Ten days after its soft landing on the Moon, Japan’s history-making Smart Lander for Investigating Moon (SLIM) is back in action. The lander had a slight mishap while carrying out its precision landing, ending up on its side, which prevented its solar panels from powering up and left the lander running on batteries. Crucially, the solar panels were pointing West – facing away from the Sun at that time – leaving the team with the hope that as the Moon slowly rotated, sunlight would eventually reach the panels. And so it did, yesterday. SLIM has woken up and even sent back a photo.
Without wasting any time, the team started working on the scientific mission, which has already exceeded expectations for the Japan Aerospace Exploration Agency (JAXA). The goal was a precision pinpoint soft landing within 100 meters (330 feet) of a specific target area. In comparison, the expected landing site for Apollo 11 was an ellipse 20 kilometers by 5 kilometers (12 by 3.1 miles). SLIM appears to have landed just 55 meters (180 feet) from its target, a precision never achieved before on another world.
Despite the slightly askew landing, SLIM deployed its two small rovers – one of which snapped the image of SLIM slanted on the surface – which are exploring their surroundings. Now that power is back on and it doesn’t have to rely on batteries, SLIM is using its cameras to study the interesting rocks near the lander.
Six have been identified and they have been named after dog breeds: Toy Poodle, Shiba Inu, Bulldog, Akita Inu, Kai Ken, and St Bernard. SLIM has begun analyzing the Toy Poodle rock using spectroscopy – a technique that allows us to work out the composition of an object based on its light. Once, Toy Poodle is fully analyzed, SLIM will move on to the next rocks.
While the work on the surface continued, SLIM was also snapped from orbit. On January 22, NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft passed over the landing site and photographed SLIM from orbit. LRO was about 80 kilometers (50 miles) above the Lunar surface at the time. A before-and-after photo shows not only the 2.4 meter-long (8 feet) lander but also the effects of its rocket on the Moon.
The retrorockets lifted the top layer of lunar soil, the regolith, which is darker than what lies below it. It is made of thin, weathered, tiny, and sharp rocks. It is dangerous to instruments and even to humans; Apollo 17 astronaut Harrison H. Schmitt was discovered to be allergic to Moon dust.
The landing site before and after SLIM landed.
Image Credit: NASA/Goddard/Arizona State University
The regolith lifting was seen around India’s Vikram lander last summer and even during the Apollo missions; so much so during Apollo 11 that Buzz Aldrin noted that they were “picking up some dust” as they were about to touch down on the Moon’s surface.
SLIM will now try its best to catch up on lost time and conduct its science mission before the Sun sets on it, and the lander goes back into sleep mode, bracing for the freezing 14-day lunar night.
