### Earth-like Planet Found Outside Our Solar System

Astronomers believe they have found an earth-like planet located outside our solar system in the Libra constellation. The BBC reports that the planet is `20.5 light years` from Earth, while the International Herald Tribune reported that it was `about 20 light years` away.

The earth-like planet is officially known as Gliese 581c. Scientists estimate temperatures on the planet's surface range from `0°C` to `40°C`.

`20 light years` approximates `1.17569996 x 10^14 miles`; `20.5 light years` approximates `1.20509246 x 10^14 miles`.

##### Exercises
1. `20.5 light years` is `___________ miles` more than `20 light years`.

2. Temperatures on 581c range from a low of `_______°F` to a high of `______°F`.

3. The AP issued a report saying the earth-like planet in "galactic terms is relatively nearby at ```120 trillion miles``` away." No or Yes: `120 trillion` equals `12,000 billion`.

4. 581c has a diameter about `1 1/2 times` that of planet Earth. The diameter of Earth approximates `12,756.3 km`. The diameter of 581c approximates `________________ miles`. [1 kilometer = 0.621371192 mi]

Creator: Gerald D. Thurman [gthurman@gmail.com]
Created: 25 April 2007