In a major milestone, the crew of NASA’s Artemis II mission has reached the moon’s ‘sphere of influence’. It is the critical point at which the moon’s gravity is stronger than Earth’s on the spacecraft.
The Orion capsule entered the sphere around 12:41 a.m. ET on Monday, highlighting a significant advance in the mission that shows the astronauts are in close proximity to the moon, ready to fly past the far side of the moon.
For NASA, crossing the threshold is of great significance as this is the first time the crew members have entered the sphere of influence since the Apollo 17 mission in 1972.
The transition came after four days, six hours and two minutes. Right now, Orion is about 39,000 miles (62,800 km) from the moon and 232,000 miles (373,400 km) from Earth.
According to Lori Glaze, deputy administrator of NASA’s Exploration Systems Development Mission, “We are all extremely excited for tomorrow. Our flight operations team and our science team are ready for the first lunar flight in more than 50 years.”
Apollo 16 astronaut Charlie Duke sent a heartwarming message to the crew of Artemis II: “John Young and I landed on the moon in 1972 in a lunar module we called Orion. I’m glad to see another kind of Orion helping return people to the moon as America charts a course to the lunar surface.”
The flyby is expected to last approximately 6 hours. During this historic journey, astronauts will hopefully observe the far side of the moon and capture features that remain hidden and accessible to astronauts due to the prevailing darkness.
The mission will experience a planned communications outage of about 40 minutes as Orion passes behind the moon. During this period, the moon blocks radio signals that provide a connection between the Deep Space Network on Earth and spacecraft.
If the plan goes smoothly, the Artemis II astronauts could set the record by traveling further from Earth than any human ever before.
What will Artemis II astronauts observe on the far side of the moon?
According to NASA, the crew successfully completed a demonstration of manual piloting and revised their lunar flight plan, such as assessing features to analyze and photograph.
The astronauts will observe geological features on the far side, including the Orientale Basin, a 930-kilometer-wide impact basin with multiple rings in the moon’s southern hemisphere, as reported by Nature.
According to Kelsey Young, chief lunar scientist of Artemis II, “Orientale is of great importance in understanding impact craters throughout the solar system.”
Other craters, such as the 64-kilometer-wide Ohm Crater, with a central peak rising above the lava flows on the floor, and the 9-kilometer-wide Pierazzo Crater, will be illuminated during the flight.
The crew members will also witness the subtle changes in the lunar topography, including the moon’s color and brightness.
