Spaceflight Insider

Once in a Blue Moon: International Space Station transits Selene

The International Space Station passes in front of the Moon in this image capture on Sunday, Aug. 2, 2015. Photo Credit: Bill Ingalls / NASA

The International Space Station passes in front of the Moon in this image capture on Sunday, Aug. 2, 2015. (Click to enlarge.) Photo Credit: Bill Ingalls / NASA

While a Blue Moon takes place rarely, a transit of the International Space Station occurs briefly, and both instances took place over the course of this past weekend. According to one of NASA’s photographers, a recent transit of the ISS in front of the dusty lunar terrain lasted just .82 of a second. The imagery captured from this moment had made a far more lasting impression.

The images helped to conclude a weekend that held a particular focus on our nearest celestial neighbor.

After the “Blue Moon” that took place on Friday, July 31, NASA photographers worked to capture the transit of the orbiting laboratory in front of the Moon’s disk.

While the photographers working on this effort accomplished the feat with relative ease, it is a little more difficult than just aiming one’s camera at the Moon and snapping a picture.

“This is not an extremely difficult photograph to make. The biggest part is time preparing, doing your homework collecting the data on when and where the pass will be and then knowing your equipment’s capabilities and limitations. Finally, it’s all about getting to your location and hoping for good weather! This was not our first attempt, so learning from your mistakes and trying again is always the lesson,” NASA Headquarters’ Senior Contract Photographer Bill Ingalls told SpaceFlight Insider.

International Space Station arcs across the night time sky. Photo Credit Bill Ingalls NASA posted on SpaceFlight Insider

Elements of the ISS have been on orbit since 1998 and it currently is home to six astronauts. Photo Credit: Bill Ingalls / NASA

A “Blue Moon” occurs whenever there are two full Moons within a single calendar month (except for the month of February). The phrase can be traced back to around 1528 and is now used as a way of denoting a rare occurrence. In terms of astronomy, outside of atmospheric haze, there is no “Blue Moon.”

Two days after the recent Blue Moon, in the early hours of Sunday, Aug. 2, the ISS made its pass. Ingalls, joined by fellow NASA photographer Joel Kowsky, worked to capture the station’s pass.

The station was moving at an estimated speed of some five miles per second at the time. The speed and brief nature of the event would make capturing the event challenging for the novice photographer.

While the image might lend the appearance that the station is in close proximity of the Moon, the truth is the ISS is approximately 250 miles (402 km) above the Earth and the Moon orbits about 250,000 miles (402,336 km) above that.

The ISS is currently called home by the six crew members of Expedition 44. The outpost’s current residents include NASA astronauts Scott Kelly and Kjell Lindgren, Russian Cosmonauts Gennady Padalka, Mikhail Kornienko, and Oleg Kononenko, and Japan Aerospace Exploration Agency (JAXA) astronaut Kimiya Yui. Six is considered to be the station’s full compliment.

Parts of the International Space Station have been on orbit since 1998 when they were sent aloft by Russian Proton and NASA’s Space Shuttle Endeavour. Since that time, space agency’s across the globe have contributed to the expansion and use of the facility.

Selene is the name of the Greek goddess of the Moon. The daughter of Hyperion and Theia, she fell in love with the shepherd Endymion, who Zeus made immortal and eternally asleep. Each night, Selene would visit him in his resting place at Mount Latmos located in what is present-day Turkey.

The NASA photographers who captured this event did not have to travel so far as Turkey to capture these stunning images, they only had to drive to Woodford, Virginia, and to patiently wait for the transit to take place. NASA has photographers at all of its centers and most of its facilities across the United States.


Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

Reader Comments

Why don’t you report where the photo was taken? A lot of effort must have gone into finding the right spot at the right time, especially as the photographer nailed the pass crossing the center of the Moon’s disc.

Hi Rowland,
The image was taken in Woodford, Virginia.
Sincerely, Jason Rhian – Editor, SpaceFlight Insider

I live in The Colony, Texas and was aware of a possible Blue Moon transit in our area over a month ago. I continued monitoring the transit center line up until 1 hour before the ISS was to cross the moon. I drove to the center line n Frisco, Texas north of Dallas and was able to record on video the blue moon transit on Saturday August 1st @ 6:07 am from Frisco, Texas. I was worried about the clouds all day long, but it mostly cleared except for a high thin cloud layer that diffused the moon’s light which caused the ISS to disappear just before it crossed the moon. You can tell it was a dead center transit. To see a blue moon is rare, viewing the ISS transiting the moon is rare. But seeing the ISS transit a blue moon is extremely rare and something that I will probably never be able to do again. I am hoping the astronauts on board the ISS will be able to see my video one day.

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