Humanity Just Flew Closer to the Sun Than Ever Before
On Monday, NASA’s Parker Solar Probe passed within 26.55 million miles, breaking a record that has stood for 42 years.
Image: NASA/Johns Hopkins APL/Steve Gribben
A NASA space probe just got closer to the Sun than any human-made object in history.
On Monday at 1:04 PM ET, the Parker Solar Probe passed within 26.55 million miles of the solar surface, breaking a record set in April 1976 by the German-American Helios 2 mission. The probe, which is named after solar astrophysicist Eugene Parker, was launched in August and is conducting its first solar flyby this week. It will inch even nearer to the Sun until November 6, and then swing back out into its deep space orbit to gear up for its next close pass in April 2019.
Over the next seven years, Parker will keep beating its own distance milestones—and, by extension, all of humanity’s—with each flyby. In 2024, when it will make its closest approach just 3.83 million miles from the solar surface. That’s seven times closer than the Helios 2 record it just beat, and will place Parker deep within the Sun’s outer atmosphere (called the corona), where temperatures reach millions of degrees.
Parker can withstand such unimaginable temperatures because the corona is a low density environment. The probe’s heat shield doesn’t interact with many particles, so it will only experience temperatures of around 2,500°F (1,377°C). NASA’s analogy is to imagine putting your hand in a hot oven versus dunking it into a pot of boiling water—the temperatures may be the same, but the water will do more rapid damage because the medium is far denser.
Of course, 2,500°F is still extremely hot. Parker is outfitted with a sophisticated heat shield called the Thermal Protection System (TPS), which is tested to withstand heat up to 3,000°F. Not only does the TPS block the immense radiation of the Sun from damaging the probe’s instrument suite, it is also built to weather the transition back to the cold of deep space, where temperatures are -200°F.
On top of all these superpowers, Parker will eventually reach speeds of around 450,000 mph, which will also make it the fastest human-made object in history.
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