[Breaking news update, posted at 8:06 p.m.] NASA has re-established contact with its New Horizons spacecraft after a planned communications blackout as the probe makes humankind’s first flyby of Pluto.
Mission managers who were packed into the New Horizons “mission control” room anxiously waiting to hear from the spacecraft broke into applause.
NASA says its New Horizons spacecraft completed a historic flyby of Pluto on Tuesday, making its closest pass over the small, icy world at 7:49 a.m. ET.
The unmanned, piano-sized spacecraft was expected to be traveling nearly 31,000 miles per hour when it passed about 7,750 miles over Pluto. It’s the first mission to Pluto and its five moons.
Because the spacecraft will be busy gathering data during the flyby, it won’t phone home to update its status until around 9 p.m. ET on Tuesday.
“That’s going to be a very highly anticipated event,” Alan Stern, the mission’s principal investigator said at a briefing Monday.
The wait will be a tense one.
“There’s that small element of danger, so I think we’re all going to breathe the final sigh of relief at 9 p.m., and that’s when we can really call it a successful flyby,” Stern said.
When will you see photos from the flyby? It takes four hours for the probe to get a signal back to Earth, and then NASA has to process the data. Mission managers expect the images from the close encounter to be released online and on NASA TV at 3 p.m. ET on Wednesday.
Scientists on Monday said New Horizons already has settled one debate about Pluto — it’s size. Information gathered by the probe indicates Pluto is 1,473 miles (2,370 kilometers) in diameter. That’s somewhat bigger than earlier estimates, and it means Pluto is larger than all other known solar system objects beyond the orbit of Neptune.
The probe already has beamed back several crisp photos of Pluto and its largest moon, Charon.
“Pluto and Charon are both mind-blowing,” Stern told CNN on Saturday. “I think that the biggest surprise is the complexity we’re seeing in both objects.”
The mission completes what NASA calls the reconnaissance of the classical solar system, and it makes the United States the first nation to send a space probe to every planet from Mercury to Pluto. The probe traveled more than 3 billion miles to reach Pluto.