NASA’s Parker Solar Probe is set to break a record tomorrow, becoming the closest-ever human-made object to the sun. The probe will break its own previous record, coming within 8.4 million miles of the sun’s surface and traveling at 289,927 miles per hour.
This will be the probe’s sixth flyby of the sun since it was launched in 2018. As it orbits around the sun, it gets gradually closer and closer with each pass, and over the summer it got an extra boost by using the gravity of Venus to adjust its trajectory. In July this year, the probe came within just 518 miles of the surface of Venus, and the gravitational assist from this maneuver allowed the probe to get 3.25 million miles closer to the sun than its last pass in June.
This flyby will also be the first time that the probe will pass within 0.1 AU of the sun. An AU, or astronomical unit, is a measurement of distance where 1 AU is equal to the average distance between the Earth and the sun.
“After our last orbit — during which we started science operations much farther out than this encounter — we’re returning our focus to the solar wind closer to the Sun,” said Nour Raouafi, Parker Solar Probe project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, in a statement. “We always wonder if we’ll see something new as we get closer and closer. And as the solar cycle rises and the Sun becomes more active, we’ll be able to observe that activity from an unprecedented vantage point.”
The probe is collecting data on the sun’s activity to understand more about its outer atmosphere, called the corona. The approaches allow the probe to collect measurements from closer to the sun than ever before, and also to capture images of the corona up close.
Scientists want to know more about solar wind, a stream of charged particles released from the corona, as the wind can travel through the solar system and affect space weather. Here on Earth, space weather affects satellite communications and the electrical systems of craft in orbit, and the radiation can even affect astronauts too.