Orbits and How They Work

Warm-Up Questions CPS Questions (1-2) Chapter 10, Lesson 1

Chapter Overview Orbits and How They Work Maneuvering and Traveling in Space Chapter 10, Lesson 1

Lesson Overview How orbits work The different types of orbits used for different purposes Chapter 10, Lesson 1

(Note to teacher: Use “Pick a Student” button in CPS) Quick Write Can science fiction contribute to scientific progress? What other science-fiction writers can you think of who foresaw important scientific discoveries and inventions? (Note to teacher: Use “Pick a Student” button in CPS) Chapter 10, Lesson 1

How Orbits Work Momentum and Gravitational Force A satellite launched into space would keep going An orbit is the momentum of the object in a straight line and gravity pulling the object back A satellite is always falling into the planet – because it’s moving “sideways” fast enough, it never hits the planet Chapter 10, Lesson 1

Escape Velocity Because a body’s size and mass determine its gravitational pull, escape velocity differs Location and direction of launch also important Launching from near the equator helps propel rockets into space Chapter 10, Lesson 1 Courtesy of NASA

Orbital Velocity Orbital velocity – the speed an object must maintain to stay in orbit The closer an object is to Earth, the faster it needs to travel to remain in orbit The higher a spacecraft climbs from Earth, the slower it can travel and still resist gravity Chapter 10, Lesson 1 Courtesy of NOAA

How Height, Eccentricity, and Inclination Affect an Orbit Height determines the speed required for a satellite to remain in orbit A low-eccentricity object is one flying in a more- round, less-oval path Inclination – the angle an orbit takes as it circles the Earth Chapter 10, Lesson 1 Courtesy of NASA

Different Types of Orbits Used for Different Purposes Geosynchronous Earth orbit - an orbit around a planet or moon that places the satellite in the same place in the sky over a particular point on the surface each day An object in geosynchronous orbit orbits at a speed equal to the Earth’s rotation Geosynchronous orbit is over Earth’s equator and is called a geostationary orbit Chapter 10, Lesson 1

Geostationary Operational Environmental Satellites (GOES) Fly very high above the Earth in the equatorial plane Watch for atmospheric triggers of severe weather Provide scientists with consistent, long-term observations Chapter 10, Lesson 1 Courtesy of NOAA

Polar-Orbiting Operational Environmental Satellites (POES) Fly lower and closer to the Earth Sun-synchronous orbits – orbit coordinated with Earth’s rotation so that the satellite always crosses the equator at the same local time on Earth Provides information for long-range weather and climate forecasts Chapter 10, Lesson 1 Courtesy of Earth Observatory/NASA

Low-Earth Orbit (LEO) Low-Earth orbit – an orbit up to about 1,240 miles above the Earth High-Earth orbit – an orbit at an altitude of about 22,300 miles Medium-Earth orbit – one with an altitude of about 12,400 miles Chapter 10, Lesson 1

Learning Check CPS Questions (3-4) Chapter 10, Lesson 1

Activity 1: Orbits Scramble Unscramble the words on the worksheet and write them in the blanks. Then write the definitions in the spaces provided. Refer to pages 416-424 in the textbook. Chapter 10, Lesson 1

Activity 2: Orbit Distances Create a model on paper of the different orbits above Earth. Chapter 10, Lesson 1

Activity 3: GOES v. POES Debate Prepare to defend either the Geostationary Operational Environmental Satellites (GOES) or the Polar-Orbiting Environmental Satellites (POES) with your team in a lively debate. Chapter 10, Lesson 1

Technology Enrichment: Teaching With Podcasts Review several podcasts from the NASA website. Take note of how the narrator presents his or her information and data. Each group will work together to create a podcast script for a podcast on one of the  assigned topics. Be prepared to showcase your script for the other groups in class! Chapter 10, Lesson 1

Review An orbit is the constant struggle between the momentum of an object to stay in a straight line and gravity pulling the orbiting object back toward the body it circles Scientists not only consider speed and gravity when planning launches, they also must choose from many types of orbits Chapter 10, Lesson 1

Review, cont. The closer an object is to Earth, the faster it needs to travel to remain in orbit Height determines the speed required for a satellite to remain in orbit The kind of orbit a satellite uses depends on the mission Chapter 10, Lesson 1

Review Questions CPS Questions (5-6) Chapter 10, Lesson 1

Summary How orbits work The different types of orbits used for different purposes Chapter 10, Lesson 1

Next… Done – Orbits and How They Work Next – Maneuvering and Traveling in Space Chapter 10, Lesson 1 Courtesy of Earth Observatory/NASA