“When NASA’s Juno spacecraft flew past Earth on Oct. 9, 2013, it received a boost in speed of more than 8,800 mph (about 7.3 kilometer per second), which set it on course for a July 4, 2016, rendezvous with Jupiter.
One of Juno’s sensors, a special kind of camera optimized to track faint stars, also had a unique view of the Earth-moon system. The result was an intriguing, low-resolution glimpse of what our world would look like to a visitor from afar.
The cameras that took the images for the movie are located near the pointed tip of one of the spacecraft’s three solar-array arms. They are part of Juno’s Magnetic Field Investigation (MAG) and are normally used to determine the orientation of the magnetic sensors. These cameras look away from the sunlit side of the solar array, so as the spacecraft approached, the system’s four cameras pointed toward Earth. Earth and the moon came into view when Juno was about 600,000 miles (966,000 kilometers) away — about three times the Earth-moon separation.
During the flyby, timing was everything. Juno was traveling about twice as fast as a typical satellite, and the spacecraft itself was spinning at 2 rpm. To assemble a movie that wouldn’t make viewers dizzy, the star tracker had to capture a frame each time the camera was facing Earth at exactly the right instant. The frames were sent to Earth, where they were processed into video format. “
Video and text via NASA Jet Propulsion Laboratory.
“A memo pad that looks as if it has been cut directly out of the earth’s crust. The earth’s surface seems to be whittled away as the pages of the pad are used, and the pattern of the geographical features and the coastal lines changes. A memo pad that lets you enjoy the same kind of sensation you get from diving down into the ocean.”
SANTA AND THE MOON
Peter Barthel, Communicating Astronomy to the Public, May 2012, (12) p13 – 15.
“We have established that illustrators and designers draw moons ad libitum, according to their taste, but often physically incorrect. The most common mistake is the early morning waning moon shown in an evening scene. Our research focussed on Sinterklaas, Santa Claus, and Christmas scenes, with a short side trip to Sint Maarten and Halloween. The apparent lack of knowledge concerning the physics of the moon phases is most likely widespread and not just limited to the countries examined here. Further investigations are however outside the scope of the present research.”
(see more of Popperfont’s Sciencegeek Advent Calendar Extravanganza here)
By DAVID NG
Cor Crikey! And g’day mate! Right now we’re walking up to Hawaii’s Gemini Observatory on the summit of Mauna Kea. It’s got a beaut of a telescope inside, and we’re hoping to find a new planet today.
(Whispering) Here we are at the front door. But we should first give it a bit of space. Patience is important when dealing with telescopes. And we’ve got to be careful with that door. It’s locked! Looks like the observatory doesn’t open for another 20 minutes.
(20 minutes later) Alright mate! Let’s go! (running) Quickly mate! We’re already inside, but we’ve got to move fast! If you look around, you might see that there are other humans around here that will also want to use the telescope, but if you get there first, you’re in there mate. You can use one hand for the controls, and the other to fend the others off.
(Reaching the console) We’re the first here! And it looks like we’ll get to have it to ourselves too. Ripper! Looks pretty complicated, but I’ve been around telescopes all my life and this is definitely an “on” button. But before I press it, let’s first camouflage ourselves behind this adjustable office chair, just in case! I’m going to turn it on now.
(Apparatus makes a noise). Watch out mate! We’ve got to stay extra alert now. Remember – never do this without the supervision of an expert like myself around.
It’s on. And don’t forget to be on the look-out for other humans. We can scare them off by making ourselves look as big as possible – spread your arms wide and look like you’re real pissed. That’s right, like that. Beauty mate! Alright, now let’s go find us some planets…
(7 hours) Did you see that?
(12 days) Did you see that?
(4 week) Did you see that?
(6 weeks) Did you see that?
(7 weeks) Crikey! Did you see that?
(3 months and 1 week) Did you see that?
(4 months) Did you see that?
(5 months and 3 weeks) Did you see that?
(6 months later and looking weary) Well mates, that’s all we have time for in this show. It’s a shame we didn’t find a new planet but that’s sometime how it is in these observatories. See you next time!