Download This Sample
This sample is exclusively for KidsKonnect members!
To download this worksheet, click the button below to signup for free (it only takes a minute) and you'll be brought right back to this page to start the download!
Sign Me Up
Table of Contents
The Milky Way is a barred spiral galaxy that contains our Solar System. It is vast, spanning approximately 100,000 light-years in diameter, and it is home to hundreds of billions of stars, as well as planets, asteroids, and other celestial objects. Our galaxy is situated on the outskirts of the larger Virgo Supercluster and is just one of billions of galaxies in the observable universe.
See the fact file below for more information about the Milky Way, or you can download our 30-page Milky Way worksheet pack to utilize within the classroom or home environment.
Key Facts & Information
HISTORY OF THE MILKY WAY
- The Milky Way is an ancient barred spiral galaxy, estimated to be approximately 13.6 billion years old, featuring expansive rotating arms extending across the vast expanse of the universe.
- According to Las Cumbres Observatory, our home galaxy’s disk is around 100,000 light-years in diameter and just 1,000 light-years thick.
- The Solar System orbits the center of the Milky Way in the same way as Earth orbits the Sun.
- According to Interesting Engineering, our Solar System takes around 250 million years to complete a single revolution while traveling through space at speeds of over 515,000 mph (828,000 kmph).
- When our planet was in this position the last time, dinosaurs were only emerging, and mammals had yet to form.
- If the Milky Way were a metropolis, we’d be around 25,000 to 30,000 light-years away in suburbia.
- Living in the outer regions is terrific; we reside within a smaller district, the Orion-Cygnus Arm, between the more expansive Perseus and Carina-Sagittarius arms.
- The Scutum-Centaurus and Norma arms can be found by traveling toward the city center.
- We can see the galactic city’s brilliant lights racing through the night sky on a clear night without light pollution.
- Our galaxy derives its name from this milky white ring of stars, dust, and gas that serves as our window into the cosmos.
- Sagittarius A* is a supermassive black hole at the center of the Milky Way. This beast, about 4 million times the Sun’s mass, eats anything that comes too close, feeding on an abundant supply of star material that allows it to develop into a behemoth.
- In 2022, we made our first-ever observation of the voracious entity at the center of our galaxy using an innovative method that enabled us to capture the silhouette of the black hole.
- The name “Milky Way” originates from its appearance as a milky-white band stretching across the night sky, as described by the American Museum of Natural History (AMNH). This milky band arose in Greek mythology after the goddess Hera splashed milk over the sky.
- The Milky Way has several names across the world. It is known as the “Silver River” in China and the “Backbone of Night” in South Africa’s Kalahari Desert.
SIZE, STRUCTURE, AND MASS
- It used to be infamously difficult to study the Milky Way. Astronomers have compared the task to attempting to explain the size and structure of a forest while lost in it.
- We lack perspective from our vantage point on Earth. However, two groundbreaking space telescopes launched during the 1990s helped usher in a golden age of Milky Way study.
- Substantial advancements have been made, notably with the initiation of the European Space Agency’s (ESA) Gaia mission in 2013.
- Astronomers used telescopes to determine the basic shape and structure of some of the nearest galaxies before they realized they were looking at galaxies.
- However, rebuilding the shape and structure of our own galactic home proved time-consuming and painstaking.
- The procedure entailed creating star catalogs, tracking their locations in the sky, and calculating their distance from Earth.
- The guru of the galactic system, Dutch astronomer Jan Oort, was the first to determine that the Milky Way isn’t stationary but rotates, and he computed the speeds at which stars at various distances circle the galactic center.
- Oort also determined our sun’s location in the massive cosmos. (The Oort Cloud, a vast collection of billions of comets, was named after him.)
- Gradually, a complicated image of a seemingly ordinary spiral galaxy formed.
- Sagittarius A* is a supermassive black hole in the heart of the Milky Way. The black hole, found in 1974, has a mass equal to four million suns and may be seen in the sky using radio telescopes near the constellation Sagittarius.
- Everything else in the universe revolves around this potent portal to oblivion. The galactic bulge is a densely packed area of dust, gas, and stars in its immediate environs.
- According to ESA, the Milky Way’s bulge is peanut-shaped and is 10,000 light-years wide. It is home to 10 billion stars (out of the Milky Way’s total of roughly 200 billion), the majority of which are ancient red giants that originated during the early stages of the galaxy’s growth.
- The galactic disk extends beyond the bulge. This structure, which is 100,000 light-years broad and 1,000 light-years thick, is home to most of the galaxy’s stars, including our sun.
- Clouds of stellar dust and gas spread the stars in the disk. The edge-on image of this disk expanding toward the galactic core takes our breath away when we look up at night.
- Stars in the disk circle the galactic center, generating whirling streams that appear to emerge from the galactic bulge-like arms.
- The formation of spiral arms in galaxies remains a subject of ongoing research. However, recent discoveries suggest that these arms emerge and dissipate within relatively short timeframes, typically spanning up to 100 million years, a relatively brief duration considering the galaxy’s overall evolutionary timeline of 13 billion years.
- Stars, dust, and gas are more densely packed inside those arms than in the more sparsely filled portions of the galactic disk, and this higher density causes more intense star formation.
- Consequently, stars within the galactic disk exhibit notably younger ages compared to stars found in the bulge.
- “Spiral arms can be likened to traffic jams, where gas and stars congregate and experience reduced speed within these regions. As material passes through these densely populated spiral arms, it undergoes compression, subsequently promoting greater star formation,” explained Denilso Camargo, a researcher from Brazil’s Federal University of Rio Grande do Sul.
- As per information from the National Science Foundation (NSF), the Milky Way exhibits four spiral arms. Among these, the prominent arms are Perseus and Scutum-Centaurus, while the Sagittarius and Local Arms are comparatively less pronounced.
- Using Gaia data, scientists debate these arms’ precise position and structure.
- According to ESA, the Milky Way disk is twisted rather than flat. It precesses like a wobbly spinning top as it revolves. This big ripple wobble circles the galactic center far slower than the stars in the disk, completing a full rotation in 600 to 700 million years.
- Astronomers believe this ripple results from a previous collision with another galaxy.
- According to an ESA statement, globular clusters, groupings of old stars, and roughly 40 dwarf galaxies orbit or collide with the larger Milky Way scattered across the disk and bulge.
- All of this is encircled by a spherical halo of dust and gas twice the diameter of the disk.
- Astronomers think that a halo of invisible dark matter surrounds the entire galaxy. Because dark matter does not radiate light, its presence may only be determined indirectly by the gravitational forces of stars in the galaxy.
- According to calculations, this perplexing matter accounts for up to 90% of the galaxy’s mass.
- According to the latest NASA estimations, the Milky Way’s mass, including dark matter, is 1.5 trillion solar masses. The observable matter within the galaxy is distributed among approximately 200 billion stars, their accompanying planets, and the extensive expanses of dust and gas that occupy the regions of interstellar space.
- Astronomers are still determining how many planets there are in the Milky Way, considering we’ve only discovered a few thousand. Still, one NASA estimate says there are more than 100 billion.
- The number of solar systems in the Milky Way is still being determined as scientists are still seeking planets.
THE SUN IN THE MILKY WAY
- The Sun is around 26,000 light-years away from the black hole Sagittarius A*, located roughly in the center of the galactic disk.
- The Sun takes 230 million years to complete a full circle around the galactic center, traveling at 515,000 mph (828,000 kph).
- The Sun is on the border of the Milky Way’s Local Arm, one of the galaxy’s two smaller spiral arms.
- According to ESA, researchers discovered in 2019 that the Sun is effectively surfing a wave of interstellar gas that is 9,000 light-years long, 400 light-years broad, and undulates 500 light-years above and below the galactic disk using data from the Gaia spacecraft.
- The Solar System’s planets do not revolve on the plane of the galaxy but tilt by around 63 degrees.
- “It’s akin to navigating through the cosmos at an angle,” shared Merav Opher, an astronomer from George Mason University in Virginia, during a conversation with Space.com.
THE BLACK HOLE IN THE MILKY WAY
- Sagittarius A* is the name of the Milky Way’s black hole.
- The black hole is essentially inert, making observation difficult. Sagittarius A*, discovered in 2008 by astronomers Reinhard Genzel and Andrea Ghez, has a mass 4.3 million times that of the Sun.
- The diameter is approximately 14.6 million miles (23.5 million kilometers). The Milky Way is around 100,000 light-years across and 1,000 light-years thick.
- Around Sagittarius A*, a gigantic disk of gas billows as far as 5 to 30 light-years from the supermassive black hole.
- This vast yet tenuous region of gas provides some material for Sagittarius A* activity.
- The area is known to release X-rays due to gas feeding or friction within the disk as temperatures reach 18 million °F (10 million C°).
- Scientists would like to learn more about this supermassive black hole to understand how it developed and the conditions that allowed it to expand.
- Smaller black holes may grow fairly huge as they consume dust and gas in the surrounding environment, or smaller black holes may merge to form something more monstrous.
- Scientists are generally developing better models for stellar-mass and intermediate-mass black holes. These things originate when massive stars, often the mass of our sun, collapse after nuclear fusion stops.
- They shrink to a gravitationally strong entity that can twist time and space around it so much that light can no longer escape because they can no longer halt the gravitational collapse.
- We’re always learning more about Sagittarius A*, thanks to efforts like the first-ever photograph of the black hole, captured on May 12, 2022.
- The photograph recorded faint quantities of light created by heated matter rushing at breakneck speed into the black hole’s center; the image is a high-definition shadow.
- This imaging requires an extensive network of observatories spread across the globe, about the size of the Earth, which was made possible by the Event Horizon Telescope (EHT).
THE SOLAR SYSTEM
- The Solar System is located within the Milky Way galaxy, a barred spiral galaxy comprising billions of stars.
- The Solar System is positioned relatively close to the center of the Milky Way galaxy.
- The Solar System orbits the galactic center at a distance of approximately 25,000 to 28,000 light-years.
- It takes the Solar System around 225-250 million years to complete one full orbit around the galactic center.
- The Sun and its planets are situated within the Orion Arm (also called the Local Arm) of the Milky Way.
- The Orion Arm is a minor spiral arm extending outward from the galactic center.
- The Solar System is about two-thirds of the way from the galactic center to the outer edge of the Orion Arm.
- While the Solar System is relatively close to the galactic center, it’s not at the exact center of the Milky Way.
- The region of the Milky Way where the Solar System is located contains a significant number of stars, contributing to the galaxy’s luminosity.
- The Solar System’s location within the galaxy exposes it to the interstellar medium, including gas, dust, and cosmic rays.
- The Solar System’s position within the Orion Arm grants it a view of nearby stars and the Milky Way’s spiral structure.
- The Solar System’s location in the Milky Way influences the visible stars and constellations from Earth’s vantage point.
- The Solar System lies near the plane of the Milky Way, where most of the galaxy’s stars and dust are concentrated.
- From within the galaxy, the Milky Way appears as a band of light and dark patches stretching across the night sky.
- While not positioned at the very center of the Milky Way, the Solar System enjoys a view of the galactic core.
- The Solar System’s position gives astronomers insights into the galactic bulge, bar, and spiral arms.
- The Solar System’s orbit contributes to the overall rotation of the Milky Way galaxy.
- The Solar System’s location within the Milky Way’s environment likely shaped its formation and composition.
- The Solar System is in constant motion within the Milky Way, orbiting the galactic center while the galaxy moves through space.
GALACTIC EVOLUTION AND COSMIC ROLE
Galactic Evolution:
- The Milky Way formed from gas and dust in the early universe around 13.6 billion years ago.
- It developed its spiral structure over billions of years, composed of a central bulge, a disk, and spiral arms.
- The Milky Way’s stars divide into distinct populations, including the older Population II stars and younger Population I stars.
- The Milky Way continuously forms new stars in regions like molecular clouds while older stars exhaust their fuel and evolve.
- The Milky Way has undergone interactions with other galaxies, including the merging of smaller galaxies, influencing its structure.
- Observations suggest a supermassive black hole, Sagittarius A*, at the galactic center, influencing the galaxy’s dynamics.
- The Milky Way hosts various star clusters, including open and globular clusters and nebulae like H II regions.
Cosmic Role:
- The Milky Way is home to our Solar System, Earth, and countless other celestial bodies.
Milky Way Worksheets
This fantastic bundle includes everything you need to know about the Milky Way across 30 in-depth pages. These ready-to-use worksheets are perfect for teaching kids about the Milky Way. Our galaxy is situated on the outskirts of the larger Virgo Supercluster and is just one of billions of galaxies in the observable universe.
Complete List of Included Worksheets
Below is a list of all the worksheets included in this document.
- Milky Way Facts
- Milky Mysteries
- The Vast Universe
- Arms of the Milky Way
- Exploring the Milky Way
- The Big Bang Theory
- Galactic Grid
- Cosmic Pairs
- Stellar Sonnet
- The Milky Way
- The Silver River Model
Frequently Asked Questions
What is the Milky Way?
The Milky Way is a barred spiral galaxy that contains our solar system. It is a vast collection of stars, planets, gas, dust, and dark matter, and it is one of billions of galaxies in the universe.
How did the Milky Way get its name?
The name “Milky Way” comes from its appearance as a faint, milky band of light across the night sky. This band is composed of countless stars and is more visible in areas with low light pollution.
How big is the Milky Way?
The Milky Way is estimated to be about 100,000 to 120,000 light-years in diameter. It contains hundreds of billions of stars, along with various celestial objects like nebulae, star clusters, and supermassive black holes at its center.
What is the center of the Milky Way like?
The center of the Milky Way is home to a supermassive black hole called Sagittarius A* (pronounced “Sagittarius A-star”). This black hole has a mass of around 4 million times that of the Sun and is surrounded by a dense region of stars and gas.
How old is the Milky Way?
The Milky Way is estimated to be around 13.6 billion years old, nearly as old as the universe itself. It formed from the gravitational collapse of a region within the early universe, and its age is determined by the age of its oldest stars.
Link/cite this page
If you reference any of the content on this page on your own website, please use the code below to cite this page as the original source.
Link will appear as Milky Way Facts & Worksheets: https://kidskonnect.com - KidsKonnect, October 19, 2023
Use With Any Curriculum
These worksheets have been specifically designed for use with any international curriculum. You can use these worksheets as-is, or edit them using Google Slides to make them more specific to your own student ability levels and curriculum standards.