What type of celestial body left over from the formation of our own solar system, is made up of silicate materials and metals and is smaller than a planet?
asteroid
Hundreds of thousands of asteroids are located in the “asteroid belt,” a region of space between Mars and Jupiter.
The largest asteroids are almost 600 miles (965 km) in diameter.
What landmark historical event occurred on July 20, 1969?
The first humans set foot on the moon
Three Americans were on this mission aboard Apollo 11: Neil Armstrong, Buzz Aldrin, and Michael Collins.
Armstrong became the first man to walk on the moon, and made the iconic statement: “That’s one small step for man, one giant leap for mankind.”
What celestial body releases gas or dust and is made of ice and other materials left over from the Big Bang?
comet
Comets (as seen from Earth) are characterized by a long train of gas. As they near the Sun, its radiation warms their enveloping ice, causing it to sublime into gas and trail behind them.
It is theorized that some of the organic compounds that make up our water and made early life possible traveled to Earth by comet.
What was the first satellite launched by humans on October 4, 1957?
Sputnik (I)
The satellite was launched by Russia and traveled for 92 days in space before burning up in the atmosphere upon its return.
Sputnik has historical significance, as it led to the Space Race between the United States and Russia in a time where tensions were already high as a result of the Cold War.
What event, believed to have occurred 13.8 billion years ago, may mark the inception of our universe?
The Big Bang
The universe started in a small, dense, and hot state, then began expanding and cooling.
Evidence for the Big Bang is found in the form of Cosmic Microwave Background radiation.
Which 20th-century American scientist and author gained widespread popularity for his 1980 television series Cosmos: A Personal Voyage, and its accompanying book by the same name?
Carl Sagan
(1934-1996)
Sagan was a celebrated astronomy researcher who studied the surface temperatures of Venus and the possibility of extraterrestrial life.
Which 16th- and 17th-century Italian physicist and philosopher proved that objects with different masses fall at the same velocity, and also discovered the moons of Jupiter?
Galileo Galilei
Galileo was a central figure in the Scientific Revolution and an early supporter of heliocentrism, in which the sun is the center of the solar system and the planets revolve around it.
Galileo also made improvements to the design of the telescope and laid the groundwork for modern kinetics, dynamics, and astronomy.
Which Greek-Roman philosopher is the creator of the Ptolemaic model of the universe, which had Earth at its center, and which persisted for nearly two millenia?
Claudius Ptolemy
(90 A.D. - 168 A.D.)
What are stars made out of?
mostly of hydrogen and helium
Stars produce their own light and energy through nuclear fusion.
As stars reach the end of their life, having burned through their volume of hydrogen, they begin to cool and burn red instead of white. The largest red stars are called red supergiants (1000 times larger than our sun), while the smallest are called red dwarves (1/10th the size of our sun)
Neutron stars are stars that have collapsed upon themselves into a superdense spinning structure consisting almost entirely of atom nuclei, one teaspoon of which would theoretically weigh 4 billion tons!
Black holes are even denser than neutron stars—the remnants of large collapsed stars—that are so dense, not even light can escape their powerful gravitational pull.
Which 15th- and 16th-century Renaissance Polish astronomer argued that the Earth revolves around the Sun, displacing the Earth from the center of the universe?
Nicolaus Copernicus
Copernicus was one of the most prominent scientists of the time to support this belief about the movement of celestial bodies.
As a result of his findings, many abandoned the Aristotelian idea that there existed no empty space between planetary spheres.
At what altitude above Earth’s surface does Space officially start?
62 miles
The Kármán Line is an imaginary boundary 62 miles (100 km) above sea level, which marks the end of Earth’s atmosphere and the start of Space.
What are the four inner “terrestrial” planets of our solar system?
(In order of distance from the sun)
- Mercury
- Venus
- Earth
- Mars
The “terrestrial” planets have compact, rocky surfaces (like Earth) and a relatively thin layer of atmosphere.
The exception is Mercury, which is so small its gravitation isn’t enough to attract an atmosphere.
What are the four outer “gas giants” (planets) of our solar system?
(In order of distance from the sun)
- Jupiter
- Saturn
- Uranus
- Neptune
The “gas giants” are separated from the four inner “terrestrial” planets by an asteroid belt.
They are made predominantly of elements like hydrogen, helium, ammonia, and methane in both gas and liquid form.
They do not have a clearly-defined rocky surface.
What is the largest planet in our solar system?
Jupiter
Jupiter weighs more than 2.5 times that of all the other planets in the Solar System combined.
If Earth were the size of a nickel, Jupiter would be about as big as a basketball.
What is the smallest planet in our solar system?
Mercury
Mercury is only slightly larger than Earth’s moon.
In fact, it’s so small, its gravitation isn’t enough to hold a layer of gas close to the planet, leaving it without an atmosphere; although, even if it did have one, it’s proximity to the sun would instantly blast it away.
What is our nearest neighboring galaxy?
the Andromeda Galaxy
If you could travel at the speed of light, it would still take you 2.5 million years to get to the Andromda Galaxy; and yet it is our closest galaxy!
This is testament to the incredible size of Space.
What do astronomers call stars that die in a powerful explosion?
supernovas
When stars run out of fuel to burn, they implode inwards to a single superdense and superheated center.
Then, if the star is massive enough, the intensity of pressure causes a catastrophic explosion that sends vast plumes of light and matter out into space.
What is the term for a large, dead star that is so dense, not even light can escape its gravitational pull?
black hole
When large stars collapse, they become so massive and dense that their gravitational pull even sucks light into it, making it appear in our telescopes as total blackness of space.
There are four types of black holes: stellar, intermediate, supermassive, and miniature. The most commonly known way a black hole forms is by stellar death.
Which well-known star is formally called Polaris and can be found in the Ursa Minor (Little Bear) constellation?
North Star
The North Star sits more or less directly above Earth’s north pole, which means you can use it to orientate yourself should you ever get lost.
What is the brightest star in our night sky?
Sirius
Sirius belongs to the Canopus Major (“Large Dog”) constellation.
While planets like Jupiter, Saturn, and Venus appear quite a bit brighter in the night sky, they are not stars.
Stars produce their own energy by burning gas and therefore appear to flicker and twinkle. Planets reflect sunlight and so they appear to glow steadily. This is how you can tell the difference!
So, once again, while Jupiter, Saturn, and Venus look many times brighter than Sirius, Sirius remains the brightest STAR in the night sky!
How long does it take the sun’s rays to reach Earth?
8 min, 20 sec
The light you’re seeing from that burning orb in the sky actually left the sun 8 minutes and 20 seconds ago. So, in reality, the sun sets just over 8 minutes before you see its light disappear beneath the horizon.
For stars that are further away, this delay gets even more interesting. Light from our nearest star, Proxima Centauri, takes 4.3 YEARS to reach Earth. I.e. the twinkling light you see in the night sky left the star 4.3 years ago.
For stars that are even further away, you are truly looking at ancient light! In many cases, those stars have already died but they continue to shine on in our night sky because of how long it takes their light to reach us!
What is the term for bits of space debris that burn up in the Earth’s atmosphere, appearing to us as bright streaks of light?
meteors
(AKA shooting stars)
Meteorites are also bits of space debris that have entered our Earth’s atmosphere, but they are large enough to survive the journey and make contact with the surface.
What were the first living creatures intentionally sent into space?
fruit flies
In 1947, fruit flies were launched in an unnamed rocket 67 miles into the air before parachuting back to Earth. The fact that they survived the journey paved the way for human exploration.
In 1949, a rhesus monkey called Albert II became the first primate and first mammal in space.
In 1957, a dog named Laika became the first animal to make an orbital spaceflight around the Earth (aboard the Soviet spacecraft Sputnik 2).
What are we seeing when we look up at the concentrated band of stars that stretches across the sky at night?
the Milky Way Galaxy
We are looking, edge-on, down the spiral arm of the galaxy in which our solar system resides. Cool huh?
