A burst of radioactive solar particles has erupted from the Sun, streaking toward Earth at 900 miles per second, NASA has announced.

The event, called a coronal mass ejection, or CME, while not occurring as frequently as solar flares, is still a common phenomenon. This time, however, rather than projecting out into space, it’s headed straight for Earth.

Given the direction and speed of the CME, Science World Report explains, mild to moderate effects may be felt as soon as today.

When a CME strikes the Earth, the traveling body of solar energetic particles can – on rare occasion – causes a significant enough geomagnetic storm to disrupt the Earth’s magnetosphere. Results may include stronger aurorae around the Earth’s magnetic poles, disruption of radio transmissions and even damage to satellites and electrical transmission facilities, which could cause power outages.

NASA’s Solar Terrestrial Relations Observatory and ESA/NASA’s Solar and Heliospheric Observatory reportedly observed the event, while experimental research models have measured its relative speed.

NASA’s models predict two of its space instruments, the Spitzer and MESSENGER spacecraft, will be affected by the solar blast, and the space agency has alerted mission scientists to take steps preventing particle radiation from damaging on-board instruments.

The Spitzer Space Telescope is an infrared space observatory launched in 2003 that has returned stunning photos of distant galaxies to Earth and became the first telescope in history to visually identify planets in other solar systems.

MESSENGER, an acronym of MErcury Surface, Space ENvironment, GEochemistry, and Ranging, was launched in 2004 and became the first spacecraft ever to orbit the planet Mercury.