Though only about half of all lunar landing attempts have succeeded without crashing, space fans will likely get many spectacular Earth and moon photos along the way, like the latest one beamed back by Japan: Its uncrewed SLIM mission, short for Smart Lander for Investigating the Moon, captured a rare snapshot of Earth looming over the moon, though you might have to squint to see it. Japan, illuminated at dawn, is circled on Earth in the picture.
“When the SLIM team first saw this image, they wondered… what is that white dot under the Earth?!” said JAXA, NASA‘s Japanese counterpart, on X (formerly known as Twitter) on Dec. 20.
At the time the photo was taken in September, the spacecraft was over 60,000 miles away from our home planet.
Today, SLIM is much closer to the moon than Earth and is expected to enter lunar orbit in less than a week.
JAXA will descend toward the lunar surface for its landing on Jan. 20. That will put it a few weeks ahead of U.S.-based Astrobotic Technologies’ moon landing effort, which will try to bring five NASA instruments to the surface, among other payloads. The SLIM mission follows private Japanese company ispace’s failed lunar landing in April.
The reason the spacecraft is seen traveling farther from the moon in this navigation camera image is a result of SLIM’s special fuel-saving trajectory, said Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics.
Credit: JIJI Press / AFP / Japan OUT via Getty Images
When the spacecraft reaches the point in space where the gravitational pulls of Earth and the sun are balanced, it can change direction rather easily, without having to fight the tugs of either the planet or the star, he told Mashable.
“With a tiny spritz of the rocket thruster, you can fall back toward the moon on a path that will pass the moon relatively slowly, allowing you to land easily,” he said. “The downside is that it takes several months instead of a few days to get there from Earth.”
While the spacecraft flies on this leisurely journey, the moon continues to do its thing: circle Earth each month.
“Over several months, the moon whizzes around the Earth several times,” McDowell explained, “so during this, sometimes relative to SLIM, it’s on the same side of the Earth, and sometimes it is on the other side.”
The SLIM mission launched from the Tanegashima Space Center in Japan on Sept. 7 and is expected to touch down near Shioli crater on the moon’s near side. Its goal is to demonstrate a so-called “pinpoint landing” with an accuracy of less than 100 yards, a level of precision unprecedented for moon landings. Most landing targets are many square-miles in scope.
In August, India became the fourth country to land on the moon, joining an elite cadre of space-faring nations — the former Soviet Union, United States, and China — who have achieved this feat. The accomplishment came mere days after the Russian space agency Roscosmos lost its Luna-25 robotic spacecraft, which had been orbiting the moon but apparently crashed after a botched flight maneuver. The dueling missions were both trying to set their crewless spacecraft down near the south pole region.
About 60 years have passed since the first uncrewed moon landings, but touching down remains onerous. The moon’s atmosphere is very thin, providing virtually no drag to slow a spacecraft down as it approaches the ground. Furthermore, there are no GPS systems on the moon to help guide a craft to its landing spot.
Several nations and private companies have set their sights on the moon’s south pole because of its ice, thought to be buried there in permanently shadowed craters. The natural resource is coveted because it could supply drinking water, oxygen, and rocket fuel for future missions, ushering a new era in spaceflight.
