|A NASA rendering of the Parker Solar Probe, which will get closer to Earth’s star than ever before Illustration by Johns Hopkins University Applied Physics Laboratory|
In September 2018, NASA plans to launch a probe that will journey nearly 90 million miles, eventually flying within 3.8 million miles of the sun. The Parker Solar Probe is expected to reach the sun's outer envelope of fiery gases, known as the corona, by November of that year, providing new insights not only into our home star but into all stars--which is no small thing, given that the closest star system is an unreachable four light-years away. That's 24 trillion miles. The sun, just 93 million miles away, is well within our reach.
That doesn't mean getting there is easy. Even as NASA probes have sailed past Pluto and out of the solar system entirely, the sun has mostly been a no-go zone. Designing a spacecraft tough enough to take the sun's thermal punishment has proved difficult--not that that's stopped astronomers from trying. All the way back in 1958, Eugene Parker--a young physicist at the University of Chicago, whose name the new spacecraft bears--published a paper about what we now call solar wind: the high-speed storms of stellar particles and magnetism that stream from the sun. Ever since his discovery, Parker, now 89, has been campaigning for a close-up mission to the sun. At last the technology is available.
After its launch, the unmanned spacecraft will enter a preliminary solar orbit and then make seven flybys of Venus, using the planet's gravity to edge closer and closer to the sun. Ultimately, the ship will be so close that it will make a single trip around the sun in just 88 days--a quick trip compared with Earth's poky 365 days. At its peak speeds, the Parker Solar Probe will move fast enough to get from Philadelphia to Washington in a second.