NASA Making Voyager Spacecraft Announcement Today: Watch It Live
An artist's illustration of NASA's Voyager 1 spacecraft, the farthest human-built object from Earth, which launched in 1977 and is headed for interstellar space.
Credit: NASA

Editor's Note: The news is out, NASA's Voyager 1 spacecraft has left the solar system and has entered interstellar space. It's Official! Voyager 1 Spacecraft Has Left Solar System

More Voyager News: 

NASA says it will hold a press conference today (Sept. 12) to discuss an apparently new development with the agency's two far-flung Voyager spacecraft at the edge of the solar system, and you can watch the announcement live online.

The Voyager mission press conference will begin at 2 p.m. EDT (1800 GMT) and be hosted at NASA headquarters in Washington, D.C. You can watch NASA's Voyager announcement live on SPACE.com here, courtesy of NASA TV. The announcement does not indicate if it is about the Voyager 1 mission or Voyager 2 mission, both launched in 1977.

According to NASA's advisory, today's announcement "is related to a paper to be published in the journal Science," and the discovery is embargoed until 2 p.m. EDT. NASA has invited the public to ask questions via Twitter using the agency's #AskNASA hashtag.

The unmanned Voyager 1 and 2 probes were launched in 1977 on a mission to visit all the outer planets of the solar system. After 35 years in space, the twin probes are approaching the edge of our solar system. [<a href="http://www.space.com/17458-voyager-spacecraft-explained-solar-system-infographic.html">See how the Voyager spacecraft worked in this SPACE.com infographic here</a>]
The unmanned Voyager 1 and 2 probes were launched in 1977 on a mission to visit all the outer planets of the solar system. After 35 years in space, the twin probes are approaching the edge of our solar system. [See how the Voyager spacecraft worked in this SPACE.com infographic here]
Credit: Karl Tate, SPACE.com

NASA has two Voyager spacecaft currently on their way out of the solar system.

NASA's Voyager 1 spacecraft is the farthest manmade object from Earth. The probe launched on Sept. 5, 1977and is currently about 11.6 billion miles (18.7 billion kilometers) from Earth. The spacecraft, like its twin Voyager 2, runs on a nuclear power source, which has allowed it to continue operating for just over 36 years.

A long-standing mystery is whether Voyager 1 is still on the edge of the solar system, or actually in interstellar space. For years, Voyager 1 has been traversing a boundary layer of the solar system known as the heliopause as it exits the solar system.

In August, scientists not involved in the Voyager mission published a study suggesting Voyager 1 left the solar system in 2012 in the Astrophysical Journal Letters. But NASA's Voyager 1 mission team and other researchers have said that their data indicated Voyager 1 was still plying through a strange transition zone at the fringe of our solar system.

Voyager 1 and Voyager 2 launched on a so-called "grand tour" of the solar system that ultimately sent the spacecraft on unprecedented flybys of Jupiter, Saturn, Uranus and Neptune.

After completing the "grand tour," the two Voyager probes continued on their separate ways out toward interstellar space. Voyager 2 is currently about 9.4 billion miles (15.2 billion km) from Earth.

Visit SPACE.com today at 2 p.m. EDT (1800 GMT) for  complete coverage of today's Voyager 1 spacecraft announcement.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on SPACE.com.