Coronal Mass Ejection to pass Earth, Messenger and Juno

The European Space Agency (ESA)/NASA Solar and Heliospheric Observatory captured this image of a coronal mass ejection as it left the sun in the direction of Earth and Mercury on July 16, 2013, at 4:24 a.m. EDT. 

Credit: ESA&NASA/SOHO

On July 16, 2013, at 12:09 a.m. EDT, the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of particles into space that can reach Earth one to three days later.

These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.

Experimental NASA research models, based on observations from NASA's Solar Terrestrial Relations Observatory, show that the CME left the sun at speeds of around 560 miles per second, which is a fairly typical speed for CMEs.

Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth's magnetic envelope, the magnetosphere, for an extended period of time.

The CME's magnetic fields peel back the outermost layers of Earth's fields changing their very shape. Magnetic storms can degrade communication signals and cause unexpected electrical surges in power grids.

They also can cause aurora. Storms are less frequent during solar minimum, but as the sun's activity ramps up every 11 years toward solar maximum – currently expected in late 2013—large storms occur more frequently.

Messenger Spacecraft

The CME may also pass by the Messenger and Juno spacecraft and their mission operators have been notified. If warranted, operators can put spacecraft into safe mode to protect the instruments from the solar material.

In the past, geomagnetic storms caused by CMEs of this strength have usually been mild.

NASA Juno: Jupiter-Bound Probe Changes Orbit in Deep Space

Juno, NASA's Jupiter-bound probe fired its main engine Thursday (Aug. 30) to help set up a speed-boosting flyby of Earth next year.

The engine burn — which took place when the Juno spacecraft was about 300 million miles (483 million kilometers) from Earth — began at 6:57 p.m. EDT (2257 GMT) Thursday and lasted nearly 30 minutes.

It appears to have worked according to plan, changing the probe's velocity by about 770 mph (1,240 kph), researchers said.

"This first and successful main engine burn is the payoff for a lot of hard work and planning by the operations team," Juno project manager Rick Nybakken, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement.

"We started detailed preparations for this maneuver earlier this year, and over the last five months we've been characterizing and configuring the spacecraft, primarily in the propulsion and thermal systems," he added.

After another burn this Tuesday (Sept. 4), Juno should be on course for its Earth flyby on Oct. 9, 2013, which will bring the probe within 310 miles (500 km) of our planet. Earth's gravity will give the spacecraft a big push, boosting its velocity by 16,330 mph (26,280 kph) and placing Juno on its final path to Jupiter, researchers said. Juno was launched on Aug. 5, 2011 and is slated to arrive at the solar system's largest planet on July 4, 2016. Once there, Juno will orbit Jupiter 33 times from pole to pole, using its eight science instruments to peer beneath the gas giant's thick clouds. (The spacecraft takes its name from the goddess Juno, who was able to see through the clouds devised by her husband Jupiter in an attempt to hide his mischief.) The main goal of the $1.1 billion mission is to learn about Jupiter's atmosphere, magnetosphere, composition and origins, and to determine if the planet has a solid core, researchers said.

NASA's Juno Mission: Probe to Examine Jupiter's Biggest Secrets

Jupiter is probably the best place in the solar system to study how the magnetic fields of planets are generated. 

The Juno spacecraft will make the five-year, 400-million-mile voyage to Jupiter and orbit the planet, collecting data for more than one Earth year.

CREDIT: NASA/JPL-Caltech

A NASA probe that is traveling through space on its way to Jupiter is expected to help astronomers unlock mysteries about the largest planet in our solar system when it arrives there in 2016.

NASA's Juno mission was launched in August 2011 to study how Jupiter formed and evolved. After a five-year journey, the spacecraft is expected to arrive at the gas giant planet in August 2016.

Jupiter has long intrigued astronomers, from the planet's distinct surface features and complex weather systems to its mysterious origin and evolution, said Fran Bagenal, a professor of astrophysical and planetary sciences at the University of Colorado in Boulder, and a co-investigator on the Juno mission.

"People have been looking at this exterior since the time of Galileo," she said. "[But] we know very little of what's inside. We're sending Juno out there to Jupiter to try to understand the origin and evolution of Jupiter, [to] try to explain how much water there is, what it's like inside, what the atmosphere is like."

Bagenal discussed the exciting results the Juno mission is expected to yield in a session on June 11 here at the 220th meeting of the American Astronomical Society.

Once the solar-powered Juno spacecraft is captured into orbit around Jupiter, the probe will map the planet's magnetic and gravitational fields to learn more about the interior structure of Jupiter.

[Photos: NASA's Juno Mission to Jupiter]