The China Mail - NASA probe makes closest ever pass by the Sun

Launched in August 2018, the spaceship is on a seven-year mission to deepen scientific understanding of our star and help forecast space-weather events that can affect life on Earth.

Tuesday’s historic fly-by should have occurred at precisely 6:53am (1153 GMT), although mission scientists will have to wait until Friday for confirmation as they lose contact with the craft for several days due to its proximity to the Sun.

If the distance between Earth and the Sun is the equivalent to the length of an American football field, the spacecraft should have been about four yards (meters) from the end zone at the moment of closest approach – known as perihelion.

"This is one example of NASA's bold missions, doing something that no one else has ever done before to answer longstanding questions about our universe," Arik Posner, Parker Solar Probe program scientist said in a statement on Monday.

"We can't wait to receive that first status update from the spacecraft and start receiving the science data in the coming weeks."

So effective is the heat shield, that the probe’s internal instruments remain near room temperature -- around 85F (29C) -- as it explores the Sun's outer atmosphere, called the corona.

Parker will also be moving at a blistering pace of around 430,000 mph (690,000 kph), fast enough to fly from the US capital Washington to Tokyo in under a minute.

"No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory," said Nick Pinkine, mission operations manager at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland.

"We're excited to hear back from the spacecraft when it swings back around the Sun."

By venturing into these extreme conditions, Parker has been helping scientists tackle some of the Sun's biggest mysteries: how the solar wind originates, why the corona is hotter than the surface below, and how coronal mass ejections -- massive clouds of plasma that hurl through space -- are formed.

The Christmas Eve flyby is the first of three record-setting close passes, with the next two -- on March 22, 2025, and June 19, 2025 -- both expected to bring the probe back to a similarly close distance from the Sun.

K.Lam--ThChM