What if the sun never set?
Astronauts aboard the International Space Station occasionally experience that very phenomenon, and it’s captured in the video above in all its beautiful oddness. Here’s how it works:
The ISS doesn’t travel around the Earth’s middle. Rather, it follows a near-polar orbit. As it flies along its tilted north-south path, orbiting the Earth every 90 minutes, this orbit lets it see much more of the Earth beneath it. Occasionally, it happens to travel along the line between night and day, and that’s where this cool scene unfolds.
Along Earth’s “terminator” (the line between light and dark), if you looked out the window of the ISS you’d see the Sun dip in the sky, but climb again without setting. In the video, the orbit begins east of London, then extends southward along the terminator until crossing near the South Pole. The ISS then orbits back up toward the north, hovering above the terminator in permanent daylight until it reaches a point just east of where it began.
The Earth’s terminator line:
(Video by NASACrewEarthObs)
That’s over 1,000 images of the planet Mercury stitched together in a copper-blue disco ball of hypnotic animation. Launched in 2004, NASA’s MESSENGER spacecraft has been studying the smallest member of the Solar System for nearly two years with phenomenal success.
A single solar day on Mercury takes over 58 Earth days, so this GIF’s rotation would take you nearly two months to see with the naked eye … you know, should you be in space, near Mercury. Check out another shadowy video of a Mercurial day from NASA.
BONUS: Did you know that craters on Mercury are named for authors, artists and musicians? Dr. Seuss and Andy Warhol each have one.
Sonic Transit of Venus
Robert Alexander is an astronomical “sonification specialist”. He uses his musical training to take non-audible data and convert them into soundscapes to provide NASA scientists with a novel way to study the emissions from our Sun.
NASA satellites are constantly collecting data along the extreme range of emissions from the Sun. Alexander first compresses days of data into just seconds and then assigns different emissions (such as the various excited states of carbon) to different tones.
Above, he used signals collected during the 2012 Transit of Venus to help create a larger musical composition (listen to the full 17-minute version here). Listen to more of his solarsonic creations at NPR.
Want to know more about the different families of solar emissions? Check out the false-color palette of our solar disk as seen by NASA’s SDO satellite.
Eyes on the Stars
Twenty-seven years ago today, seven heroic explorers lost their lives in the name of science and discovery. When the space shuttle Challenger exploded after liftoff on January 28, 1986, their lives were tragically extinguished … but thankfully our quest for knowledge on Earth and beyond was not.
Ronald McNair was one of those seven astronauts. This is a beautiful animated tribute to his life. He grew up in a time when the color of his skin kept him from checking out a library book, much less dreaming of becoming an astronaut. But he persevered, and refused to wait for permission before setting out in search of what he wanted to discover, And discover he did.
That’s the beautiful thing about the space program. Sure, the experiments take place in orbit. But they inspire discovery on every square mile of the Earth they orbit. They remind us that anything is possible, with hard work and dedication, in the laboratory or the segregated library. Dr. Ron McNair tragically lost his life in pursuit of scientific progress, but that cultural progress lives on. It says that girl or boy or black or white or anywhere in between any two points on the spectrum of the human experience that you want to place your labels … you can do it. You define “it”.
Beyond the direct technological and economic benefits of NASA and all of the science they inspire, this shows how the desire to discover transcends the lab coat or the textbook and lands square in our own lap. Also, I think there’s something in my eye.
Don’t wait for permission. Eyes on the stars. Head to the future.
(via Bad Astronomy)
If you look at the Sun (which you shouldn’t, ever), you just see white light (for the second or so before your retinas are permanently scorched. That’s a mixture of all wavelengths of the electromagnetic spectrum that our eyes respond to, between 390 and 700 nanometers (or about 3,900 to 7,000 angstroms). And there is a lot we can learn about the Sun by viewing it in that range, from studying its undulating surface swirls to its rotation.
But scientists at places like NASA can learn even more by extending their “eyes” beyond the visible.That’s what this new mosaic from the Solar Dynamics Observatory shows us. It represents all of SDO’s detectable wavelengths and the ions and temperatures that those wavelengths represent. Viewing each of those can tell us a deeper, richer story of the solar physics at work in and on the fusion-powered energy source that feeds our planet.
I’ve captured the false colored hues that NASA scientists assign to each and put it in a digital palette. I can’t help but feel a bit amazed at not only the extreme temperatures at play (millions of Kelvin!) but also the extreme beauty. Our Sun is the best sun.
ATTENTION folks, there is currently an astronaut posting to Tumblr from space. I repeat, there is a human being, that is currently in freakin’ SPACE, posting pictures (from said SPACE) to their Tumblr blog.
There are things, called words, that are failing me, about the other things, that I am feeling.
Expedition 35 Commander Chris Hadfield: You sir, are cooler than a polar bear’s toenails.
(He’s also on Twitter)
Buzzing the Moon
NASA’s twin GRAIL spacecraft, Ebb and Flow, crashed into the Moon recently. Their fuel was exhausted, their mission to map lunar gravity complete. Fare thee well, fine ships. The video above is a view of their final days, skimming a mere 6 miles above the gorgeous lunar surface. I’m jealous.
“You are go for fly-by, GRAIL. The pattern is not full.”
The two spacecraft orbited our rocky satellite, one lagging behind the other, sensing slight fluctuations in each other’s orbits caused by slight differences in the Moon’s gravity. For instance one passed over a spot with slightly stronger pull, it would dip ever so slightly. Communicating via microwaves, the other spacecraft would sense that dip. And so they flew, bobbing and weaving and mapping.
Technically, the Earth and the Moon aren’t perfect spheres. However, for all intents and purposes we can pretend they are, as they are certainly more perfectly round than a billiard ball. The Earth actually bulges slightly in the middle from the tug of the Moon’s gravity, like a tectonic high tide.
We know that everything with mass exerts gravity. Even the coffee cup currently next to me is pulling me toward it, and I’m pulling it toward me, however infinitesimally imperceptible that pull may be. Actually, that tug might be because I need coffee, but you get the idea. What most people don’t realize is that objects like the Earth and Moon don’t have evenly distributed mass, and likewise don’t have completely even gravity.
Everywhere on the Moon that there’s slightly denser, heavier rock, there’s slightly more gravity exerted above that spot. The GRAIL mission mapped the Moon’s blips and bulges in the greatest detail ever, giving us this abstract-art-like map:
If you want to read more about Earth’s lumpy gravity, check out this post by Phil Plait.