feature. In fact, Venus does this as well.

Uranus’s tile is about 97 degrees, meaning it is rotating on its side. It is indeed the largest tilt of any planet in our Solar System. This also means that the seasons on Uranus are very long and the difference between seasons are at extreme. According to NASA, ror nearly a quarter of each Uranian year, the Sun shines directly over each pole, plunging the other half of the planet into a 21-year-long, dark winter. What’s more, the rings of Uranus are also sideways compared to the rings of other planets.

 

Picture from Metro News UK

 

Facts About Callisto

Callisto is one of Jupiter’s moons, and it is one of the four Galilean moons. Compared to Earth’s Moon, Callisto’s diameter is about 1.4 times that of the Moon and 1.5 times in mass. The distance between its parent planet, Jupiter, and Callisto is about 5 times the distance between Earth and our Moon.

From what astronomers can tell, the surface of Callisto looks featureless compared to other Galilean moons. Its surface has many craters, indicating a very old surface and there is hardly geological activity. It is thought that the surface is billions of years old.

However, compared to the Moon, what is different on Callisto is that it has an extremely thin atmosphere and a possible underground ocean. Its atmosphere consists of mostly carbon dioxide. According to NASA, its atmosphere is so thin that it is easily lost due to the Sun’s ultraviolet radiation.

The idea of possible underground ocean comes from the discovery of the magnetic field fluctuation in time with Jupiter’s rotation. The most plausible explanation for the fluctuation is that there is an underground ocean of salt water, since salt water is a reasonable conductor of electricity and that is how it affects the magnetic field and causes fluctuation.

 

Picture of Callisto Taken by Voyager 1, Smithsonian National Air and Space Mesuem

 

 

Measuring the Interior of the Earth

It is very hard to drill to the deepest part of the Earth. However, there are some indirect measurements that allow us to know limited information about the interior structure of the Earth. One of those is the measurement of seismic waves.

By knowing the characteristic of seismic waves, we are able to identify the properties of the material that the waves pass through since different types of material affect the speed of the waves by different amount. Then, the precise measurement is based on the duration that certain seismic waves travel after an earthquake, indicating the specific properties of the materials that the waves encountered.

There are two types of seismic waves: P-waves and S-waves. P-waves are able to pass through solid and liquid materials, whereas S-waves are only able to pass through solid material. With the above information, the structure of the interior of the Earth can be calculated, which has a liquid outer core and a solid inner core.

 

Picture from Andres Robotics and Science

 

Spring tides and Neap tides

Tides happen everyday, but there are certain types of tides do not happen everyday. The strongest tides and the weakest tides are called spring tides. Spring tides happen when the Sun and Moon are aligned, causing unusually strong gravitational forces and resulting very high and very low tides.

Because it takes a month for the Moon to orbit Earth once, there are two chances for spring tides to happen in each month, meaning that they occur during the full moon and the new moon.

Neap tides are weak tides, which show the weakest tidal effect. They happen when the gravitational forces of the Moon and the Sun are perpendicular to one another, causing the bulges to conflict each other and then partly cancel the tidal effect. Neap tides happen when the Moon is at first or third quarter.

Picture from NOAA’s National Ocean Service

 

How do radio waves differ from visible light

Radio waves actually travel at the speed of light in vacuum, which is about 300,000,000 meters per second. It is fast enough for anyone on Earth to contact others on Earth in less a second. Radio waves are electromagnetic waves, so is light. The differences between light and radio waves are their frequencies and wavelengths.

Wavelengths with different sizes also have slightly different properties. For example,  radio waves have a longer wavelength and lower frequencies, so they are less energetic than visible light and that is why radio waves have relatively no effects on human body.

It is also because of their differences in frequencies and wavelengths, radio waves can pass through certain materials that visible light can not. However, when light encounters a thick and opaque material, it is likely to be reflected or absorbed. That is why, people can use cellular services inside buildings but can not do so in elevators.

 

Picture from Gilnahirk Action Group

 

Historical Astronomers in Context

Johannes Kepler (December 27, 1571- November 15, 1630), summarized his discoveries with three physical principles. First, the planets move in elliptical orbits, but not perfect circles, with the Sun at one focus. Second, he argued that the time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and that arc. Third, there is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits. These principles, later became laws, improved Copernicus’s solar system and helped to explain some astronomical phenomena.

When Kepler was alive, France’s King Henry IV converted from Protestantism to Roman Catholicism. Henry IV of France, a progressive king who is religiously tolerant, is assassinated by François Ravaillac, who is unbalanced and highly religious.Also, Sweden joined the Thirty Year’s War. The Swedes invade northern Germany and won multiple bateles and finally had decisive victory. Elizabeth I (September 7 1533 – March 24 1603), was also alive at the same time as Kepler, was undisputedly one of the greatest monarchs of England who ruled the country from 1558 to 1603. Popularly known as the Virgin Queen, her 45 years of reign marked a glorious epoch in English history.

It is obvious to notice that scientists were slowed down by limited technology. It took decades and generations for people to develop technology and to discover the universe with limited technology. Also because of this slow process, the world did not improve much and the big events that were happening were mostly wars. It is glad to see that later scientist solidified Kepler’s three laws and facilitated the learning of the universe at that time.

Some facts about the speed of light

The speed of light is 299,792,458 meters per second (186,282 miles per second), but this is not always the case. The speed of light, which is actually the highest speed that light can reach, has to be in a vacuum.  In other cases, light actually slows down as it passes through different media. For instance, when light passes through glass, it slows down to about two-thirds of its speed in a vacuum. Even in air, which is nearly a vacuum, light slows down slightly.

In the picture,  the laser shining through a glass of water demonstrates how many changes in speed it undergoes as it passes from air, to glass, to water, and back again.

 

Picture from Universe Today

 

A picture

 

Picture from WordPress.

 

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