NASA has its sights set on the moon, with plans to return astronauts to the lunar surface by 2026 and establish a permanent presence by the 2030s. However, the moon is far from being a hospitable environment for humans.
Cosmic rays from distant stars and galaxies, along with solar energetic particles from the sun, constantly bombard the lunar surface. Exposure to these particles can pose significant health risks to humans.
Galactic cosmic rays and solar energetic particles are both high-energy particles that travel at nearly the speed of light.
Galactic cosmic radiation reaches the moon in a relatively constant stream, whereas energetic particles from the sun can arrive in powerful bursts. These particles can penetrate human tissue and elevate the risk of cancer.
Earth benefits from a magnetic field that acts as a shield against high-energy particles from space. However, the moon lacks a magnetic field, leaving its surface susceptible to bombardment by these particles.
During a major solar energetic particle event, the radiation dose an astronaut receives inside a space suit could be more than 1,000 times the amount someone on Earth would receive. This would surpass an astronaut’s recommended lifetime exposure limit by tenfold.
NASA’s Artemis program, initiated in 2017, aims to reestablish a human presence on the moon for the first time since 1972. My colleagues and I at the University of Michigan's CLEAR center, the Center for All-Clear SEP Forecast, are dedicated to predicting these solar particle ejections. Accurately forecasting these events could help safeguard future Artemis crew members.
Sun Gears Up for Peak Activity
Get ready for a fiery show! The sun is nearing the peak of its 11-year activity cycle. This means the sun's magnetic field is getting stronger, leading to increased solar flares and coronal mass ejections (CMEs). These powerful eruptions can unleash energetic particles that pose a risk to astronauts and spacecraft in space.
The good news? We can predict the general trend of the sun's activity. The bad news? Pinpointing the exact timing and intensity of each event is tricky.
This timing is especially crucial for the Artemis III mission, aiming to land astronauts on the Moon in 2026, right around the solar maximum. To protect future lunar explorers, scientists are developing a more precise warning system for these solar outbursts.
Sun Storms: Predicting the Fury
Imagine a more precise forecast for space weather! This is exactly what NASA's new initiative, CLEAR, aims to achieve.
Currently, warnings for solar particle events rely on spotting them after they happen – like a weather report based on yesterday's storm. CLEAR aims to change this by predicting these events before they erupt.
This early warning is crucial for future lunar missions. By the time Earth receives a solar flare warning, astronauts on the Moon would have very little time to find shelter. CLEAR's goal is to predict these events with a lead time of over 24 hours.
So, how will they do this? Scientists at CLEAR believe the sun's magnetic field holds the key. By studying its strength and complexity in specific regions, they hope to identify patterns that precede solar outbursts.
Using data from ground and space telescopes, CLEAR will build machine learning models to analyze these patterns and predict solar events. This will not only provide a heads-up for incoming storms but also predict when it's safe for astronauts to emerge from shelter.
With CLEAR, space missions can navigate the Sun's fury with greater confidence, paving the way for a safer future of lunar exploration.