News, Science

Two Earth-Sized Planets Discovered

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Kepler space telescope; image: NASA
Kepler space telescope; image: NASA

Two planets have been discovered, about 1,000 light years away from Earth.

Both of the planets are about the size of Earth. Kepler-20e is slightly smaller, and Kepler-20f is slightly larger than Earth.

The surface of the planets are too hot for water to exist on them; it would not be possible for life to exist on them either. They are hot because they orbit close to a star very much like our sun.

Kepler-20e has a termperature of about 760 degrees Celcius. (In contrast, Earth’s average surface temperature is 14 degrees Celsius.)

The planets were discovered during a mission by NASA using the Kepler space telescope. They have been combing the skies searching for planets since about 2009; the mission will last about 3.5 years. One of the most important goals of the mission was to find Earth-sized planets. These two are the first ones they have found.

The planets are part of a five-planet solar system.

The discovery demonstrates for the first time that Earth-sized planets exist around other stars, said a spokesperson for the mission. (They are known as “extrasolar” planets.)

The scientists used an interesting method of discovering the planets. They monitor a section of the sky with the Kepler telescope and watch the brightness of about 145,000 stars. When the brightness of a star changes, it may indicate the presence of a planet passing by it. When it happens a few times, they become more certain it is caused by a planet.

CURRICULUM CONNECTIONS
By Kathleen Tilly

Writing/Discussion Prompt
Why do you think NASA is spending so much time and money to find undiscovered planets?  How could this new information be useful and/or important to NASA researchers and to average people?

Reading Prompt:
One strategy that can be used to comprehend a text is visualization.  Visualization is when we create pictures in our minds to go with the information that we are reading.
Read this article carefully and visualize the information in the text. What pictures do you imagine? Do these images help you to understand the text?  If so, how? If not, why?

Primary
Identify a variety of reading comprehension strategies and use them appropriately before, during, and after reading to understand texts (OME, Reading: 1.3).

Junior
Identify a variety of reading comprehension strategies and use them appropriately before, during, and after reading to understand texts (OME, Reading: 1.3).

Intermediate
Identify a variety of reading comprehension strategies and use them appropriately before, during, and after reading to understand increasingly complex texts (OME, Reading: 1.3).

Grammar Feature: Semi-colon
A semi-colon (;) is used in the following sentence: “The surface of the planets are too hot for water to exist on them; it would not be possible for life to exist on them either.”  Why do you think a semi-colon is used instead of a period?  Does the use of a semi-colon change how you decode and understand this sentence?