The corona is a. 300 times cooler than the surface of the Sun b. 300 times hotter than the surface of the Sun c. 300 times cooler than the surface of the Earth
On Earth, coronal mass ejections can cause a. severe storms b. extremely high temperatures c. damage to the power grid
The corona is only visible during a. a CME b. a solar flare c. a total solar eclipse
Discussion/essay questions
In 1859, a CME caused telegraph stations around the world to burn out. Because we depend so much on technology, a CME of the same size today would cause major damage. What do you think the world would be like without any modern technology?
Transcript
The outer atmosphere of the Sun is called the corona. It is a thin layer of charged gas that extends for millions of kilometres. It is actually about 300 times hotter than the Sun’s surface, which is an ongoing puzzle for scientists. The corona is a chaotic environment, and it sometimes releases large amounts of magnetic matter into space. This is called a coronal mass ejection, or CME. Scientists monitor CMEs because they can damage the power grid on Earth. Most of the time, the corona is impossible to see with the naked eye. The surface of the Sun is so bright that it completely outshines the light from the outer layers. However, the corona can be seen briefly during a total solar eclipse, when the Moon obscures the Sun from view.
Neutrinos are hard to find because a. they react with most substances b. they have no mass at all c. they rarely interact with other matter
Most of the neutrinos that reach Earth come from a. nuclear power plants b. radioactive substances c. the Sun
Neutrinos are a. the rarest type of particle in the universe b. the most common type of particle in the universe c. the second most common type of particle in the universe
Discussion/essay questions
Scientists study particles like neutrinos to find out how and why the universe formed the way it did. Do you think it is possible to fully understand what happened at the beginning of time? Why or why not?
Transcript
Neutrinos are tiny particles that are produced when atoms split, fuse, or decay. They are sometimes called “ghost particles,” because they are very difficult to detect. Neutrinos are so small that they rarely interact with other matter. Trillions of neutrinos pass through our bodies every second without touching us at all. Most of the neutrinos that reach Earth come from the Sun. They are a byproduct of nuclear fusion, which is the process the Sun uses to create energy. However, neutrinos are also produced in nuclear reactors, as well as radioactive substances. There are three types of neutrinos, and they each interact with different particles. Neutrinos can even change their type as they travel. Although they are hard to find, neutrinos are actually the second most common type of particle in the universe. They are only outnumbered by particles of light.
Joseph von Fraunhofer discovered that a. passing light through a prism would create a rainbow b. light could behave as a particle c. there were dark lines in the colour spectrum made by the Sun
Absorption lines happen when a. a cool gas absorbs photons b. a hot gas releases photons c. photons pass through empty space
Scientists can study absorption lines to find out a. the masses of stars b. the distances between stars c. the chemicals present in stars
Discussion/essay questions
Do you know any interesting facts about light? What optical illusions or “tricks of the light” have you seen?
Transcript
In 1814, a German physicist named Joseph von Fraunhofer passed light from the Sun through a prism to create a colour spectrum. He noticed that there were dark lines blocking out certain colours in the spectrum. Today, scientists call these lines absorption lines. Absorption lines happen when particles of light, called photons, move through a cool gas. The atoms and molecules in the gas absorb some of the photons and block certain colours of light. When an atom absorbs a photon, it shows up as a dark line in the colour spectrum. The photons that get absorbed are not random. Every element absorbs specific wavelengths of light, which means every element also has a unique pattern of absorption lines. Scientists can study these lines to find out which chemicals are present in stars and planets.
The inner disk of the Oort Cloud is also called a. the Hills Cloud b. the Kuiper Cloud c. the Neptunian Ring
Most of the objects in the Oort Cloud are a. asteroids b. comets c. gas planets
Sedna is the name of a. the moon that orbits Pluto b. a far dwarf planet in the inner Oort Cloud c. a comet with an orbit of millions of years
Discussion/essay questions
Some people make wishes on comets and meteors in the sky. The planets in the solar system are named after ancient gods. Why do you think humans see magic in space?
Transcript
The Oort Cloud is a cloud of small icy objects at the very outer edge of the solar system. It is thousands of astronomical units away from the Sun. It is made up of an inner disk, called the Hills Cloud, and an outer sphere, which surrounds the entire solar system. Scientists believe that the Oort Cloud formed in the early days of the solar system, when the strong gravity of the gas planets pushed other matter far away. The outer Oort Cloud contains the farthest objects that are trapped in the Sun’s gravity. Most of these objects are comets, which can take millions of years to orbit the Sun. However, the Hills Cloud also contains dwarf planets similar to Pluto. One of these dwarf planets, called Sedna, may be the farthest planet-like object in the Sun’s orbit.
The midnight sun occurs at a. the equator b. the north pole c. both the north and south poles
In the summer, the midnight sun can be seen in a. Australia b. southern Canada c. Norway
People in the north often use special curtains to a. conserve warmth b. stay dry c. mimic nighttime
Discussion/essay questions
What is the most interesting natural sight you’ve ever seen?
Transcript
The midnight sun is a phenomenon that occurs at the north and south poles. During their summer months, each region experiences 24-hour days, where the sun does not set at all. This is because of the angle of the Earth’s axis. From June until August, people can observe the midnight sun in many northern regions, such as Norway, Alaska, and northern parts of Canada. While the sun still appears to travel through the sky, it never falls below the horizon. Because there are no signals that distinguish day from night, it can be difficult to keep healthy sleep habits during the northern summer. Many people use blackout curtains to mimic nighttime.
Can you see auroras where you live? Would you ever travel to see them?
Transcript
Auroras are bright lights that appear in the sky over the North and South Poles. They are commonly known as northern and southern lights. Auroras occur when particles of plasma shoot out of the sun and collide with gases in the Earth’s atmosphere. Different types of gas can create different colours of light. Oxygen creates green light, while nitrogen creates violet light. Auroras on other planets often have different colours because of the different gases that are common in their atmospheres. On gas giants like Jupiter and Saturn, auroras are ultraviolet. Although auroras are nice to look at, they can also be dangerous. The solar particles can cause damage to technology on Earth. Scientists hope to learn more about auroras so that they can prevent possible problems in the future.
All stars die , but different stars can die in very different ways. Our Sun is a medium-sized star. That means that when the Sun dies, it will simply turn into something called a white dwarf. White dwarves are small, dense celestial objects that contain the matter left over from stars. However, some stars are much more massive than our Sun, and their deaths are much more . When a massive star gets older, it starts to cool down. This is because the star is using up the last of its . Once the star has no fuel left, it will implode. This implosion is called a supernova. The event is so bright that if a star in our galaxy caused a supernova, we could possibly see it from Earth. The force of a supernova causes the star’s mass to be compressed into a very small space with an incredibly strong gravitational pull. This is called a black hole, and it is so that nothing can escape from it.
Comprehension questions
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Discussion/essay questions
Scientists believe that over 1,000 years ago, ancient civilizations witnessed a bright supernova. Now, scientists are observing a dying star called Betelgeuse, which may go supernova soon. Do you think it’s possible that we could see a supernova in our lifetime?
Transcript
All stars die eventually, but different stars can die in very different ways. Our Sun is a medium-sized star. That means that when the Sun dies, it will simply turn into something called a white dwarf. White dwarves are small, dense celestial objects that contain the matter left over from dead stars. However, some stars are much more massive than our Sun, and their deaths are much more violent. When a massive star gets older, it starts to cool down. This is because the star is using up the last of its fuel. Once the star has no fuel left, it will implode. This implosion is called a supernova. The event is so bright that if a star in our galaxy caused a supernova, we could possibly see it from Earth. The force of a supernova causes the star’s mass to be compressed into a very small space with an incredibly strong gravitational pull. This is called a black hole, and it is so powerful that nothing can escape from it.
