Study Guide for Unit 7

Jenn says there are thousands, maybe even millions of galaxies in the universe. What is her error?

• There are only a few hundred galaxies in the universe.
• The universe contains exactly one million galaxies.
• There are over two trillion galaxies in the universe.
• There are billions of galaxies in the universe.

Why do we have no satellites or probes that have reached distant stars? What technology do we use to study distant stars and galaxies?

• We have sophisticated satellites equipped with advanced technology capable of traveling vast distances across space to reach distant stars, allowing us to explore and study the farthest reaches of our universe.

• Due to vast distances and propulsion limits, we study them with telescopes and observational tech

• We study distant stars using unmanned satellites and space telescopes due to vast distances and current propulsion limits.

• Probes have reached the nearest star system, a monumental achievement in space exploration.

Remember a Light Year is a measure of distance using how FAR light travels in one year. With that in mind, how long does it take light from a star to reach Earth if research shows that the star is 6 ly away from earth?

• 1 year
• 6 years
• 12 years
• 3 years

Do we study space, other planets, stars and galaxies, by direct observation or remote observation? Why?

• We study them through remote observation because they are far away.

• We study them using only telescopes on Earth because they are close.

• We study them only through direct observation because they are nearby.

• We study them by sending humans to other planets because it is easy to do.

Many years ago, our solar system was said to have 9 planets compared to the 8 we now call our solar system. In 2006 the planet Pluto was demoted to 'dwarf planet' because science discovered its orbit wasn't clear of other bodies. What quality of scientific knowledge does this demonstrate?

• Scientific knowledge is self-correcting.
• Scientific knowledge is based on opinion.
• Scientific knowledge is always correct.
• Scientific knowledge is static (stays the same).

The sun and the moon look to be the same size, but we know that the radius of the sun is 696,000 kilometers while the moon has a mean radius of only 1,737.5 kilometers. Why do they appear to be the same size?

• It's due to the relative distances and sizes of the sun and moon.

• The sun and moon are the same size because they are both spherical.
• The moon reflects sunlight, making it seem larger than it is.
• The sun appears smaller due to atmospheric distortion.

Why would we use a model to study the following concepts: solar system, rock cycle, plate tectonics, and atomic theory?

• Models simplify complex concepts for easier understanding and study.

• Models are used to predict future events without any data.
• Models are only useful for physical objects and not abstract concepts.
• Models are created to replace the need for real-world experiments.