This article was originally published by JPL on June 10, 2024. Edited by EarthSky.
Epic solar flare seen from Mars on May 20
Mars scientists have been anticipating epic solar storms since the sun entered a period of maximum activity earlier this year. This peak in the 11 year cycle It is called solar maximum (see video here). Over the past month, NASA's Mars rovers and orbiters have given researchers front-row seats to a series of solar flares and coronal mass ejections (CME) that have reached Mars, in some cases even causing Martian auroras.
This scientific bonanza has offered an unprecedented opportunity to study how such events unfold in deep space, as well as how much radiation exposure the first astronauts on Mars might encounter.
The largest event seen from Mars occurred on May 20 with a solar flare that was later estimated at X12. X flares They are the strongest of several types of solar flares. The Solar Orbiter spacecraft, a joint mission between ESA (European Space Agency) and NASA, saw the flare. It sent X-rays and gamma rays toward the Red Planet, while a subsequent coronal mass ejection launched charged particles. Moving at the speed of light, the flare's x-rays and gamma rays arrived first, while the charged particles followed slightly behind, reaching Mars in just tens of minutes.
Images of radiation hitting Mars
Analysts of the Moon to Mars Space Weather Analysis Office at NASA's Goddard Space Flight Center in Greenbelt, Maryland, closely followed the development of space weather. They also pointed out the possibility of charged particles entering after coronal mass ejection.
During the May 20 event, so much energy from the storm hit the surface that the black-and-white images from Curiosity's navigation cameras danced with the “snow.” It showed white streaks and specks caused by charged particles hitting the chambers.
Similarly, energy from solar particles flooded NASA's chamber in 2001. Mars Odyssey uses the orbiter for guidance. This bombardment momentarily caused it to go out. (Odyssey has other ways of finding its way and recovered the camera within an hour.) Even with the brief lapse in its star chamber, the orbiter collected vital data on X-rays, gamma rays and charged particles using its high-energy neutron detector.
Additionally, this was not Odyssey's first encounter with a solar flare. In 2003, solar particles from a huge X45 solar flare fried Odyssey's radiation detector, which was designed to measure such events.
Space weather on Mars affects future astronauts
If the astronauts had been next to NASA's Curiosity rover on Mars at that time, they would have received a radiation dose of 8,100 micrograys, equivalent to 30 chest X-rays. While not fatal, it was the largest increase measured by Curiosity's radiation assessment detector, or RADsince the rover landed 12 years ago.
RAD data will help scientists plan for the highest level of radiation exposure astronauts could encounter. Astronauts could use the Martian landscape as protection.
The main researcher of the RAD, Don Hassler of the Solar System Science and Exploration Division of the Southwest Research Institute in Boulder, Colorado, saying:
Cliffs or lava tubes would provide additional shielding for an astronaut of such an event. In Mars orbit or deep space, the dose rate would be significantly higher.
Auroras over Mars
Over the past month, NASA's Mars rovers and orbiters have given researchers front-row seats to a series of solar flares and coronal mass ejections that have reached Mars. In some cases, they have even caused Martian auroras.
from NASA MAVEN (Mars Atmosphere and Volatile EvolutioN) captured bright auroras over the planet. The way these auroras occur is different from those seen on Earth.
A robust magnetic field is what protects our planet from charged particles. And that magnetic field typically limits auroras to regions near the poles. He current solar cycle – perhaps at its maximum – is the reason behind the recent auroras seen as far south as Alabama.
However, Mars lost its internally generated magnetic field in the ancient past, so there is no protection against the barrage of energetic particles. When charged particles hit the Martian atmosphere, auroras are produced that envelop the entire planet.
During solar events, the sun releases a wide range of energetic particles. Only the most energetic can reach the surface for RAD to measure. MAVEN's Solar Energetic Particle Instrument can detect slightly less energetic particles, including those that cause auroras.
Scientists can use data from that instrument to reconstruct a timeline of every minute as the solar particles screamed past, meticulously breaking down how the event evolved.
Christina Lee from the University of California, Berkeley Space Sciences Laboratory and MAVEN Space Weather Lead, saying:
This was the largest solar energetic particle event MAVEN has ever seen. There have been several solar events in recent weeks, so we were seeing wave after wave of particles hitting Mars.
How MAVEN and Curiosity study solar flares
Watch this video to learn how NASA's MAVEN and the agency's Curiosity rover study solar flares and radiation on Mars during solar maximum, a period when the sun is at its most active.
Bottom line: The sun hurls its particles into the solar system, and studying this space weather on Mars helps us understand what future astronauts might face there.
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