Kaguya Shoots the Moon

You are looking at the first high-definition video of the Moon, courtesy of Japan’s Kaguya lunar orbiter. The name “Kaguya” is Japanese for “Moon princess.” Launched in September 2007, it captured video with its 2.2 megapixel HDTV camera showing lunar features with an unprecedented level of detail. After nearly 2 years in orbit, it was decommissioned in June 2009 and crashed into the Moon near the lunar south pole.

I try to avoid using YouTube embeds in my blog, as one never knows how long the links will be live. But this video is so beautiful it was worth making an exception. It runs 14 minutes but I think you’ll find it worth your time. This is the view astronauts enjoy from lunar orbit at around 100 km altitude.

You see the stark lunar terrain, an Earthset and Earthrise, and the Sun (which overloads the optics and generates a vertical white bar). The resolution is around 10 meter/pixel. I find the contrast between the colorful Earth and grayscale Moon particularly striking. These are clearly two very different worlds.

I discovered this video browsing online, and though I’d known of Kaguya, I’d missed its spectacular HD videos when they were first released. It didn’t get a lot of media coverage, perhaps because everyone was focused on the real estate market crash. But given the impending Artemis launches, I think this is timely content. Astronauts will soon be enjoying this view for the first time since 1974 — a hiatus of nearly 50 years.

There were many individual frames from Kaguya’s videos that stood out. One in particular caught my eye. It was the Earthrise photo taken when Kaguya emerged from behind the dark side of the Moon. I like to think of the image below as Earthrise 2.

Earthrise 2: The first Earthrise photo was taken in 1968 by the crew of Apollo 8. They used a Hasselblad 500 EL, an excellent film camera for that era, but color film then had limited resolution. The Earthrise shot by Apollo was from a nearly-equatorial orbit, so we saw the Earth in “quarter phase” with its terminator parallel to the lunar horizon. Kaguya’s HD digital camera provided this hi-res update (click to enlarge):

Kaguya’s image was captured from a polar orbit around the Moon, so we can see the Earth in “quarter phase” with its terminator perpendicular to the lunar horizon. From Earth at the time of this photo, we would see a Quarter Moon. The Sun, of course, is to the left in this image and casts long shadows near the lunar south pole. The original image has been flipped so north is up — a convention on maps that is not always used in astrophotography.

It’s exciting to know that, in a few years, we’ll be seeing more hi-def video, this time from the lunar surface. The grainy SD videos from the Apollo era are spectacular for their time, but are going to be blown away by the HD videos from upcoming missions. I also expect a VR experience on  the lunar surface will soon be available.

Next Week in Sky Lights ⇒ DART Disrupts Dimorphos

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Q&A: DART Disrupts Dimorphos