Welcome to the PAC Astronomy Trivia Page!
Each day a new Trivia question, along with it’s answer, is posted to provide unique and interesting astronomical related facts.
We hope these trivia items inspire folks to learn something new and interesting everyday, while expanding their knowledge of the Universe.
If you have a special trivia item you would like posted contact the webmaster at firstname.lastname@example.org or call (928) 778-6502.
May 25, 2017 (000323)
May 24, 2017 (000322)
May 23, 2017 (000321)
May 22, 2017 (000320)
May 21, 2017 (000319)
May 20, 2017 (000318)
May 19, 2017 (000317)
May 18, 2017 (000316)
May 17, 2017 (000315)
May 16, 2017 (000314)
May 15, 2017 (000313)
May 14, 2017 (000312)
What is a Yellow Dwarf?
ANSWER: A yellow dwarf is a star and is often referred to as a G-type main sequence star. A perfect example of a yellow dwarf would be the Sun. A yellow dwarf has a mass almost like the mass of the sun. Its color ranges from white to a lighter yellow. Among the stars in the galaxy, yellow dwarf stars are bigger than most of the stars although giant stars are the biggest of all.
May 13, 2017 (000311)
What is A Planemo?
ANSWER: A planemo is a celestial object of planetary mass – one that is larger than an irregularly shaped asteroid, yet smaller than a nuclear reactive star. The term covers all bodies within this size range, although a planemo that orbits a star is more regularly referred to with the more specific term, planet. Planemo is a contraction of planetary mass object.
May 12, 2017 (000310)
What is a Magnetar?
ANSWER: A magnetar is a type of neutron star with an extremely powerful magnetic field. The magnetic field decay powers the emission of high–energy electromagnetic radiation, particularly X-rays and gamma rays.
May 11, 2017 (000309)
What is nadar?
ANSWER: The point directly below you.
May 10, 2017 (000308)
What was NASA’s first spacecraft to scan another planet?
ANSWER: Fifty-five years ago on Aug. 27, 1962, Mariner 2 was launched on a mission to scan Venus, becoming NASA’s first spacecraft to scan another planet.
May 9, 2017 (000307)
What single factor determines a star’s brightness, color, length of its life, and how it is to die?
ANSWER: It’s total mass.
May 8, 2017 (000306)
What is the largest known comet to date?
ANSWER: There are different ways to measure a comet. The Hale Bopp Comet, for example has a nucleus of more than 60 miles in diameter, which is thought to be the biggest ever encountered, so far. And Comet Hyakutake’s tail stretched out at a distance of more than 500 million km from the nucleus, the largest known. But now a group of scientists have identified a new category of measuring a comet’s size: the region of space disturbed by the comet’s presence. And for this class, first prize goes to Comet C/2006 P1 McNaught, which graced our skies in Janauary and February 2007. Of course, McNaught might win the prize for most picturesque comet, too, as this stunning image from Sebastian Deiries of ESO shows.
Dr. Geraint Jones of University College, London and his team used 2007 data from the now-inoperable Ulysses spacecraft, which was able to gauge the size of the region of space disturbed by the comet’s presence.
Ulysses encountered McNaught’s tail of ionized gas at a distance downstream of the comet’s nucleus more than 225 million kilometers. This is far beyond the spectacular dust tail that was visible from Earth in 2007.
“It was very difficult to observe Comet McNaught’s plasma tail remotely in comparison with the bright dust tail,” said Jones, “so we can’t really estimate how long it might be. What we can say is that Ulysses took just 2.5 days to traverse the shocked solar wind surrounding Comet Hyakutake, compared to an incredible 18 days in shocked wind surrounding Comet McNaught. This shows that the comet was not only spectacular from the ground; it was a truly immense obstacle to the solar wind.”
A comparison with crossing times for other comet encounters demonstrates the huge scale of Comet McNaught. The Giotto spacecraft’s encounter with Comet Grigg-Skjellerup in 1992 took less than an hour from one shock crossing to another; to cross the shocked region at Comet Halley took a few hours.
“The scale of an active comet depends on the level of outgassing rather than the size of the nucleus,” said Jones. “Comet nuclei aren’t necessarily active over their entire surfaces; what we can say is that McNaught’s level of gas production was clearly much higher than that of Hyakutake.”
Jones presented his findings at the RAS National Astronomy Meeting in Glasgow, Scotland.
May 7, 2017 (000305)
What is Hubble’s Law?
ANSWER: The law of physics that states that the farther a galaxy is from us, the faster it is moving away from us.
May 6, 2017 (000304)
What was the Cosmic String?
ANSWER: A tube-like configuration of energy that is believed to have existed in the early universe. A cosmic string would have a thickness smaller than a trillionth of an inch but its length would extend from one end of the visible universe to the other.
May 5, 2017 (000303)
Is there life on the moon today?
ANSWER: Could be! We know cockroaches can survive in space because an Apollo mission noticed one inside their space craft. When it returned, the craft was thoroughly inspected and no trace of the cockroach was found. The conclusion was that it crawled out while they were on the moon. The question is, “Did it survive?”
May 4, 2017 (000302)
What is the width of the totality path of the 2017 Solar Eclipse?
ANSWER: The path for this eclipse is projected at 60-70 miles wide. The closer you are to the center of the path, the longer totality lasts. NASA has an interactive map that allows users to receive site-specific eclipse details.
May 3, 2017 (000301)
What phenomenon causes the Moon’s rotation about it’s own axis
to be equal to the Moon’s period of revolution about the Earth?
ANSWER: Tidal Friction.
May 2, 2017 (000300)
What causes a planet to have a magnetic field?
ANSWER: The dynamo effect.
May 1, 2017 (000000299)
Why are Mercury and Venus referred to as inferior planets?
ANSWER: Because their orbits are inside the Earth’s orbit.
April 30, 2017 (000298)
Whereas latitude and longitude are the coordinates of places on earth, what are the two coordinates used for star locations?
ANSWER: Right ascension and Declination.
April 29, 2017 (000297)
What is the name given to the configuration when three celestial bodies are in a line?
April 28, 2017 (000296)
Who wrote the book “On the Revolutions of the Heavenly Spheres”?
April 27, 2017 (000295)
A comet’s tail points in which direction?
ANSWER: Away from the Sun.
April 26, 2017 (000294)
Where in space is Cassini’s division?
ANSWER: Between two rings of Saturn.
April 25, 2017 (000293)
What is our Sun’s sunspot cycle?
ANSWER: 11 Years.
April 24, 2017 (000292)
What are the processes currently recognized as causing the Van Allen Radiation Belt?
ANSWER: It is generally understood that the inner and outer Van Allen belts result from different processes. The inner belt, consisting mainly of energetic protons, is the product of the decay of so-called “albedo” neutrons which are themselves the result of cosmic ray collisions in the upper atmosphere. The outer belt consists mainly of electrons. They are injected from the geomagnetic tail following geomagnetic storms, and are subsequently energized through wave-particle interactions.
April 23, 2017 (000291)
What is the faster spacecraft ever?
ANSWER: After a five-year jaunt through space, NASA’s robotic Juno spacecraft arrived at Jupiter on July 4, 2016, and the gas giant’s impressive gravity accelerated the probe to approximately 165,000 mph (265,000 km/h) relative to Earth. This made Juno the fastest-moving human-made object in history.
April 22, 2017 (000290)
How many people have walked on the moon?
ANSWER: In total twelve people have walked on the Moon. Besides Neil Armstrong and Buzz Aldrin – who were the first two astronauts to leave their bootprints on the Moon — there were also Pete Conrad, Alan Bean, Alan Shepard, Edgar Mitchell, David Scott, James Irwin, John Young, Charles Duke, Eugene Cernan, and Harrison Schmitt.
April 21, 2017 (000289)
What evidence supports the existence of Dark Energy?
ANSWER: The evidence for dark energy is indirect but comes from three independent sources: (1) Distance measurements and their relation to redshift, which suggest the universe has expanded more in the last half of its life.
(2) The theoretical need for a type of additional energy that is not matter or dark matter to form the observationally flat universe (absence of any detectable global curvature).
(3) It can be inferred from measures of large scale wave-patterns of mass density in the universe.
April 20, 2017 (000288)
How much does the earth weigh?
ANSWER: 5.9736 x 1024 kg or 5,973,600,000,000,000,000,000,000 kg or 5.9 sextillion tonnes
Earth’s mass constantly changes. For example, it gains an estimated 40,000 tons each year due to cosmic dust such as meteors and dust comets. It loses about 95,000 tons per year due to atmospheric escape of gasses.
April 19, 2017 (000287)
What is the largest and most massive object in the Kuiper Belt??
April 18, 2017 (000286)
What percentage of the universe is composed of visible matter?
ANSWER: Approximately 4%.
April 17, 2017 (000285)
What is the Ponzo illusion?
ANSWER: The Ponzo illusion is one possible explanation of the Moon illusion, with objects appearing “far away” (because they are “on” the horizon) appearing bigger than objects “overhead”.
April 16, 2017 (000284)
What is the speed of darkness?
April 15, 2017 (000283)
As of March 2016, what is the farthest observed galaxy?
ANSWER: Galaxy GN-z11.
April 14, 2017 (000282)
What is an Axion?
ANSWER: A hypothetical subatomic particle of low mass and energy that is postulated to exist because of certain properties of the strong force.
April 13, 2017 (000281)
What is a parsec?
ANSWER: A parsec is a unit of length used in astronomy, approximately equal to 3.261 light years.
April 12, 2017 (00027)
How does the sun burn? Is there oxygen in space? Isn’t that needed for fire?
ANSWER: The burning in a fire is a chemical reaction, requiring oxygen. If such a chemical reaction were responsible for the heat of the Sun, the Sun would have lasted for less than 100 million years. We know, however, that the Sun must be several billion years old. Therefore, a greater source of energy is required.
We now know that the Sun is powered by nuclear fusion reactions taking place at the center of the glowing ball of gas that we observe from the Earth. Unlike the Earth’s atmosphere, most of the gas in the universe is hydrogen. The Sun’s energy primarily comes from the fusion of hydrogen into helium. The glow we see from the Sun’s surface is from gas that is kept hot by heat from these fusion reactions at the Sun’s center. The temperature of the gas at the surface of the Sun is about 6000 degrees. The temperature at the center of the Sun is 16 million degrees!
So, although the Sun is very hot, there is no fire in or on the Sun in the sense of a chemical wood fire or candle flame here on Earth that requires oxygen to burn.
The amount of oxygen in space is tiny compared to the amount of hydrogen (more than 1000 hydrogen atoms for each atom of oxygen). Nevertheless, oxygen is still the third-most abundant element and was necessary for the water and, ultimately, life on Earth. The precise amount of oxygen in the Sun is currently being debated and revised, and this has important consequences for the precise modeling of the Sun’s interior.
April 11, 2017 (00026)
What is the velocity of plasma from a solar flare as it heads toward Earth?
ANSWER: An important point needs to be made before answering this question. Geomagnetic storms are observed to be primarily if not entirely associated with large ejections of mass from the Sun called coronal mass ejections. Coronal mass ejections (CMEs) were originally thought to be driven by solar flares. It is now known that many CMEs occur without any observable flare associated with them. Likewise, many flares occur for which no associated CME is observed. Therefore, phenomena associated with geomagnetic storms such as power grid failures, many satellite failures, and the aurora are most closely associated with CMEs rather than flares. On the other hand, interruptions in radio communications and expansion of the Earth’s atmosphere, resulting in increased drag on satellites in low Earth orbit, are associated with radiation from flares. The electromagnetic radiation from flares travels at the speed of light and reaches the Earth in eight minutes. CMEs, on the other hand, travel at speeds from 100 to 1000 kilometers per second and take several days to reach the Earth. The relative importance of studying CMEs versus flares for the purpose of predicting many phenomena at the Earth is presently a subject of much controversy.
April 10, 2017 (00025)
What special precautions are taken aboard the space shuttle to prevent damage to their electronic components and how are the astronauts protected?
ANSWER: The primary protection is the Shuttle orbit. The altitude of the Shuttle is typically 300-500 km (200-300 miles) above sea level. This is well within the Earth’s magnetic field (the “magnetosphere”) and below the Earth’s radiation belts (the van Allen belts). This magnetic field protects us from most of the charged particles from space, including from the Sun. Since these charged particles can travel along the Earth’s magnetic field to lower altitudes at the poles, however, the Shuttle orbit also avoids the regions around the north and south poles. (Enhanced fluxes of charged particles around the poles are responsible for the beautiful auroral displays visible at high latitudes). Manned missions to the Moon or Mars are much more dangerous, since these require leaving the protection of the Earth’s magnetic field.
Some high-energy charged particles (“cosmic rays”) do penetrate down to the Shuttle orbit and to the surface of the Earth. Collisions with the Earth’s atmosphere stops most of these particles. The flux of these particles is higher at the Shuttle, however, since its orbit is above much of the atmosphere. Therefore, the risk of damage is higher at the Shuttle orbit than at the surface of the Earth. The Shuttle shroud does provide protection, but not from the highest energy particles. The Shuttle astronauts have in fact seen flashes resulting from the interaction of high-energy protons with their eyes. Nevertheless, the increased health risk is not unacceptably high.
April 9, 2017 (00024)
What is the duration of a solar flare – minutes? hours? days?
ANSWER: The duration of a solar flare in the energetic hard x-rays is seconds to minutes (this is called the impulsive phase of the flare). The evolution of the less energetic soft x-rays from a flare is more gradual. This emission can last from minutes to hours.
April 8, 2017 (00023)
Who was the first US woman in space?
ANSWER: The first American Women in space was Sally Ride. She flew on STS-7, which launched on June 18, 1983.
April 7, 2017 (00022)
Who made the first space walk? ?
ANSWER: Ed White made the United States’ first spacewalk on 3 June 1965 during the Gemini 4 mission.
April 6, 2017 (00021)
What are constellations?
ANSWER: A constellation is formally defined as a region of the celestial sphere, with boundaries laid down by the International Astronomical Union (IAU). The constellation areas mostly had their origins in Western-traditional patterns of stars from which the constellations take their names.
April 5, 2017 (00020)
Where on Earth can you see all the stars withing a 24 hour period?
ANSWER: On the equator.
April 4, 2017 (00019)
What is zenith?
ANSWER: The point directly above you when looking up at the sky.
April 3, 2017 (00018)
What is the definition of the word astronomy?
ANSWER: Astronomy (from the Greek ἀστρονομία from ἄστρον astron, “star” and -νομία -nomia from νόμος nomos, “law” or “culture”) means “law of the stars” (or “culture of the stars” depending on the translation).
April 2, 2017 (00017)
What causes gravitational waves and when were they first discovered?
About 1.3 billion years ago (back when the first plants were showing up on Earth’s surface), two black holes collided in a titanic event. They eventually merged to become one very massive black hole with the mass of about 62 suns. It was an unimaginable event and created ripples in the fabric of space-time. They showed up as gravitational waves, first detected in 2015, by the Laser Interferometer Gravitational Wave Observatory (LIGO) observatories in Hanford, WA and Livingston, LA.
April 1, 2017 (00016)
What will Osiris-REX Discover at Asteroid Bennu?
ANSWER: The hope is that Bennu will tell us about life in both a cosmic and literal sense. An ancient and pristine object, Bennu is like a time capsule, preserving the conditions of the early Solar System when all the planets formed. The asteroid is also loaded with carbon, an essential element for life as we know it, so studying Bennu could teach us more about the origin of Earth’s flora and fauna.
March 31, 2017 (00015)
If our entire solar system could fit into a coffee cup, how big would our galaxy be (The Milky Way)?
ANSWER: The North American Continent
March 30, 2017 (00014)
The precise position of the Sun at noon each day changes over a period of a year, describing a “figure 8” in the sky. What is this called?
ANSWER: The Analemma
(Article)March 29, 2017 (00013)
How are Magnifcation and Focal Ratios determined?
March 28, 2018 (00012)
What is collimation and how is it accomplished?
March 27, 2017 (00011)
What did the Earth do in 1910 that caused unnecessary fear for many people around the world?
ANSWER: Passed through Halley’s Comet tail.
March 26, 2017 (00010)
Just after New Moon, we can faintly see the part of the Moon that is still in shadow.
What famous person is the first one known to recognize that this is from “earthshine” (sunlight reflected off the Earth, to the Moon, and back)?
ANSWER: Leonardo da Vinci
March 25, 2017 (00009)
When there are two full moons in the same calendar month the second one is called a “Blue Moon.”
How often does this event happen on average?
Answer: 2 1/2 to 3 Years
March 24, 2017 (00008)
What is the name of the most prominent crater on the Moon?
March 23, 2017 (00007)
In 1609 Galileo discovered four moons orbiting Jupiter. Three of them are named “Io”, “Ganymede” and “Callisto.”
What did he name the other one?
March 22, 2017 (00006)
What color is on the outside of the arc of a rainbow?
March 21, 2017 (00005)
If the Universe Is Expanding, Why Are the Milky Way and Andromeda Galaxies on a Collision Course?
To get to the answer, we will need to look at which forces operate on small and large astronomical scales (distances). The two fundamental forces at play in this case are gravity and dark energy. Gravity is certainly the more familiar of the two, so let’s start there…
March 20, 2017 (00004)
In 4-5 billion years the Sun is forecast to expand enough to engulf the earth. How fast is the Sun currently expanding each day?
Right now (and for the past 5 billion years or so, and for the next 4-5 billion years) the sun is pretty much in equilibrium — the tremendous pull of gravity due to its mass is balanced by the outflow of energy from nuclear fusion. It’s size changes a tiny, tiny fraction now and then, but this is an in-and-out type of motion, almost like respiration, as the two forces mentioned above fight to stay in balance.
March 19, 2017 (00003)
What is the Antikythera mechanism?
The Antikythera mechanism is an ancient analogue computer and orrery used to predict astronomical positions and eclipses for calendrical and astrological purposes, as well as the Olympiads, the cycles of the ancient Olympic Games.
March 18, 2017 (00002)
How did the Sun get its name?
The sun has had multiple names over the centuries, including the French word “soleil,” the Latin term “sol” from the ancient Romans and “helios” from the ancient Greeks. However, after Germany coined the term “sonne,” the word translated into English became “sonne” and later just “sun,” according to NASA.
March 17, 2017 (00001)
What is Planck time and how many units are in one second?
The Planck time is the length of time at which no smaller meaningful length can be validly measured due to the indeterminacy expressed in Werner Heisenberg‘s Uncertainty Principle. Theoretically, this is the shortest time measurement that is possible. Planck time is roughly 10−44 seconds. However, to date, the smallest time interval that was measured was 10−21 seconds. One Planck time is the time it would take a photon traveling at the speed of light to cross a distance equal to one Planck length.