You go outside, look up, and see a bright star glowing in the western sky. What's that, you wonder? You pull out your cell phone, key in your ZIP code, and voilà, you have the answer: it's not a star at all — it's the planet Venus!

With Sky & Telescope's Mobile Sky Chart, you get a simulated naked-eye view of the heavens from any location in the United States, on any date, at any time of night.

There are two ways to display the sky on S&T's Mobile Sky Chart: the Horizon View provides a panoramic naked-eye scene from the horizon two-thirds of the way up toward overhead, and the All-Sky Chart represents the entire sky currently visible. Both displays are labeled with compass points so you can match the chart to the direction you're facing. Moving around the sky on either chart is as simple as pushing the phone's arrow buttons.

S&T's Mobile Sky Chart includes the following features:

• Display of some 900 stars; about half of these are above the horizon at any time

• Display of star names of the 26 brightest stars

• Display of the Moon and five naked-eye planets (Mercury, Venus, Mars, Jupiter, and Saturn)

• Display of 86 constellations with stick-figure lines and labels

• Viewing location determined from ZIP code

• Navigation (panning and zooming) of the sky-chart display via the left/right/up/down and number keys

Access Sky & Telescope's Mobile Sky Chart via this service:

• Verizon's Get It Now^SM

Available on the these handsets:

• Audiovox CDM 8900, CDM 8910
• LG 4600, 6000, 7000
• LG VX4400, VX4400B, VX4500, VX6000
• Motorola T720
• Samsung SCH-a610, SCH-a650, SCH-a670

Generally, you acquire the application by using your wireless phone to connect to your service provider. For example, from the Verizon main menu, choose Get It Now, then Get Apps. Then, after the OK screen, click on the shopping-cart icon. Next press Start, then Get Going, then Education. Finally, choose the Mobile Sky Chart. It may sound complicated, but it's not.

For more information:

• User Guide
• Our technology partners: Nuvo Studios and M7 Networks
• Press release about S&T's Mobile Sky Chart

The images and graphics shown in this article and related articles are for display purposes only. The color, resolution, and clarity of the images and graphics in Sky & Telescope's Mobile Sky Chart may vary depending on a number of factors including, but not limited to, the make and model of the wireless device.