NASA's solar probe, the Parker Solar Probe, will enter the closest distance to the sun in history on Christmas Eve, the 24th. Parker is currently out of communication with Earth and will conduct its mission alone during the Christmas period, resuming communication on the 27th.
Parker flew to a distance of 42.3 million kilometers from the sun two months after its launch in August 2018. This surpassed the previous record of 43.4 million kilometers set by the Helios 2 probe, launched in 1976. The mission's goal is to find the reasons for the rising temperature of the sun's outer atmosphere, the corona, and the origin of solar winds.
According to NASA, Parker will enter a region 6.2 million kilometers from the sun's surface at 8:53 p.m. (Korea Standard Time) on that day. Assuming the distance between the sun and Earth is 1 meter, the distance between the sun and Parker at that time will be just 4 centimeters. This region is where the solar corona exists and is the closest any man-made object has ever approached the sun.
Parker was designed to withstand extremely high temperatures of 1,370 degrees Celsius and intense radiation for solar exploration. The carbon composite thickness of the heat shield protecting Parker from solar heat reaches 11.5 centimeters. However, since the temperature of the corona can reach millions of degrees, Parker will be collecting data while rapidly passing through the corona region. Its speed will be approximately 192 kilometers per second, allowing it to reach Daejeon from Seoul in just one second.
The astronomical community expects to gather new data on solar activity from Parker's mission. Especially, the phenomenon of the corona heating to millions of degrees is still a problem that astronomers have not yet solved. While the sun's surface is only 6,000 degrees, the reason the corona, further from the center of the sun, is hot remains one of the mysteries in astronomy.
There are also expectations that understanding solar winds, which cause communication disruptions on Earth, will broaden. Solar wind, a flow of fine particles emitted from the corona, interacts with Earth's magnetic field to create auroras. However, when solar winds become powerful, high-energy particles enter Earth's atmosphere, causing failures in power grids and electronic devices and disrupting communications. If solar winds can be predicted, it could minimize the chaos caused by sudden communication breakdowns.
Communication with Parker will resume on the 27th, after Christmas. NASA noted, "It takes three days for Parker to approach the sun and return to communicate again," adding, "The data collected from this mission will start to be transmitted sequentially from January next year."
This is not Parker's first close approach to the sun. Last December, it came within 7.26 million kilometers of the sun. The probe will also approach the sun again around July next year, when solar activity is expected to be at its peak.