(628)-272-0788 info@etutorworld.com

Components of the universe

Grade 8 Science Worksheets

What’s the Scale of the Universe?

Everything that exists anywhere in space and time constitutes the Universe. What’s the scale of the entire universe? Let’s start with our own star, the Sun. Our sun is 865,370 miles in diameter. In comparison, our Earth is only 7,917.5 miles in diameter. Our planet is on average 93 million miles away from our sun. We call this distance 1 Astronomical Unit (1 AU). Now that’s a long way off already. Let’s notch it up a bit…

Our sun, earth, moon, the other planets and their moons, and many more heavenly bodies like asteroids and comets – indeed, every bit of matter that goes around our sun – together constitutes our Solar System. The solar system is estimated to be about 178.62 billion miles, or 1921.56 AU, in diameter. Let’s notch it up a bit more…

Schedule a Free session to clear worksheet doubts

No credit card required, no obligation to purchase.
Just schedule a FREE Sessions to meet a tutor and get help on any topic you want!

Hundreds of billions of such Stars including our own sun are grouped together to form one Galaxy, which we call the Milky Way Galaxy. Our sun is an inconspicuous speck in this vast galaxy. The Milky Way galaxy is shaped like a spiral that is 100,000 – 150,000 light-years across. (One light-year is the distance traveled by light in one year, which is about 6 trillion miles. Do the math). Let’s notch is up one more time …

There are estimated to be 100 billion such galaxies, could even be twice as many or more, in the entire universe. The observable universe – those parts of the universe that we have been able to see with our most sophisticated telescopes – is estimated to be 93 billion light-years in diameter. That’s the scale of the universe we know!

Galaxies

A galaxy consists of stars, dust, gas and other matter held together by the forces of gravity. Galaxies have a diameter anywhere from a few thousand to several hundred thousand light-years. Galaxies are flung far apart from one another, often measured in Parsecs and Megaparsecs, where one parsec is 3.26 light-years and a megaparsec is a million times that!

On a dark night in the northern hemisphere you might be able to discern the shape of our own galaxy, the Milky Way, in the form of a spiral. You may also spot the galaxy nearest to us, the Andromeda Galaxy, which is 2.5 million light-years away. But the billions of other galaxies are too far away to spot without powerful telescopes.

The Hubble telescope focused on a small patch of ‘empty sky’(marked as XDF – see picture on left) for about 100 hours and collected light emitted by thousands of undiscovered galaxies (See picture on right).

eTutorWorld Understands Math Tutoring | Online Math Worksheets are Important Tools

Understanding graphs, charts, and opinion polls in a newspaper, for calculating house and car payments, and for choosing a long-distance telephone service are impossible without strong math skills …and the only way to develop strong math skills is by constant practice.

‘Practice makes a man perfect’ holds true for no other field better than for math. A middle or high school student must set aside a minimum of an hour for math every day. Other than textbooks, worksheets help you revise and understand concepts better.

Our expert tutors prepare online maths worksheets that are age and grade-appropriate. Grade-wise math worksheets for Elementary Math, Arithmetic, Pre-Algebra, Algebra, Geometry, Trigonometry, Statistics, Pre-Calculus and Calculus can be solved to improve math skills, to get ahead or to even catch up.

You may download these FREE online math worksheets in the PDF format, and then print and email us their solutions for a free evaluation and analysis by eTutorworld’smath expert tutors.

You may solve these worksheets by yourself or with your peers while studying together.

The Answer Key at the end of each worksheet allows for a self-evaluation.

Personalized Online Tutoring

eTutorWorld offers affordable one-on-one live tutoring over the web for Grades K-12, Test Prep help for Standardized tests like SCAT, CogAT, MAP, SSAT, SAT, ACT, ISEE and AP. You may schedule online tutoring lessons at your personal scheduled times, all with a Money-Back Guarantee. The first one-on-one online tutoring lesson is always FREE, no purchase obligation, no credit card required.

For answers/solutions to any question or to learn concepts, take a FREE CLASS.

No credit card required, no obligation to purchase.
Just book a free class to meet a tutor and get help on any topic you want!

Galaxies are classified by their appearance and shape. The most common shapes are Spiral, Elliptical and Irregular. Others can be sausage-shaped or flattened balls, or like rugby balls.

Our Milky Way galaxy and the nearby Andromeda galaxy are spiral. The Small and Large Magellanic Cloud are examples of irregular galaxies. Most other galaxies simply have alphanumeric names, as seen in the pictures below

Check Point

  1. One Astronomical Unit (AU) is –
    1. Roughly 93 million miles
    2. The average distance between the sun and earth
    3. A unit of distance in space
    4. All of the above
  2. The shape of the Milky Way Galaxy is –
    1. Irregular
    2. Spiral
    3. Elliptical
  3. Distances between galaxies can be measured in –
    1. Parsecs
    2. Megaparsecs
    3. Light-years
    4. All of the above
  4. The Milky Way galaxy is about –
    1. 100,000 to 150,000 light-years across
    2. 93 million miles across
    3. 93 billion light-years across
    4. 93 million light-years across
  5. The galaxy nearest to our galaxy is –
    1. Milky Way
    2. Messier
    3. Andromeda
    4. NGC 3923

Answer Key

  1. d) All of the above
  2. b) Spiral
  3. d) All of the above
  4. a) 100,000 to 150,000 light-years across
  5. c) Andromeda

Learn more about Tools Measurement and SI Units and other important topics with 8th Grade Science Tutoring at eTutorWorld. Our expert science tutors break down the topics through interactive one-to-one sessions. We also offer the advantage of customized lesson plans, flexible schedules and convenience of learning from home.

Schedule a Free session to clear worksheet doubts

No credit card required, no obligation to purchase.
Just schedule a FREE Sessions to meet a tutor and get help on any topic you want!

Pricing for Online Tutoring

Tutoring Package Validity Grade (1-12), College
5 sessions 1 Month $139
1 session 1 Month $28
10 sessions 3 months $269
15 sessions 3 months $399
20 sessions 4 months $499
50 sessions 6 months $1189
100 sessions 12 months $2249

Images Credit:

https://upload.wikimedia.org/wikipedia/commons/9/9b/XDF-scale.jpg

https://upload.wikimedia.org/wikipedia/commons/2/22/Hubble_Extreme_Deep_Field_%28full_resolution%29.png

https://www.bibliotecapleyades.net/imagenes_universo/cosmos132_01.jpg

https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/M101_hires_STScI-PRC2006-10a.jpg/428px-M101_hires_STScI-PRC2006-10a.jpg