The Cosmic Watch, a newly updated app, allows users to view Earth from space. In the app, you can see everything from surrounding interstellar dust and gas to constellations.

A virtual planetarium could be a great tool for watching the longest total lunar eclipse of this century.

Tonight (July 27), Mars reaches opposition, meaning the Red Planet will roughly align with Earth and the sun. Additionally, the longest lunar eclipse of the 21st century occurs today. And, in just a few days, Mars will reach its closest approach to Earth since 2003. The Red Planet will also be especially bright in the night sky. All in all, the next few days will be chock-full of astronomical events and sights.

Whether you're watching these events outside or online, the Cosmic Watch, a newly updated app, can help you to track and follow what's happening in the sky. The Cosmic Watch is a simulation app that shows Earth and the sky in real time. Like a virtual planetarium, the app gives you the perspective of an astronaut viewing our planet from space. It features stunning, cosmic visuals; a calendar; an equatorial clock face and more. You can even choose to see things like interstellar gas and dust, and surrounding constellations and stars.

The Cosmic Watch alerts users of astronomical events like eclipses. This would make it a great companion for those looking to observe the lunar eclipse tonight (July 27). (Image credit: The Cosmic Watch)

Additionally, if you're looking to explore a bit more of the solar system, check out the app's new "Solar System View," which lets you shift your perspective out to the cosmos. With this feature, you can switch between a heliocentric view, where the sun is in the center, and a geocentric view, where Earth is in the center.

You can use the app as just a regular clock, but the Cosmic Watch can also notify you of upcoming astronomical events, like lunar and solar eclipses, so it could be a helpful companion for those looking to watch the events of the next few days. The app also has a "Sky View" feature that allows you to look at the stars, constellations and planets in real time when you point your device at the sky. This doesn't mean you can watch the eclipse through your phone, but it could help you to figure out what's surrounding these events in the sky.

Email Chelsea Gohd at cgohd@space.com or follow her @chelsea_gohd. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.