An astronaut in his suit could get up to three million miles from the sun before getting into serious trouble, but NASA’s spacecraft can do much more. Considering that the sun is 93 million miles away from Earth, humans can get really close. The sun is a very energetic celestial body, constantly emanating energy and solar wind.
For decades the sun has been the most elusive object in the solar system, but NASA never gave up on the idea of getting up and close. Understanding the sun is understanding life on Earth, and therefore the interest for science is priceless. Moreover, modern technologies and space exploration, and life on planets with thin atmospheres, are seriously impacted by solar activity.
NASA has reached a breakthrough in solar exploration, literally “touching the Sun” with the Parker Solar Probe. The probe submerged in the corona, or sun’s atmosphere reaching 18.8 solar radii (around 8.1 million miles) above the solar surface. Data from the region’s conditions told scientists it had crossed the Alfvén critical surface for the first time. Take into consideration that 20 solar radii are about 91 percent of Earth’s distance from the sun.
Pushing The Limits
Still, today NASA is unsure of how close the probe can get to the sun without being affected. Fifty years ago, getting as close as the Parker probe has gotten would have been impossible. Technology advancements made in sun heat shields, with light yet durable and efficient materials, have pushed solar science. The Parker Solar Probe was launched three years ago and is making history just now. However, the spacecraft was in design and development for decades.
Parker continues to circle closer to the solar surface making new discoveries and pushing the limits. NASA says that the data they have obtained during these close encounters would have never been obtained by studying the sun from a distance. Unlike rocky planets like Mars and Earth, the sun does not have a solid surface, so a probe will never touch the ground.
The sun is a giant superheated atmosphere bound by gravity and magnetic forces. As the heat and magnetic forces push material away from the sun, it reaches a point where gravity no longer contains the material. This point is known as the Alfvén critical surface. It marks the end of the solar atmosphere and the beginning of the solar wind. And the Parker probe just went past it several times. So will this be the closest people will ever get to the sun safely? As NASA develops new technology, people can expect closer encounters in the years ahead.
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