As you read the rest of Jessica Williams's blog post, identify her main ideas and note the details she provides to support and explain those ideas. Then answer the questions beside the blog entry, which will help you summarize the article.
According to this blog post, what is solar conjunction, and why is it a problem?
The second paragraph describes the movement of Earth and Mars. Why did the author include this detail? What main idea does it support?
What are "noisy measurements"? What do they have to do with the main idea of this post?
How does Jessica Williams's team at NASA deal with solar conjunction? What do they do when it happens?
Summarize the information provided in this blog post. Remember that a summary includes only the main ideas--not small details.
| Your Responses | Sample Answers |
|---|---|
| A solar conjunction occurs when the Earth and another plant are on opposite sides of the solar system from one another. It is a problem because it causes radio signals to cut out, or become very noisy. The interference prevents NASA scientist from learning anything about the plant while the solar conjunction is occurring. | |
| It describes the two planets' distinct difference in distance from the sun, and their tendency to end up on opposite sides of the solar system (a solar conjunction) because of the time differences between them. | |
| Noisy measurements prevent a navigation team from figuring out exactly where a spaceship is. The phrase describes one of the effects of solar conjunction. | |
| They just wait for Mars to come out from behind the sun. (They do a "wait out" untill the solar conjunction is over.) | |
| Sometimes when scientist are using spaceships to study other planets, solar conjunctions will occur and "shut down" research until the event passes.. A solar conjunction occurs when the Earth and another plant are on the opposite sides of the solar system. When a solar conjunction occurs, the Navigation team can't locate exactly where the spacecraft is. The scientists must wait until the solar conjunction ends before continuing their research with that spaceship because the energy of the sun between them and the planet is too hot to allow them connect with the instruments on board the spaceship. | |
Solar Conjunction: When The Sun Gets In The Way
I am a Navigation Engineer in the Mission Design and Navigation section at the Jet Propulsion Laboratory in Pasadena, California. As a Mars Reconnaissance Orbiter Navigator, my job is to determine where the spacecraft is (orbit determination) and where it is going (orbit prediction). I also keep the spacecraft on course by performing propulsive burns using the spacecraft engines.
The Earth and Mars both orbit the sun. Because Mars is farther away from the sun than is the Earth, the length of a Mars year is longer than the length of an Earth year (1 Mars year is about 1.9 Earth years). These different orbit periods cause the Earth and Mars to sometimes be on opposite sides of the solar system from one another. This event is called Solar Conjunction.
During Solar Conjunction, radio signals transmitted by the Deep Space Network to the Mars Reconnaissance spacecraft (and vice versa) must pass through the solar corona. Due to signal interference, the measurements that the Navigation team use for orbit determination become very noisy. Noisy measurements mean that the Navigation team can't figure out exactly where the spacecraft is and where it is going. Without accurate measurements (and an accurate orbit determination solution), the Mars Reconnaissance spacecraft cannot perform precise targeted science observations. The best thing for the team to do is to "wait out" Solar Conjunction until the signal noise levels go back to normal levels (when Mars re-emerges from behind the sun). For Mars Reconnaissance Orbiter, this Solar Conjunction period starts around April 4, 2013, and lasts until May 1, 2013. During this time, science observations are suspended and we won't be receiving any new images.
But not to worry! We should be back to our normal routine in May, so stay tuned!
